G'day,

Wing mast is included in the plans, or wil be when I have done the
building instructions.  Pretty easy to build if you can use a vacuum
pump, which in turn is pretty easy once you have had some  practice.
I am not a big fan of glassing foam without using a vacuum to increase
the bonding area on the foam (all the open cells are full of air
without a vacuum), so bagging the whole thing is not a bad idea.  The
beams also need bagging.

regards,

Rob

On Sat, Jul 5, 2008 at 5:57 PM, chesterdave <chesterdave@...> wrote:
> Hey Rob,
> I'm from Ocean Shores, just north of Byron Bay so a delivery price
> would be good. As for the mast, what would you recomend? Is it
> possible to build a wing mast at home? Is this included in the plans?
> Again thanks for all your help,
>
> DAVE
>
> --- In harryproa@..., "Rob Denney" <harryproa@...>
> wrote:
>>
>> G'day,
>>
>> No problem using foam, nor using the Farrier method, except it is
> very
>> time consuming to prepare (you virtually strip plank half a hull),
> to
>> build (lots of screws, some heating of panels) and to complete (lots
>> of fairing as the foam distorts as well as bends). The windward
> hull
>> deck is flat, so there is not much point in using the planked foam
>> method there. If you want the lee hull to have rounded decks
> instead
>> of flat ones with big edge radii then stripping is the way to get
>> this.
>>
>> A single rig is no problem, Youri has put an 18 sq m on the race
>> version. I think this is as big as you would want on the camper.
>> Are you having a wing mast?
>>
>> 15 sheets is 43 sq m, should be enough (I missed out the hard bit of
>> trampoline, and there may be a bit more in the hatch than I allowed
>> for.
>>
>> Happy to get you the materials. I will get a quote on Monday and
> let
>> you know. Where abouts in northern NSW? Will you pick it up from
>> Sydney, or shall I get a delivery price?
>>
>> regards,
>>
>> Rob
>>
>>
>>
>>
>> On Fri, Jul 4, 2008 at 5:47 PM, chesterdave <chesterdave@...> wrote:
>> > Hi Rob,
>> > Thanks for the prompt reply, so the general idea flying round
>> > in my head is for a foam version of the camping elementarry,
>> > Is it possible to build using the vertical strip method in a
> female
>> > mould like the farrier trimarans?
>> > I would like to do some solo sailing so a single mast is probably
>> > the better idea, so the schooner rig has i think 22 sq m of sail
> and
>> > the single rig 11, can a single rig of say 15 - 18 sq m of sail be
>> > used?
>> > I've done some (VERY ROUGH) calculations and decided 15 sheets of
>> > 2400 x 1200 foam would be plenty, does this sound right?
>> > Is it possible to source the materials from you? I live in
> northern
>> > NSW by the way, again thanks for the prompt reply to my previous
>> > post, its nice to comunicate with a designer that actually wants
> to
>> > help
>> >
>> > Thanks,
>> > DAVE
>> >
>> >
>> > --- In harryproa@..., "Rob Denney" <harryproa@>
>> > wrote:
>> >
>> >>
>> >> G'day,
>> >>
>> >> There are a few variables to sort out but the basics are as
> follows:
>> >>
>> >> ww hull and decks and bulkheads area 6 sq m/65 sq'
>> >> lw hull and decks and bulkheads 14 sq m/150 sq'
>> >> Beams 5 sq m/54 sq'
>> >> Booms 2 sq m/12 sq'
>> >> Rudders 4 sq m/24 sq'
>> >> Total 31 sq m/335 sq' all of which are 5mm/0.2" core (timber or
>> > foam)
>> >> with 300 gsm/9 ounce glass each side of the foam, 200 gsm/6 ounce
>> > uni
>> >> glass each side of the timber
>> >> The beams also have 3 kgs/6.6 lbs of carbon tow, or 5 kgs/11
> pounds
>> > of
>> >> uni glass, the booms 1kg/2.2 lbs of tow or 2kgs/4.4 lbs of uni
> glass
>> >> and the rudders 3 kgs/6.6 lbs of carbon tow.
>> >> The masts are 2 kgs/4.4 lbs of 300 gsm/9 ounce glass and 4
> kgs.8.8
>> > lbs
>> >> of carbon tow.
>> >>
>> >> Depending on where you are, carbon tow is $45/kg or $21/lb. I can
>> > get
>> >> the other prices if you are in Australia, or contact your local
>> >> supplier.
>> >>
>> >> The above does not include wastage, filling and gluing powders,
>> > paint,
>> >> tramp, tent, sails, sheets or deck gear. I can give you specifics
>> > on
>> >> these once I know exactly what you want to build.
>> >>
>> >> Any questions, please let me know.
>> >>
>> >> Regards,
>> >>
>> >> Rob
>> >>
>> >>
>> >>
>> >>
>> >>
>> >> On Thu, Jul 3, 2008 at 4:47 PM, chesterdave <chesterdave@> wrote:
>> >> > Hi everyone, Ive been interested in the camping version of the
>> >> > elementarry for quite some time and Im wondering if anyone has
> a
>> > basic
>> >> > knowledge of how much materials would be needed to build one.
> Any
>> > help
>> >> > would be greatly appreciated,
>> >> > DAVE
>> >> >
>> >> >
>> >>
>> >
>> >
>>
>
>

Hey Rob,
   I'm from Ocean Shores, just north of Byron Bay so a delivery price
would be good. As for the mast, what would you recomend? Is it
possible to build a wing mast at home? Is this included in the plans?
Again thanks for all your help,
  DAVE




--- In harryproa@..., "Rob Denney" <harryproa@...>
wrote:
>
> G'day,
>
> No problem using foam, nor using the Farrier method, except it is
very
> time consuming to prepare (you virtually strip plank half a hull),
to
> build (lots of screws, some heating of panels) and to complete (lots
> of fairing as the foam distorts as well as bends).   The windward
hull
> deck is flat, so there is not much point in using the planked foam
> method there.  If you want the lee hull to have rounded decks
instead
> of flat ones with big edge radii then stripping is the way to get
> this.
>
> A single rig is no problem, Youri has put an 18 sq m on the race
> version.   I think this is as big as you would want on the camper.
> Are you having a wing mast?
>
> 15 sheets is 43 sq m, should be enough (I missed out the hard bit of
> trampoline, and there may be a bit more in the hatch than I allowed
> for.
>
> Happy to get you the materials.  I will get a quote on Monday and
let
> you know.  Where abouts in northern NSW?    Will you pick it up from
> Sydney, or shall I get a delivery price?
>
> regards,
>
> Rob
>
>
>
>
> On Fri, Jul 4, 2008 at 5:47 PM, chesterdave <chesterdave@...> wrote:
> > Hi Rob,
> > Thanks for the prompt reply, so the general idea flying round
> > in my head is for a foam version of the camping elementarry,
> > Is it possible to build using the vertical strip method in a
female
> > mould like the farrier trimarans?
> > I would like to do some solo sailing so a single mast is probably
> > the better idea, so the schooner rig has i think 22 sq m of sail
and
> > the single rig 11, can a single rig of say 15 - 18 sq m of sail be
> > used?
> > I've done some (VERY ROUGH) calculations and decided 15 sheets of
> > 2400 x 1200 foam would be plenty, does this sound right?
> > Is it possible to source the materials from you? I live in
northern
> > NSW by the way, again thanks for the prompt reply to my previous
> > post, its nice to comunicate with a designer that actually wants
to
> > help
> >
> > Thanks,
> > DAVE
> >
> >
> > --- In harryproa@..., "Rob Denney" <harryproa@>
> > wrote:
> >
> >>
> >> G'day,
> >>
> >> There are a few variables to sort out but the basics are as
follows:
> >>
> >> ww hull and decks and bulkheads area 6 sq m/65 sq'
> >> lw hull and decks and bulkheads 14 sq m/150 sq'
> >> Beams 5 sq m/54 sq'
> >> Booms 2 sq m/12 sq'
> >> Rudders 4 sq m/24 sq'
> >> Total 31 sq m/335 sq' all of which are 5mm/0.2" core (timber or
> > foam)
> >> with 300 gsm/9 ounce glass each side of the foam, 200 gsm/6 ounce
> > uni
> >> glass each side of the timber
> >> The beams also have 3 kgs/6.6 lbs of carbon tow, or 5 kgs/11
pounds
> > of
> >> uni glass, the booms 1kg/2.2 lbs of tow or 2kgs/4.4 lbs of uni
glass
> >> and the rudders 3 kgs/6.6 lbs of carbon tow.
> >> The masts are 2 kgs/4.4 lbs of 300 gsm/9 ounce glass and 4
kgs.8.8
> > lbs
> >> of carbon tow.
> >>
> >> Depending on where you are, carbon tow is $45/kg or $21/lb. I can
> > get
> >> the other prices if you are in Australia, or contact your local
> >> supplier.
> >>
> >> The above does not include wastage, filling and gluing powders,
> > paint,
> >> tramp, tent, sails, sheets or deck gear. I can give you specifics
> > on
> >> these once I know exactly what you want to build.
> >>
> >> Any questions, please let me know.
> >>
> >> Regards,
> >>
> >> Rob
> >>
> >>
> >>
> >>
> >>
> >> On Thu, Jul 3, 2008 at 4:47 PM, chesterdave <chesterdave@> wrote:
> >> > Hi everyone, Ive been interested in the camping version of the
> >> > elementarry for quite some time and Im wondering if anyone has
a
> > basic
> >> > knowledge of how much materials would be needed to build one.
Any
> > help
> >> > would be greatly appreciated,
> >> > DAVE
> >> >
> >> >
> >>
> >
> >
>

-I think one of the points is that it reduces compression loads on the
mast to have the catch at the top.
Also, there are some pretty low stretch rope nowadays without the
weight, and are easier to attach than wire
  Robert-- In harryproa@..., "petermirow"
<petermirow@...> wrote:
>
> Sorry if I jump in, and I have been following this thread only as
> much as possible.
> But, all boats I've sailed on, big and small, use wire for halyards.
> There is no strech in wire. Doesn't that solve the problem?
> Again, sorry if I'm talking rubbish.
> Cheers,
> Peter
>
> --- In harryproa@..., "k_s_oneill" <K_S_ONeill@>
> wrote:
> >
> > --- In harryproa@..., "cruising.sailor" <tom@> wrote:
> > >
> > > Kevin,
> > >
> > > I'm not getting how you get the halyard to be locked and then
> > > unlocked. Could you say more about that, pleeese?
> > >
> > >  - any more detailed pix might help too ;)
> > >
> > > Thanks a lot,
> > > TomH
> >
> > Hi
> >
> > I'm not sure this will tell you any more than you already know:
> >
> > http://wikiproa.pbwiki.com/f/spinlock%20at%20masthead%20test%
> 20fit.JPG
> >
> > That was a test fit with stuff just ziptied on, to see if I could
> > indeed cleat and uncleat the things from the other end of the mast.
> > It works fine.
> >
> > They're small spinlock cleats, you cleat them by pulling straight
> down
> > the mast, and uncleat them by pulling away from the mast at an
> angle.
> >  When they're uncleated they run very free, when cleated they grip
> > very securely, I haven't had one slip at all yet that I can tell, in
> > any application.  I had these two lying around from a previous rig
> and
> > was worried about what halyard tension would do to my somewhat
> limber
> > masts, so I tried this out.  They're the old style, Spinlock has
> some
> > newer sexy looking models out, so you may be able to pick some like
> > these up on sale if you look around.
> >
> > Kevin
> >
>

G'day,

No problem using foam, nor using the Farrier method, except it is very
time consuming to prepare (you virtually strip plank half a hull), to
build (lots of screws, some heating of panels) and to complete (lots
of fairing as the foam distorts as well as bends).   The windward hull
deck is flat, so there is not much point in using the planked foam
method there.  If you want the lee hull to have rounded decks instead
of flat ones with big edge radii then stripping is the way to get
this.

A single rig is no problem, Youri has put an 18 sq m on the race
version.   I think this is as big as you would want on the camper.
Are you having a wing mast?

15 sheets is 43 sq m, should be enough (I missed out the hard bit of
trampoline, and there may be a bit more in the hatch than I allowed
for.

Happy to get you the materials.  I will get a quote on Monday and let
you know.  Where abouts in northern NSW?    Will you pick it up from
Sydney, or shall I get a delivery price?

regards,

Rob




On Fri, Jul 4, 2008 at 5:47 PM, chesterdave <chesterdave@...> wrote:
> Hi Rob,
> Thanks for the prompt reply, so the general idea flying round
> in my head is for a foam version of the camping elementarry,
> Is it possible to build using the vertical strip method in a female
> mould like the farrier trimarans?
> I would like to do some solo sailing so a single mast is probably
> the better idea, so the schooner rig has i think 22 sq m of sail and
> the single rig 11, can a single rig of say 15 - 18 sq m of sail be
> used?
> I've done some (VERY ROUGH) calculations and decided 15 sheets of
> 2400 x 1200 foam would be plenty, does this sound right?
> Is it possible to source the materials from you? I live in northern
> NSW by the way, again thanks for the prompt reply to my previous
> post, its nice to comunicate with a designer that actually wants to
> help
>
> Thanks,
> DAVE
>
>
> --- In harryproa@..., "Rob Denney" <harryproa@...>
> wrote:
>
>>
>> G'day,
>>
>> There are a few variables to sort out but the basics are as follows:
>>
>> ww hull and decks and bulkheads area 6 sq m/65 sq'
>> lw hull and decks and bulkheads 14 sq m/150 sq'
>> Beams 5 sq m/54 sq'
>> Booms 2 sq m/12 sq'
>> Rudders 4 sq m/24 sq'
>> Total 31 sq m/335 sq' all of which are 5mm/0.2" core (timber or
> foam)
>> with 300 gsm/9 ounce glass each side of the foam, 200 gsm/6 ounce
> uni
>> glass each side of the timber
>> The beams also have 3 kgs/6.6 lbs of carbon tow, or 5 kgs/11 pounds
> of
>> uni glass, the booms 1kg/2.2 lbs of tow or 2kgs/4.4 lbs of uni glass
>> and the rudders 3 kgs/6.6 lbs of carbon tow.
>> The masts are 2 kgs/4.4 lbs of 300 gsm/9 ounce glass and 4 kgs.8.8
> lbs
>> of carbon tow.
>>
>> Depending on where you are, carbon tow is $45/kg or $21/lb. I can
> get
>> the other prices if you are in Australia, or contact your local
>> supplier.
>>
>> The above does not include wastage, filling and gluing powders,
> paint,
>> tramp, tent, sails, sheets or deck gear. I can give you specifics
> on
>> these once I know exactly what you want to build.
>>
>> Any questions, please let me know.
>>
>> Regards,
>>
>> Rob
>>
>>
>>
>>
>>
>> On Thu, Jul 3, 2008 at 4:47 PM, chesterdave <chesterdave@...> wrote:
>> > Hi everyone, Ive been interested in the camping version of the
>> > elementarry for quite some time and Im wondering if anyone has a
> basic
>> > knowledge of how much materials would be needed to build one. Any
> help
>> > would be greatly appreciated,
>> > DAVE
>> >
>> >
>>
>
>

Sorry if I jump in, and I have been following this thread only as
much as possible.
But, all boats I've sailed on, big and small, use wire for halyards.
There is no strech in wire. Doesn't that solve the problem?
Again, sorry if I'm talking rubbish.
Cheers,
Peter

--- In harryproa@..., "k_s_oneill" <K_S_ONeill@...>
wrote:
>
> --- In harryproa@..., "cruising.sailor" <tom@> wrote:
> >
> > Kevin,
> >
> > I'm not getting how you get the halyard to be locked and then
> > unlocked. Could you say more about that, pleeese?
> >
> >  - any more detailed pix might help too ;)
> >
> > Thanks a lot,
> > TomH
>
> Hi
>
> I'm not sure this will tell you any more than you already know:
>
> http://wikiproa.pbwiki.com/f/spinlock%20at%20masthead%20test%
20fit.JPG
>
> That was a test fit with stuff just ziptied on, to see if I could
> indeed cleat and uncleat the things from the other end of the mast.
> It works fine.
>
> They're small spinlock cleats, you cleat them by pulling straight
down
> the mast, and uncleat them by pulling away from the mast at an
angle.
>  When they're uncleated they run very free, when cleated they grip
> very securely, I haven't had one slip at all yet that I can tell, in
> any application.  I had these two lying around from a previous rig
and
> was worried about what halyard tension would do to my somewhat
limber
> masts, so I tried this out.  They're the old style, Spinlock has
some
> newer sexy looking models out, so you may be able to pick some like
> these up on sale if you look around.
>
> Kevin
>

Great model and video, Todd.
What is the scale of the model?
Cheers,
Peter



--- In harryproa@..., "tsstproa" <bitme1234@...> wrote:
>
>  Here are two clips of a shunt with square harry flat bottom hulls.
> Windward hull with a little rock and leeward with non. The winds
are
> from 8 to 12 mph and stronger. Took head sail off of easy rig due
to
> being over power due to mast flex. The rudders are asymmetrical and
> would stall at lower speeds when wind gusts would hit from stright
> broad side after a shunt geting cought in irons drifting down wind
> side ways . But when moving foward with flow over the rudders they
> would hook up, with a slight weather helm needing input from
control
> stick to keep from heading up. Deffinately not hands off steering.
> The boat would fall off the wind better with only rear rudder down
> and with head sail on but winds where to strong for rig set up. In
> the process of redoing rig and rudder arrangment. Shorter main sail
> with same sail area but with a more square top and battens with a
> stiffer mast.
>
> Deffinately fast with head sail on a close reach. Surpisingly even
> to layperson like my wife. But a bit out of control and over
powered.
>
> http://www.youtube.com/watch?v=DaP977ioHao
> http://www.youtube.com/watch?v=jkCTjpOosyk&feature=user
>
> Todd
>

Gardner,

  In response to you questions.  4KW is the expected consumption of
8-10KW electric lumbering at less than hull speed for 2.5 hours.
Might be worse than that (6-7KW consumed) but it was an example of
the HUGE disparity between energy stored in a battery and anergy
capability of hydrocarbon fuels.  If you are pushing a Visioanarry
at hull speed, you will need at least a total of 10KW.  You might
end up a little less than hull speed depending on how "big" a
Visionarry.  Takes 20KW to move an African cats Fastcat (14,000lb
dispacement)at 8.5 knots.  You should have about half that mass.

That testing was done in flat water.  Hull speed is only a flat
water measure, if your design windage is bad then running upwind
you may get 1-2 knots.  Rare Bird used (2) 15 HP outboards.  10KW
is only getting you the same "max" thrust as (1) Honda.  I don't
find that yet to a handicap, just know I won't be busting 9 knots !
Don't be fooled by advertising a 4KW = 10-15HP Ouboard.  It's not
true "except" when the outboard is moving you at 3-4 knots, well
below it's optimum torque curve of the Honda.  Speed above that and
15HP outboard is more efficient and has more thrust. Top end thrust
of a 15 HP Honda is more like a 10KW electric.  As a side note you
can over-power a electric for brief periods until the motor or
control overheats.  So that's when you can get 15HP equivalent out of
4KW motor, just can only run minutes or perhaps seconds at that load.

You can split up 10KW needs anyway you want (2) 4-5KW is fine.  Don't
worry electric pods will eventually leak thru the bearing seals.
You won't ruin them if they do leak.  In acuality they will have
some water in them due to internal condensation.  That little water
gets cooked out as it runs a little.  If the POD is stored in a
position out of the water then seals may never have to be replaced.
Otherwise the pod and it's connecting arm with wires is the only
part submerged, all the rest is housed in a separate external box
and generally water tight.

The biggest hassle is how much electrical energy to store, and how
to do it safest and cheapest.

Regards,
JT

--- In harryproa@..., "Gardner Pomper" <gardner@...>
wrote:
>
> Hi,
>
> I think you have summed up random findings of mine very well. I
have a
> couple questions. You mention that your monohull would require a 4KW
> electric, but you sized a genset at 10KW continuous. Were you
intending that
> there are 2 4KW electrics on a Visionarry sized boat?
>
> I am on the fence with the outboard vs the diesel genset. I want 2
motors
> for the maneuverability in tight quarters, as well as the
redundancy. I had
> a small cat with dual outboards and they worked well for motoring,
but were
> lousy at charging the batteries. We had solar panels for that, but
the sun
> didn't always shine. I *really* wanted a small generator for battery
> charging as well.
>
> Would you mine resumarrizing your findings to compare a dual
outboard system
> (15Hp each), plus a small genset for battery charging, vs a diesel
genset
> with 2 4KW electrics? I was thinking that those two systems would
be close
> in weight, but unfortunately not in cost.
>
> My main concern about a dual outboard solution is that I don't see
an
> adequate way of getting the leeward outboard far enough away from
the water
> that it will not get wet when hard sailing. Even when flipped up, I
would
> think that there will be a LOT of water intrusion into the head.
Would an
> electric motor in a pod be more waterproof, or easier to shield?
>
> Thanks for the summary. It is often surprising how complicated a
sailboat
> gets once you want it to do something more than just sail.
>
> - Gardner
>
>
> On Fri, Jul 4, 2008 at 11:27 AM, jjtctaylor <jtaylor412@...> wrote:
>
> >   In my quest for ideal auxiliary propulsion for our beloved
cruising
> > proas, I have hit a snag. The proverbial weight spiral has begun.
> > Today's technology has left us with gas outboards, hydraulic, and
> > electrical. Outboards have no comparison in weight to thrust
> > ratio. All Harry's and smaller would benefit greatly from that
> > choice. For Visionarry's and larger which will have long motoring
> > requirements the choice is more murky.
> >
> > Outboards can run for extended periods but do need some degree of
> > care maintenance. Have to carry a more volatile fuel and prop can
> > run into cavitation issues in rough seas due to limited leg
length.
> >
> > The most elegant option is electric pod in various installation
> > methods. Now comes the bad news. While the electric pod isn't
> > heavy, all that supporting power source is. As mentioned above for
> > outboards hyrdrocarbon fuel has much more energy/weight ratio than
> > anything else readily available.
> >
> > Case in point, my 36 foot monohull got about 16 miles per gallon
at 6
> > knots. An electric would consume about 4KW. To store 4KW, you
need 8-
> > 10 KW of batteries. That's because you should not discharge
> > batteries beyond 50% capacity or the life cycle rate drops
> > significantly (1500 cycles --> 300 more or less) and batteries
once
> > used do not return to their original 100% capacity due to
sulfation.
> > Sulfation is the coating of the lead plates by sulfur crystals
> > leaching out of the sulfuric acid electrolyte. The crystals
prevent
> > the transfer of charge from the lead plates, thus we are always
left
> > with only 92-98% of the original capacity.
> >
> > So what we have is the difference of 7 pounds for hydrocarbon
fuels
> > versus 600 pounds for 8KW battery capacity. There are many new
> > technologies on the horizon for batteries, ultracapacitors, etc.
but
> > nothing is coming near term for the boating industry.
> >
> > Only technologies that could be options, available for over 20
years
> > are NiMh and Lithium-ion. Both are outrageously expensive,
typically
> > (4) times the cost of lead-acid types. NiMh are available from
> > Nilar, but you are on your own as no one supports or warrants them
> > for marine application. Nimh also has high self-discharge rates
of 1-
> > 3% per day, so would require dedicated solar panels to keep them
> > charged. Lithium-ion technology is reducing their probability to
> > catch fire by adding metal alloys to the lithium to handle high
> > current and each cell has a mini-pc attached to manage charge and
> > discharge rates. See Lifebatt, Valence, and A123 to name a few
> > suppliers all migrating to this new direction for Lithium-ion.
> > Despite the high cost these technologies do double the storage
> > capacity/weight ratio.
> >
> > So for battery technology we have a real boat anchor in terms of
> > energy storage capacity. For a Visionarry sized craft, 8-10KW
motor
> > would be satisfactory for hull speed. Battery capacity would
dictate
> > around 14KW for 40 minutes at full throttle, or 800 pounds. If you
> > have deep cash pockets Lithium-ion batteries are only 400 pounds.
So
> > what happens when battery capacity is gone and no wind to regen.
> > Then we have to rely on a generator.
> >
> > Generator has to be rated to provide some satisfactory cruising
speed
> > AND some reserve to recharge batteries. For a Visionarry that
would
> > be a 10KW. Generators run to full capacity are not intended as
> > propulsion engines and will overheat . Thus they have to be de-
rated
> > to run less than max output. In my case I use a Volvo D1-20
engine,
> > 18HP to the output shaft (13.5KW) and rated down to 10KW
continuous.
> > All that weighs 360 pounds. A whole lot more than a 15HP Honda
> > outboard. Add to that another 80 pounds of AC-DC battery chargers,
> > DC-DC chargers, breaker boxes and cables.
> >
> > The expense of it all is a killer too. $16000 genset, $2400
> > batteries and $8000 electric motor. Buy a few Honda's.
> >
> > As I have mentioned before you can do with less power or less run
> > time, but that compromise at some point becomes unsafe or
impractical
> > to deal with the elements or sea conditions. In many ways the
trade
> > off away from fossil fuels we are getting less for more. In total
my
> > boat looks to weigh out around 8000 lbs light and 10000 loaded,
which
> > is not where I wanted to be. Maybe someone on the forum has a
> > breakthrough we can all reapply. Adding over 1000 pounds to a boat
> > professed to be lighter and easier to build doesn't seem to be the
> > right direction.
> >
> > Regards,
> > JT
> >
> >
> >
>

In my quest for ideal auxiliary propulsion for our beloved cruising
proas, I have hit a snag.  The proverbial weight spiral has begun.
Today's technology has left us with gas outboards, hydraulic, and
electrical.  Outboards have no comparison in weight to thrust
ratio.   All Harry's and smaller would benefit greatly from that
choice.   For Visionarry's and larger which will have long motoring
requirements the choice is more murky.

Outboards can run for extended periods but do need some degree of
care maintenance.   Have to carry a more volatile fuel and prop can
run into cavitation issues in rough seas due to limited leg length.

The most elegant option is electric pod in various installation
methods.  Now comes the bad news.  While the electric pod isn't
heavy, all that supporting power source is.   As mentioned above for
outboards hyrdrocarbon fuel has much more energy/weight ratio than
anything else readily available.

Case in point, my 36 foot monohull got about 16 miles per gallon at 6
knots. An electric would consume about 4KW.  To store 4KW, you need 8-
10 KW of batteries.  That's because you should not discharge
batteries beyond 50% capacity or the life cycle rate drops
significantly (1500 cycles --> 300 more or less)  and batteries once
used do not return to their original 100% capacity due to sulfation.
Sulfation is the coating of the lead plates by sulfur crystals
leaching out of the sulfuric acid electrolyte.  The crystals prevent
the transfer of charge from the lead plates, thus we are always left
with only 92-98% of the original capacity.

So what we have is the difference of 7 pounds for hydrocarbon fuels
versus 600 pounds for 8KW battery capacity.  There are many new
technologies on the horizon for batteries, ultracapacitors, etc.  but
nothing is coming near term for the boating industry.

Only technologies that could be options, available for over 20 years
are NiMh and Lithium-ion.  Both are outrageously expensive, typically
(4) times the cost of lead-acid types.  NiMh are available from
Nilar, but you are on your own as no one supports or warrants them
for marine application.  Nimh also has high self-discharge rates of 1-
3% per day, so would require dedicated solar panels to keep them
charged.  Lithium-ion technology is reducing their probability to
catch fire by adding metal alloys to the lithium to handle high
current and each cell has a mini-pc attached to manage charge and
discharge rates.  See Lifebatt, Valence, and A123 to name a few
suppliers all migrating to this new direction for Lithium-ion.
Despite the high cost these technologies do double the storage
capacity/weight ratio.

So for battery technology we have a real boat anchor in terms of
energy storage capacity.  For a Visionarry sized craft, 8-10KW motor
would be satisfactory for hull speed.  Battery capacity would dictate
around 14KW for 40 minutes at full throttle, or 800 pounds.  If you
have deep cash pockets Lithium-ion batteries are only 400 pounds.  So
what happens when battery capacity is gone and no wind to regen.
Then we have to rely on a generator.

Generator has to be rated to provide some satisfactory cruising speed
AND some reserve to recharge batteries.  For a Visionarry that would
be a 10KW.  Generators run to full capacity are not intended as
propulsion engines and will overheat .  Thus they have to be de-rated
to run less than max output.  In my case I use a Volvo D1-20 engine,
18HP to the output shaft (13.5KW) and rated down to 10KW continuous.
All that weighs 360 pounds.  A whole lot more than a 15HP Honda
outboard.  Add to that another 80 pounds of AC-DC battery chargers,
DC-DC chargers, breaker boxes and cables.

The expense of it all is a killer too.  $16000 genset, $2400
batteries and $8000 electric motor.  Buy a few Honda's.

As I have mentioned before you can do with less power or less run
time, but that compromise at some point becomes unsafe or impractical
to deal with the elements or sea conditions.  In many ways the trade
off away from fossil fuels we are getting less for more.  In total my
boat looks to weigh out around 8000 lbs light and 10000 loaded, which
is not where I wanted to be.  Maybe someone on the forum has a
breakthrough we can all reapply.  Adding over 1000 pounds to a boat
professed to be lighter and easier to build doesn't seem to be the
right direction.

Regards,
JT

--Quote from Nida core site

'Again a thermoplastic product Is easily thermoformed:

In an oven, in 3d mold, at less than 100°C (212°F), NIDA-CORE softens
and under a very light pressure it very easily takes the required shape. '

I reckon if you get to 60-70C it should be behave itself. even 50C
should make it a bit safer to bend. A fan heater through the guts
could bring it pretty close.




- In harryproa@..., "Robert" <cateran1949@...> wrote:
>
> http://www.nida-core.com/english/nidaprod_honeyinfo_working.htm
>
> Polyprop melts at 160, scrim at 240, hot stamping is done at 200.
> probably 40 degree useful range for the stamp
>
>
>
>
> --- In harryproa@..., "Rob Denney" <harryproa@> wrote:
> >
> > G'day,
> > Can't find it on the Nida web page, but the honeycomb cells are a bit
> > lower melting point than the felt scrim.  Problem with too much heat,
> > if you over heat the cells, the felt melts and there will be no bond.
> > I have used bog on the deck and the hull, adds less than half a kg,
> > but is a pain to do.  Hull came out pretty well, deck is curing at the
> > moment.  Will bend the hull (slowly!) over the weekend.
> >
> > regards,
> >
> > Rob
> >
> > On Fri, Jul 4, 2008 at 2:15 AM, captian_rapscallion
> > <captian_rapscallion@> wrote:
> > > I think polycore is polypropylene,which usually melts around
160C, to
> > > get it bendable maybe 120-140 C?
> > >
> > > --- In harryproa@..., "Rob Denney" <harryproa@>
wrote:
> > >>
> > >> G'day,
> > >>
> > >> On Wed, Jul 2, 2008 at 2:03 PM, Robert <cateran1949@> wrote:
> > >> >
> > >> > G'day Rob,
> > >> > -To give you someone else to swear at for stating the obvious
with
> > >> > 20/20 hindsight from my armchair.
> > >> > Extra bog or extra glass to avoid the centre V.
> > >>
> > >> Would need to be quite a bit of extra glass (basalt, actually)
as it
> > >> is only 200 gsm. Bog may have done it, but it introduces another
> > >> variable.
> > >>
> > >> >
> > >> > Can't see that a
> > >> > shallow V is a problem
> > >>
> > >> It's not, but the middle 50% of the boat is glassed all the way
> across
> > >> and only the middle 25% has the join, so the section is a V between
> > >> two semi circles, which is. It was also not very shallow.
> > >>
> > >> > What was the ambient temperature during this run compared to the
> > >> > previous? A blow heater through the guts may help. Possibly
> some thin
> > >> > cheap ply on the outside and inside to keep the bending more even
> > >>
> > >> 20C. Some heat may help, I will try it tomorrow when I bend
this one.
> > >> I am also using 4mm Polycore for the 3m hull instead of 6mm.
> > >> >
> > >> > To avoid stretch when squashing, a long as possible heat
conductive
> > >> > piece of stiff flat metal-possibly box section insulated on three
> > >> > sides, so that you can blow heat down the middle. It then gets
> pressed
> > >> > all at once rather than squashing it little by little- the
process
> > >> > used in spinning and beating metals.
> > >>
> > >> Needs to be seriously hot. I had the wife's clothes iron on
full heat
> > >> and even then it was not a quick operation. Bog on the edges works
> > >> (but not if it is vacuumed) or it would not be too difficult to
> make a
> > >> bog bevel. On the bigger boats, could put a roll of uni or tow
along
> > >> the edge to make the step.
> > >>
> > >> > No need to make any comments about slopping resin where it is not
> > >> > needed;>(
> > >>
> > >> Bloody stupid sums it up pretty well.
> > >>
> > >> > Thanks for making the mistakes so we don't have to make as many
> > >>
> > >> My pleasure.
> > >>
> > >> regards,
> > >>
> > >> Rob
> > >> > Robert
> > >> >
> > >> > -- In harryproa@..., "Rob Denney" <harryproa@>
> wrote:
> > >> > >
> > >> > > G'day,
> > >> > >
> > >> > > Folded up the ww harriette hull today. Did not go well. Mostly
> > >> > because I
> > >> > > rushed it. The centre piece folded beautifully, although it
> took a
> > >> > bit more
> > >> > > effort than I thought it would. I was concentrating on the
> > > middle and
> > >> > > thought the ends would be following suit. They weren't. The
> > >> > Polycore did
> > >> > > not bend evenly on either side iof the centreline,
resulting in a
> > >> > mess. At
> > >> > > one end this was caused by some spilt resin stiffening one
> side more
> > >> > than
> > >> > > the other, but at the other it just bent crooked, which is a
> worry.
> > >> > >
> > >> > > The centre section had a fore and aft join along the middle
> > > (trying to
> > >> > > minimise material use) which bent as a V instead of a
semicircle
> > >> > like the
> > >> > > rest of it. I also tried ironing the Polycore to taper the
edges,
> > >> > as per
> > >> > > the NidaPlast site. It worked, but stretched the material
on the
> > >> > underside
> > >> > > so it ended up as a wavy edge which needed to be filled.
This had
> > >> > not shown
> > >> > > up on the short pieces I had experimented on.
> > >> > >
> > >> > > Bit disappointing, but the lessons learnt are:
> > >> > > 1) Keep resin off unglassed areas
> > >> > > 2) No fore and aft joins in areas to be bent
> > >> > > 3) Lock the centreline to the table before bending. I used
a long
> > >> > straight
> > >> > > edge clamoped to the table for the experiments, completely
forgot
> > >> > this time.
> > >> > > 4) Slow bending is even bending. I suspect foam would bend more
> > >> > uniformly,
> > >> > > but would have to be even slower to stop it breaking.
> > >> > >
> > >> > > So, some serious abuse of me by me, some stroppy responses to
> > >> > various forums
> > >> > > (better pressure relief valve than kicking the cat or
shouting at
> > >> > the wife
> > >> > > and kid) and I am trying again today.
> > >> > >
> > >> > > regards,
> > >> > >
> > >> > > Rob
> > >> > >
> > >> >
> > >> >
> > >>
> > >
> > >
> >
>

http://www.nida-core.com/english/nidaprod_honeyinfo_working.htm

Polyprop melts at 160, scrim at 240, hot stamping is done at 200.
probably 40 degree useful range for the stamp




--- In harryproa@..., "Rob Denney" <harryproa@...> wrote:
>
> G'day,
> Can't find it on the Nida web page, but the honeycomb cells are a bit
> lower melting point than the felt scrim.  Problem with too much heat,
> if you over heat the cells, the felt melts and there will be no bond.
> I have used bog on the deck and the hull, adds less than half a kg,
> but is a pain to do.  Hull came out pretty well, deck is curing at the
> moment.  Will bend the hull (slowly!) over the weekend.
>
> regards,
>
> Rob
>
> On Fri, Jul 4, 2008 at 2:15 AM, captian_rapscallion
> <captian_rapscallion@...> wrote:
> > I think polycore is polypropylene,which usually melts around 160C, to
> > get it bendable maybe 120-140 C?
> >
> > --- In harryproa@..., "Rob Denney" <harryproa@> wrote:
> >>
> >> G'day,
> >>
> >> On Wed, Jul 2, 2008 at 2:03 PM, Robert <cateran1949@> wrote:
> >> >
> >> > G'day Rob,
> >> > -To give you someone else to swear at for stating the obvious with
> >> > 20/20 hindsight from my armchair.
> >> > Extra bog or extra glass to avoid the centre V.
> >>
> >> Would need to be quite a bit of extra glass (basalt, actually) as it
> >> is only 200 gsm. Bog may have done it, but it introduces another
> >> variable.
> >>
> >> >
> >> > Can't see that a
> >> > shallow V is a problem
> >>
> >> It's not, but the middle 50% of the boat is glassed all the way
across
> >> and only the middle 25% has the join, so the section is a V between
> >> two semi circles, which is. It was also not very shallow.
> >>
> >> > What was the ambient temperature during this run compared to the
> >> > previous? A blow heater through the guts may help. Possibly
some thin
> >> > cheap ply on the outside and inside to keep the bending more even
> >>
> >> 20C. Some heat may help, I will try it tomorrow when I bend this one.
> >> I am also using 4mm Polycore for the 3m hull instead of 6mm.
> >> >
> >> > To avoid stretch when squashing, a long as possible heat conductive
> >> > piece of stiff flat metal-possibly box section insulated on three
> >> > sides, so that you can blow heat down the middle. It then gets
pressed
> >> > all at once rather than squashing it little by little- the process
> >> > used in spinning and beating metals.
> >>
> >> Needs to be seriously hot. I had the wife's clothes iron on full heat
> >> and even then it was not a quick operation. Bog on the edges works
> >> (but not if it is vacuumed) or it would not be too difficult to
make a
> >> bog bevel. On the bigger boats, could put a roll of uni or tow along
> >> the edge to make the step.
> >>
> >> > No need to make any comments about slopping resin where it is not
> >> > needed;>(
> >>
> >> Bloody stupid sums it up pretty well.
> >>
> >> > Thanks for making the mistakes so we don't have to make as many
> >>
> >> My pleasure.
> >>
> >> regards,
> >>
> >> Rob
> >> > Robert
> >> >
> >> > -- In harryproa@..., "Rob Denney" <harryproa@>
wrote:
> >> > >
> >> > > G'day,
> >> > >
> >> > > Folded up the ww harriette hull today. Did not go well. Mostly
> >> > because I
> >> > > rushed it. The centre piece folded beautifully, although it
took a
> >> > bit more
> >> > > effort than I thought it would. I was concentrating on the
> > middle and
> >> > > thought the ends would be following suit. They weren't. The
> >> > Polycore did
> >> > > not bend evenly on either side iof the centreline, resulting in a
> >> > mess. At
> >> > > one end this was caused by some spilt resin stiffening one
side more
> >> > than
> >> > > the other, but at the other it just bent crooked, which is a
worry.
> >> > >
> >> > > The centre section had a fore and aft join along the middle
> > (trying to
> >> > > minimise material use) which bent as a V instead of a semicircle
> >> > like the
> >> > > rest of it. I also tried ironing the Polycore to taper the edges,
> >> > as per
> >> > > the NidaPlast site. It worked, but stretched the material on the
> >> > underside
> >> > > so it ended up as a wavy edge which needed to be filled. This had
> >> > not shown
> >> > > up on the short pieces I had experimented on.
> >> > >
> >> > > Bit disappointing, but the lessons learnt are:
> >> > > 1) Keep resin off unglassed areas
> >> > > 2) No fore and aft joins in areas to be bent
> >> > > 3) Lock the centreline to the table before bending. I used a long
> >> > straight
> >> > > edge clamoped to the table for the experiments, completely forgot
> >> > this time.
> >> > > 4) Slow bending is even bending. I suspect foam would bend more
> >> > uniformly,
> >> > > but would have to be even slower to stop it breaking.
> >> > >
> >> > > So, some serious abuse of me by me, some stroppy responses to
> >> > various forums
> >> > > (better pressure relief valve than kicking the cat or shouting at
> >> > the wife
> >> > > and kid) and I am trying again today.
> >> > >
> >> > > regards,
> >> > >
> >> > > Rob
> >> > >
> >> >
> >> >
> >>
> >
> >
>

Hi Rob,
        Thanks for the prompt reply, so the general idea flying round
in my head is for a foam version of the camping elementarry,
  Is it possible to build using the vertical strip method in a female
mould like the farrier trimarans?
  I would like to do some solo sailing so a single mast is probably
the better idea, so the schooner rig has i think 22 sq m of sail and
the single rig 11, can a single rig of say 15 - 18 sq m of sail be
used?
  I've done some (VERY ROUGH) calculations and decided 15 sheets of
2400 x 1200 foam would be plenty, does this sound right?
  Is it possible to source the materials from you? I live in northern
NSW by the way, again thanks for the prompt reply to my previous
post, its nice to comunicate with a designer that actually wants to
help

Thanks,
        DAVE





--- In harryproa@..., "Rob Denney" <harryproa@...>
wrote:
>
> G'day,
>
> There are a few variables to sort out but the basics are as follows:
>
> ww hull and decks and bulkheads  area 6 sq m/65 sq'
> lw hull and decks and bulkheads 14 sq m/150 sq'
> Beams 5 sq m/54 sq'
> Booms 2 sq m/12 sq'
> Rudders 4 sq m/24 sq'
> Total 31 sq m/335 sq' all of which are 5mm/0.2" core (timber or
foam)
> with 300 gsm/9 ounce glass each side of the foam, 200 gsm/6 ounce
uni
> glass each side of the timber
> The beams also have 3 kgs/6.6 lbs of carbon tow, or 5 kgs/11 pounds
of
> uni glass, the booms 1kg/2.2 lbs of tow or 2kgs/4.4 lbs of uni glass
> and the rudders 3 kgs/6.6 lbs of carbon tow.
> The masts are 2 kgs/4.4 lbs of 300 gsm/9 ounce glass and 4 kgs.8.8
lbs
> of carbon tow.
>
> Depending on where you are, carbon tow is $45/kg or $21/lb.  I can
get
> the other prices if you are in Australia, or contact your local
> supplier.
>
> The above does not include wastage, filling and gluing powders,
paint,
> tramp, tent, sails, sheets or deck gear.  I can give you specifics
on
> these once I know exactly what you want to build.
>
> Any questions, please let me know.
>
> Regards,
>
> Rob
>
>
>
>
>
> On Thu, Jul 3, 2008 at 4:47 PM, chesterdave <chesterdave@...> wrote:
> > Hi everyone, Ive been interested in the camping version of the
> > elementarry for quite some time and Im wondering if anyone has a
basic
> > knowledge of how much materials would be needed to build one. Any
help
> > would be greatly appreciated,
> > DAVE
> >
> >
>

Thanks for you frank reporting of mistakes/problems as well as
milestones, Rob.  Your openness is a blessing to those of us who are
trying to learn...
This is my first post, but for some months I have been sitting down
the back of the class...

Regards,

Jeff

--- In harryproa@..., "Rob Denney" <harryproa@...> wrote:
>
> G'day,
> Can't find it on the Nida web page, but the honeycomb cells are a bit
> lower melting point than the felt scrim.  Problem with too much heat,
> if you over heat the cells, the felt melts and there will be no bond.
> I have used bog on the deck and the hull, adds less than half a kg,
> but is a pain to do.  Hull came out pretty well, deck is curing at the
> moment.  Will bend the hull (slowly!) over the weekend.
>
> regards,
>
> Rob
>
> On Fri, Jul 4, 2008 at 2:15 AM, captian_rapscallion
> <captian_rapscallion@...> wrote:
> > I think polycore is polypropylene,which usually melts around 160C, to
> > get it bendable maybe 120-140 C?
> >
> > --- In harryproa@..., "Rob Denney" <harryproa@> wrote:
> >>
> >> G'day,
> >>
> >> On Wed, Jul 2, 2008 at 2:03 PM, Robert <cateran1949@> wrote:
> >> >
> >> > G'day Rob,
> >> > -To give you someone else to swear at for stating the obvious with
> >> > 20/20 hindsight from my armchair.
> >> > Extra bog or extra glass to avoid the centre V.
> >>
> >> Would need to be quite a bit of extra glass (basalt, actually) as it
> >> is only 200 gsm. Bog may have done it, but it introduces another
> >> variable.
> >>
> >> >
> >> > Can't see that a
> >> > shallow V is a problem
> >>
> >> It's not, but the middle 50% of the boat is glassed all the way
across
> >> and only the middle 25% has the join, so the section is a V between
> >> two semi circles, which is. It was also not very shallow.
> >>
> >> > What was the ambient temperature during this run compared to the
> >> > previous? A blow heater through the guts may help. Possibly
some thin
> >> > cheap ply on the outside and inside to keep the bending more even
> >>
> >> 20C. Some heat may help, I will try it tomorrow when I bend this one.
> >> I am also using 4mm Polycore for the 3m hull instead of 6mm.
> >> >
> >> > To avoid stretch when squashing, a long as possible heat conductive
> >> > piece of stiff flat metal-possibly box section insulated on three
> >> > sides, so that you can blow heat down the middle. It then gets
pressed
> >> > all at once rather than squashing it little by little- the process
> >> > used in spinning and beating metals.
> >>
> >> Needs to be seriously hot. I had the wife's clothes iron on full heat
> >> and even then it was not a quick operation. Bog on the edges works
> >> (but not if it is vacuumed) or it would not be too difficult to
make a
> >> bog bevel. On the bigger boats, could put a roll of uni or tow along
> >> the edge to make the step.
> >>
> >> > No need to make any comments about slopping resin where it is not
> >> > needed;>(
> >>
> >> Bloody stupid sums it up pretty well.
> >>
> >> > Thanks for making the mistakes so we don't have to make as many
> >>
> >> My pleasure.
> >>
> >> regards,
> >>
> >> Rob
> >> > Robert
> >> >
> >> > -- In harryproa@..., "Rob Denney" <harryproa@>
wrote:
> >> > >
> >> > > G'day,
> >> > >
> >> > > Folded up the ww harriette hull today. Did not go well. Mostly
> >> > because I
> >> > > rushed it. The centre piece folded beautifully, although it
took a
> >> > bit more
> >> > > effort than I thought it would. I was concentrating on the
> > middle and
> >> > > thought the ends would be following suit. They weren't. The
> >> > Polycore did
> >> > > not bend evenly on either side iof the centreline, resulting in a
> >> > mess. At
> >> > > one end this was caused by some spilt resin stiffening one
side more
> >> > than
> >> > > the other, but at the other it just bent crooked, which is a
worry.
> >> > >
> >> > > The centre section had a fore and aft join along the middle
> > (trying to
> >> > > minimise material use) which bent as a V instead of a semicircle
> >> > like the
> >> > > rest of it. I also tried ironing the Polycore to taper the edges,
> >> > as per
> >> > > the NidaPlast site. It worked, but stretched the material on the
> >> > underside
> >> > > so it ended up as a wavy edge which needed to be filled. This had
> >> > not shown
> >> > > up on the short pieces I had experimented on.
> >> > >
> >> > > Bit disappointing, but the lessons learnt are:
> >> > > 1) Keep resin off unglassed areas
> >> > > 2) No fore and aft joins in areas to be bent
> >> > > 3) Lock the centreline to the table before bending. I used a long
> >> > straight
> >> > > edge clamoped to the table for the experiments, completely forgot
> >> > this time.
> >> > > 4) Slow bending is even bending. I suspect foam would bend more
> >> > uniformly,
> >> > > but would have to be even slower to stop it breaking.
> >> > >
> >> > > So, some serious abuse of me by me, some stroppy responses to
> >> > various forums
> >> > > (better pressure relief valve than kicking the cat or shouting at
> >> > the wife
> >> > > and kid) and I am trying again today.
> >> > >
> >> > > regards,
> >> > >
> >> > > Rob
> >> > >
> >> >
> >> >
> >>
> >
> >
>

G'day,
Can't find it on the Nida web page, but the honeycomb cells are a bit
lower melting point than the felt scrim.  Problem with too much heat,
if you over heat the cells, the felt melts and there will be no bond.
I have used bog on the deck and the hull, adds less than half a kg,
but is a pain to do.  Hull came out pretty well, deck is curing at the
moment.  Will bend the hull (slowly!) over the weekend.

regards,

Rob

On Fri, Jul 4, 2008 at 2:15 AM, captian_rapscallion
<captian_rapscallion@...> wrote:
> I think polycore is polypropylene,which usually melts around 160C, to
> get it bendable maybe 120-140 C?
>
> --- In harryproa@..., "Rob Denney" <harryproa@...> wrote:
>>
>> G'day,
>>
>> On Wed, Jul 2, 2008 at 2:03 PM, Robert <cateran1949@...> wrote:
>> >
>> > G'day Rob,
>> > -To give you someone else to swear at for stating the obvious with
>> > 20/20 hindsight from my armchair.
>> > Extra bog or extra glass to avoid the centre V.
>>
>> Would need to be quite a bit of extra glass (basalt, actually) as it
>> is only 200 gsm. Bog may have done it, but it introduces another
>> variable.
>>
>> >
>> > Can't see that a
>> > shallow V is a problem
>>
>> It's not, but the middle 50% of the boat is glassed all the way across
>> and only the middle 25% has the join, so the section is a V between
>> two semi circles, which is. It was also not very shallow.
>>
>> > What was the ambient temperature during this run compared to the
>> > previous? A blow heater through the guts may help. Possibly some thin
>> > cheap ply on the outside and inside to keep the bending more even
>>
>> 20C. Some heat may help, I will try it tomorrow when I bend this one.
>> I am also using 4mm Polycore for the 3m hull instead of 6mm.
>> >
>> > To avoid stretch when squashing, a long as possible heat conductive
>> > piece of stiff flat metal-possibly box section insulated on three
>> > sides, so that you can blow heat down the middle. It then gets pressed
>> > all at once rather than squashing it little by little- the process
>> > used in spinning and beating metals.
>>
>> Needs to be seriously hot. I had the wife's clothes iron on full heat
>> and even then it was not a quick operation. Bog on the edges works
>> (but not if it is vacuumed) or it would not be too difficult to make a
>> bog bevel. On the bigger boats, could put a roll of uni or tow along
>> the edge to make the step.
>>
>> > No need to make any comments about slopping resin where it is not
>> > needed;>(
>>
>> Bloody stupid sums it up pretty well.
>>
>> > Thanks for making the mistakes so we don't have to make as many
>>
>> My pleasure.
>>
>> regards,
>>
>> Rob
>> > Robert
>> >
>> > -- In harryproa@..., "Rob Denney" <harryproa@> wrote:
>> > >
>> > > G'day,
>> > >
>> > > Folded up the ww harriette hull today. Did not go well. Mostly
>> > because I
>> > > rushed it. The centre piece folded beautifully, although it took a
>> > bit more
>> > > effort than I thought it would. I was concentrating on the
> middle and
>> > > thought the ends would be following suit. They weren't. The
>> > Polycore did
>> > > not bend evenly on either side iof the centreline, resulting in a
>> > mess. At
>> > > one end this was caused by some spilt resin stiffening one side more
>> > than
>> > > the other, but at the other it just bent crooked, which is a worry.
>> > >
>> > > The centre section had a fore and aft join along the middle
> (trying to
>> > > minimise material use) which bent as a V instead of a semicircle
>> > like the
>> > > rest of it. I also tried ironing the Polycore to taper the edges,
>> > as per
>> > > the NidaPlast site. It worked, but stretched the material on the
>> > underside
>> > > so it ended up as a wavy edge which needed to be filled. This had
>> > not shown
>> > > up on the short pieces I had experimented on.
>> > >
>> > > Bit disappointing, but the lessons learnt are:
>> > > 1) Keep resin off unglassed areas
>> > > 2) No fore and aft joins in areas to be bent
>> > > 3) Lock the centreline to the table before bending. I used a long
>> > straight
>> > > edge clamoped to the table for the experiments, completely forgot
>> > this time.
>> > > 4) Slow bending is even bending. I suspect foam would bend more
>> > uniformly,
>> > > but would have to be even slower to stop it breaking.
>> > >
>> > > So, some serious abuse of me by me, some stroppy responses to
>> > various forums
>> > > (better pressure relief valve than kicking the cat or shouting at
>> > the wife
>> > > and kid) and I am trying again today.
>> > >
>> > > regards,
>> > >
>> > > Rob
>> > >
>> >
>> >
>>
>
>

Brilliant!  Look forward to the new rig and more consistent breeze.
Wuld it be ok to put some of these on the harryproa web page?

regards,

Rob

On Fri, Jul 4, 2008 at 6:15 AM, tsstproa <bitme1234@...> wrote:
> Here are two clips of a shunt with square harry flat bottom hulls.
> Windward hull with a little rock and leeward with non. The winds are
> from 8 to 12 mph and stronger. Took head sail off of easy rig due to
> being over power due to mast flex. The rudders are asymmetrical and
> would stall at lower speeds when wind gusts would hit from stright
> broad side after a shunt geting cought in irons drifting down wind
> side ways . But when moving foward with flow over the rudders they
> would hook up, with a slight weather helm needing input from control
> stick to keep from heading up. Deffinately not hands off steering.
> The boat would fall off the wind better with only rear rudder down
> and with head sail on but winds where to strong for rig set up. In
> the process of redoing rig and rudder arrangment. Shorter main sail
> with same sail area but with a more square top and battens with a
> stiffer mast.
>
> Deffinately fast with head sail on a close reach. Surpisingly even
> to layperson like my wife. But a bit out of control and over powered.
>
> http://www.youtube.com/watch?v=DaP977ioHao
> http://www.youtube.com/watch?v=jkCTjpOosyk&feature=user
>
> Todd
>
>

G'day,
This might be of interest.

regards,

Rob


---------- Forwarded message ----------
From: Steve Gubser/Ann Mathis <steve-o@...>
Date: Fri, Jul 4, 2008 at 5:37 AM
Subject: [multihull_boatbuilder] Resin INfusion in Houston
To: multihull_boatbuilder@yahoogroups.com


Hey Ya'll,

I should be infusing one of my 48' hulls in late July if anyone is
intersted in seeing it done. I will be laying out the reinforcements
July 12/13, setting up the infusion strategy around July 20th dates and
hopefully infusing the last weekend in July.

Let me know if you want to see any of the above.

Steve
Latitude Adjustment
48' KHSD catamaran
www.goyadi.com

Here are two clips of a shunt with square harry flat bottom hulls.
Windward hull with a little rock and leeward with non. The winds are
from 8 to 12 mph and stronger. Took head sail off of easy rig due to
being over power due to mast flex. The rudders are asymmetrical and
would stall at lower speeds when wind gusts would hit from stright
broad side after a shunt geting cought in irons drifting down wind
side ways . But when moving foward with flow over the rudders they
would hook up, with a slight weather helm needing input from control
stick to keep from heading up. Deffinately not hands off steering.
The boat would fall off the wind better with only rear rudder down
and with head sail on but winds where to strong for rig set up. In
the process of redoing rig and rudder arrangment. Shorter main sail
with same sail area but with a more square top and battens with a
stiffer mast.

Deffinately fast with head sail on a close reach. Surpisingly even
to layperson like my wife. But a bit out of control and over powered.

http://www.youtube.com/watch?v=DaP977ioHao
http://www.youtube.com/watch?v=jkCTjpOosyk&feature=user

Todd

I think polycore is polypropylene,which usually melts around 160C, to
get it bendable maybe 120-140 C?

--- In harryproa@..., "Rob Denney" <harryproa@...> wrote:
>
> G'day,
>
> On Wed, Jul 2, 2008 at 2:03 PM, Robert <cateran1949@...> wrote:
> >
> > G'day Rob,
> > -To give you someone else to swear at for stating the obvious with
> > 20/20 hindsight from my armchair.
> > Extra bog or extra glass to avoid the centre V.
>
> Would need to be quite a bit of extra glass (basalt, actually) as it
> is only 200 gsm.  Bog may have done it, but it introduces another
> variable.
>
> >
> > Can't see that a
> > shallow V is a problem
>
> It's not, but the middle 50% of the boat is glassed all the way across
> and only the middle 25% has the join, so the section is a V between
> two semi circles, which is.  It was also not very shallow.
>
> > What was the ambient temperature during this run compared to the
> > previous? A blow heater through the guts may help. Possibly some thin
> > cheap ply on the outside and inside to keep the bending more even
>
> 20C.  Some heat may help, I will try it tomorrow when I bend this one.
>  I am also using 4mm Polycore for the 3m hull instead of 6mm.
> >
> > To avoid stretch when squashing, a long as possible heat conductive
> > piece of stiff flat metal-possibly box section insulated on three
> > sides, so that you can blow heat down the middle. It then gets pressed
> > all at once rather than squashing it little by little- the process
> > used in spinning and beating metals.
>
> Needs to be seriously hot.  I had the wife's clothes iron on full heat
> and even then it was not a quick operation.  Bog on the edges works
> (but not if it is vacuumed) or it would not be too difficult to make a
> bog bevel.   On the bigger boats, could put a roll of uni or tow along
> the edge to make the step.
>
> > No need to make any comments about slopping resin where it is not
> > needed;>(
>
> Bloody stupid sums it up pretty well.
>
> > Thanks for making the mistakes so we don't have to make as many
>
> My pleasure.
>
> regards,
>
> Rob
> > Robert
> >
> > -- In harryproa@..., "Rob Denney" <harryproa@> wrote:
> > >
> > > G'day,
> > >
> > > Folded up the ww harriette hull today. Did not go well. Mostly
> > because I
> > > rushed it. The centre piece folded beautifully, although it took a
> > bit more
> > > effort than I thought it would. I was concentrating on the
middle and
> > > thought the ends would be following suit. They weren't. The
> > Polycore did
> > > not bend evenly on either side iof the centreline, resulting in a
> > mess. At
> > > one end this was caused by some spilt resin stiffening one side more
> > than
> > > the other, but at the other it just bent crooked, which is a worry.
> > >
> > > The centre section had a fore and aft join along the middle
(trying to
> > > minimise material use) which bent as a V instead of a semicircle
> > like the
> > > rest of it. I also tried ironing the Polycore to taper the edges,
> > as per
> > > the NidaPlast site. It worked, but stretched the material on the
> > underside
> > > so it ended up as a wavy edge which needed to be filled. This had
> > not shown
> > > up on the short pieces I had experimented on.
> > >
> > > Bit disappointing, but the lessons learnt are:
> > > 1) Keep resin off unglassed areas
> > > 2) No fore and aft joins in areas to be bent
> > > 3) Lock the centreline to the table before bending. I used a long
> > straight
> > > edge clamoped to the table for the experiments, completely forgot
> > this time.
> > > 4) Slow bending is even bending. I suspect foam would bend more
> > uniformly,
> > > but would have to be even slower to stop it breaking.
> > >
> > > So, some serious abuse of me by me, some stroppy responses to
> > various forums
> > > (better pressure relief valve than kicking the cat or shouting at
> > the wife
> > > and kid) and I am trying again today.
> > >
> > > regards,
> > >
> > > Rob
> > >
> >
> >
>

G'day,

There are a few variables to sort out but the basics are as follows:

ww hull and decks and bulkheads  area 6 sq m/65 sq'
lw hull and decks and bulkheads 14 sq m/150 sq'
Beams 5 sq m/54 sq'
Booms 2 sq m/12 sq'
Rudders 4 sq m/24 sq'
Total 31 sq m/335 sq' all of which are 5mm/0.2" core (timber or foam)
with 300 gsm/9 ounce glass each side of the foam, 200 gsm/6 ounce uni
glass each side of the timber
The beams also have 3 kgs/6.6 lbs of carbon tow, or 5 kgs/11 pounds of
uni glass, the booms 1kg/2.2 lbs of tow or 2kgs/4.4 lbs of uni glass
and the rudders 3 kgs/6.6 lbs of carbon tow.
The masts are 2 kgs/4.4 lbs of 300 gsm/9 ounce glass and 4 kgs.8.8 lbs
of carbon tow.

Depending on where you are, carbon tow is $45/kg or $21/lb.  I can get
the other prices if you are in Australia, or contact your local
supplier.

The above does not include wastage, filling and gluing powders, paint,
tramp, tent, sails, sheets or deck gear.  I can give you specifics on
these once I know exactly what you want to build.

Any questions, please let me know.

Regards,

Rob





On Thu, Jul 3, 2008 at 4:47 PM, chesterdave <chesterdave@...> wrote:
> Hi everyone, Ive been interested in the camping version of the
> elementarry for quite some time and Im wondering if anyone has a basic
> knowledge of how much materials would be needed to build one. Any help
> would be greatly appreciated,
> DAVE
>
>

Hi everyone, Ive been interested in the camping version of the
elementarry for quite some time and Im wondering if anyone has a basic
knowledge of how much materials would be needed to build one.  Any help
would be greatly appreciated,
DAVE

I'd like to add some small points. The Harry ww hulls are not really
that heavy. Traditional canoes hulls would be a fair bit heavier, so
it would be difficult with traditional materials. By the time some of
the Pacific Proas add their ballast, they are getting up to a
significant proportion of the Harry ww Hull. For a cruising Harry a
Ballestrom makes more sense than a una as the proportion of the weight
of the ww hull can be greater. Windage is a big factor when the winds
are strong enough to need to reduce sail, as the relative windage of
the ww hull increases, though this is somewhat balanced by the windage
of the lw hull

If you are a bit wary of loading up a rudder that can reverse, you
could always have a dagger board set up towards the ends to take some
of the LWR and have a smaller rudder
-- In harryproa@..., "k_s_oneill" <K_S_ONeill@...> wrote:
>
> --- In harryproa@..., "gardnerpomper" <gardner@> wrote:
> >
> > Hi,
> >
> > I was searching for info on proas, other than the harryproa website
> and this forum, and I
> > came across an old message (from 2003) that mentioned that the
> weight to windward proa
> > design was new and had traditionally been ignored because it was
> believed that it would be
> > unable to shunt properly.
> >
> > Does anyone know if this really was the assumption and why? The
> harry's obviously shunt.
> > Did Rob do something special to make that work, or was this just
> another case of "everyone
> > knows that a heavier object will fall faster" ?
>
> I can't find the message you're referring to.  Can you copy the
> message number to your reply?
>
> Without seeing the specific statement, I can say that I was dubious
> they would shunt quickly or reliably when I first saw one.  Rob can
> explain better than I how his boats work, but perhaps I can explain
> why I thought what I thought.
>
> In general, the CLR of a symmetric hull is at about 25% of the way
> back (from the bow).  So a proa often has the CE of the sail moved way
> forward to match that, more or less.  If the CE is way back, as it is
> on a ballestron rig, or worse on an una rig, the boat will often 'not
> shunt', which is to say when you try to shunt it will spin up to
> windward very hard, and often tack and go aback.  That can happen even
> if you have a rudder, the sail's aft CE can just overpower the rudder
> and around you go.  That's bad.  I'm not saying that's what Harrys do,
> mind, I'm just saying that's the sort of general thing that people
> who've had frustrating days on lakes with amateur-designed proas tend
> to think about.
>
> Weight in the ama makes this worse.  The ama is shorter than the main
> hull, so it doesn't want to go as fast anyway, and it's often made too
> small on the first iteration of a boat's design.  So if you put weight
> on the ama you sink it, and if you do that during a shunt there's no
> way the boat will shunt, if you're lucky you just sit there, if not
> you tack.  Again, some of us have done this, so some of us thought
> about weight in the ama during a shunt as an inherently bad idea.
>
> So that's what people were thinking about when they looked at Harrys
> at first, perhaps.  I think it's more or less what I was thinking.
> The CE is well back, compared to a Gibbons rig or a crab claw.  The
> ama is loaded up.  One would tend to wonder if it's going to shunt,
> wouldn't one?
>
> As I said, Rob can no doubt explain his boats better than I can, but
> having said what I was worried about with respect to Harrys, here's
> what I've come to think, and he can correct me where he thinks I'm
> mistaken;  the CLR is still at about 25% of the way back from the bow.
>  Harrys aren't magic, nor is a lack of rocker in the lee hull really
> an answer to where the CLR ends up.  The CLR of the lee hull is where
> it is, it's way forward.  But Harrys have rounded hulls rather than
> traditional sharp proa hulls of whatever cross section, which makes
> the magnitude of the hull's lift fairly small when compared to the
> lift of the rudder, much smaller than you would get with a
> sharp-keeled hull and smaller rudders, for example.  So the shape of
> the hull and the size of the rudders lets Rob dominate the CLR of the
> whole system with the rudders.  That's the key, to me.  It's also nice
> that he can keep the front rudder down during the shunt and have it
> push to lee for a second as the boat gets going, I think that could
> save the day every once in a while.
>
> In a secondary sense, the weight in the windward hull of a Harry isn't
> the problem it would be if you loaded up a traditional proa ama;
> you're not going to sink a Harry 'ama'.  The windward hull's drag may
> be more than the lee hull, but again it's small enough to be dominated
> by the rudder.
>
> This also explains, to me at least, why people haven't copied Harrys
> much.  I actually thought about what Rob had done and built a set of
> big-assed 5 ft long rudders to put on my boat, but I'm scared to try
> them, I really think they might tear the boat in half or something.  I
> went back to a big long leeboard on a hefty mount in the middle of the
> boat and beachcat sized rudders.  Engineering steering foils that size
> that have to steer, kick up, spin 180 degrees to shunt, and not break,
> it's not an easy thing, and once you draw them you have to have the
> materials expertise to make them strong enough.
>
> Kevin
>

--- In harryproa@..., "Rob Denney" <harryproa@...> wrote:
>
> G'day,
To make a hot press, get some steel box section insulated on three
sides-rockwool or glass wool  batts semi permanently and one the other
side with a removable skin. Lean it at an angle between 30 and 60
degrees against a wall removable skin side upper side upper and stick
  a propane torch in the bottom end. Channel on its side may work
better as you could poke the propane torch along the length to give it
better control of temperature.

G'day,

Gardner, it was pretty much a case of everyone knowing, no one trying
it.  As kevin says, harrys are not magic.  Also, 10 years of playing
with them has thrown up a whole heap of things that were not obvious
to me at the beginning.  Kevin's analysis is pretty much correct, I
have added comments to his text.


> I can't find the message you're referring to. Can you copy the
> message number to your reply?

It is almost certainly the John Dalziel article, The Case for the
Pacific Proa, which can be seen on Joe Oster's web page
http://www.wingo.com/proa/links.html along with some other anti
harry/Denney stuff, some interesting traditional and historical stuff
and some videos showing why  V hulls and sloop rigs are not ideal for
proas .  John's article has been modified since it was first written
(and I critiqued it) to remove some of the over the top  claims, but
is still mostly wishful thinking.
>
> Without seeing the specific statement, I can say that I was dubious
> they would shunt quickly or reliably when I first saw one. Rob can
> explain better than I how his boats work, but perhaps I can explain
> why I thought what I thought.
>
> In general, the CLR of a symmetric hull is at about 25% of the way
> back (from the bow). So a proa often has the CE of the sail moved way
> forward to match that, more or less. If the CE is way back, as it is
> on a ballestron rig, or worse on an una rig, the boat will often 'not
> shunt', which is to say when you try to shunt it will spin up to
> windward very hard, and often tack and go aback. That can happen even
> if you have a rudder, the sail's aft CE can just overpower the rudder
> and around you go. That's bad. I'm not saying that's what Harrys do,
> mind, I'm just saying that's the sort of general thing that people
> who've had frustrating days on lakes with amateur-designed proas tend
> to think about.

You are correct about the coe when the boat is moving and near enough
hard on the wind, but not when it is stationary, which is the case
when shunting.    Harry's can be made to luff into irons after a
shunt, the same way a bad tack will put a conventional boat into
irons.  But it is much easier to get shunting right than tacking.  The
2 tricks are:
Do NOT sail onto a reach to shunt.  If anything luff almost head to
wind, dump the sheet, rotate the rudders and sheet on.  This gets the
boat moving on a very broad reach and allows it to get some speed so
the rudders can do their job.  It also gets you some free distance to
windward.
If the boat is still  luffing faster than you want it to, dump the
sheet, which removes the luffing force and makes it much easier to get
back on track.
>
> Weight in the ama makes this worse. The ama is shorter than the main
> hull, so it doesn't want to go as fast anyway, and it's often made too
> small on the first iteration of a boat's design. So if you put weight
> on the ama you sink it, and if you do that during a shunt there's no
> way the boat will shunt, if you're lucky you just sit there, if not
> you tack. Again, some of us have done this, so some of us thought
> about weight in the ama during a shunt as an inherently bad idea.

Again it is a low or no speed thing.  Harry windward hulls are short
and (relatively) fat so they are actually pretty easy to move at low
speeds.  The theory of the boat luffing around the windward hull is
pretty hard to dispute, but in practise, there is almost no difference
to the steering when the hull is flying or not.  Same applies to
catamarans.
>
> So that's what people were thinking about when they looked at Harrys
> at first, perhaps. I think it's more or less what I was thinking.
> The CE is well back, compared to a Gibbons rig or a crab claw. The
> ama is loaded up. One would tend to wonder if it's going to shunt,
> wouldn't one?
>
> As I said, Rob can no doubt explain his boats better than I can, but
> having said what I was worried about with respect to Harrys, here's
> what I've come to think, and he can correct me where he thinks I'm
> mistaken; the CLR is still at about 25% of the way back from the bow.
> Harrys aren't magic, nor is a lack of rocker in the lee hull really
> an answer to where the CLR ends up.

True, but it does help a lot with directional stability.  Turning even
a lightly loaded harry is hard work.  The rocker also serves to keep
the bow up, which stops the clr moving as far forward as a rockered
hull which tends to pitch forward when the rig loads up.

The CLR of the lee hull is where
> it is, it's way forward. But Harrys have rounded hulls rather than
> traditional sharp proa hulls of whatever cross section, which makes
> the magnitude of the hull's lift fairly small when compared to the
> lift of the rudder, much smaller than you would get with a
> sharp-keeled hull and smaller rudders, for example. So the shape of
> the hull and the size of the rudders lets Rob dominate the CLR of the
> whole system with the rudders. That's the key, to me. It's also nice
> that he can keep the front rudder down during the shunt and have it
> push to lee for a second as the boat gets going, I think that could
> save the day every once in a while.

The big rudders, no fixed foils definitely helps, although U
(7.5m/25')  had extreme beam, big fat windward hull, a leeboard (then
a weatherboard) and small rudders on the ends, yet still shunted well
with flat bottom hulls and rocker.   There are still a heap of things
to try, just not enough time.
>
> In a secondary sense, the weight in the windward hull of a Harry isn't
> the problem it would be if you loaded up a traditional proa ama;
> you're not going to sink a Harry 'ama'. The windward hull's drag may
> be more than the lee hull, but again it's small enough to be dominated
> by the rudder.
>
> This also explains, to me at least, why people haven't copied Harrys
> much. I actually thought about what Rob had done and built a set of
> big-assed 5 ft long rudders to put on my boat, but I'm scared to try
> them, I really think they might tear the boat in half or something. I
> went back to a big long leeboard on a hefty mount in the middle of the
> boat and beachcat sized rudders. Engineering steering foils that size
> that have to steer, kick up, spin 180 degrees to shunt, and not break,
> it's not an easy thing, and once you draw them you have to have the
> materials expertise to make them strong enough.

The trick for testing rudder systems is to make them as exposed as
possible, with scope to beef them up as required.  Don't sail them
until they break, sail them until they bend or crack and add material.
  Means much shorter sailing days (sometimes not much more than out to
to rudder depth and back home), but less time in the shop.  Put your
5'ters in (sounds too big to me), you will not regret it. Let me know
if you want any help with the layout, engineering or materials
expertise, the difference between a carbon laminate at Boeing and one
in your shed is not as big as you think.

It is a long while since I have broken a rudder, and a fair while
since I have broken the support.  Once you have a feel for the loads,
it is pretty easy to build things strong enough, particularly if you
can arrange the support to be in tension, or short compression
members, rather than bending, torsion or sheer. Rudders on the beams
makes it much easier than rudders  in or attached to the hulls.

Another thing about beam mounted rudders/no daggerboard is that if
only one rudder  is used, the clr moves way aft, which has some
balancing effect just after the shunt.  These days, I tend to shunt by
dumping the sheet, lifting the old rudder, lowering the new one,
sheeting on and sailing away.  It is very rare that I stuff up a
shunt.    My standard teaching tactic is to take the newbie for a
sail, shunt twice, and get off and leave him/her to it.  Very few
stuff it up and if they do (usually because of the inadequate rudder
lifting/lowering system), they just reverse the rudder and sail out of
it.  Rudders and rigs that can freely rotate through 360 degrees make
this a lot easier.

Off to lay up harriette windward hull number 2.  Any of the above that
is unclear, please let me know and i will add some detail.

regards,

Rob
>
> Kevin
>
>

G'day,

On Wed, Jul 2, 2008 at 2:03 PM, Robert <cateran1949@...> wrote:
>
> G'day Rob,
> -To give you someone else to swear at for stating the obvious with
> 20/20 hindsight from my armchair.
> Extra bog or extra glass to avoid the centre V.

Would need to be quite a bit of extra glass (basalt, actually) as it
is only 200 gsm.  Bog may have done it, but it introduces another
variable.

>
> Can't see that a
> shallow V is a problem

It's not, but the middle 50% of the boat is glassed all the way across
and only the middle 25% has the join, so the section is a V between
two semi circles, which is.  It was also not very shallow.

> What was the ambient temperature during this run compared to the
> previous? A blow heater through the guts may help. Possibly some thin
> cheap ply on the outside and inside to keep the bending more even

20C.  Some heat may help, I will try it tomorrow when I bend this one.
  I am also using 4mm Polycore for the 3m hull instead of 6mm.
>
> To avoid stretch when squashing, a long as possible heat conductive
> piece of stiff flat metal-possibly box section insulated on three
> sides, so that you can blow heat down the middle. It then gets pressed
> all at once rather than squashing it little by little- the process
> used in spinning and beating metals.

Needs to be seriously hot.  I had the wife's clothes iron on full heat
and even then it was not a quick operation.  Bog on the edges works
(but not if it is vacuumed) or it would not be too difficult to make a
bog bevel.   On the bigger boats, could put a roll of uni or tow along
the edge to make the step.

> No need to make any comments about slopping resin where it is not
> needed;>(

Bloody stupid sums it up pretty well.

> Thanks for making the mistakes so we don't have to make as many

My pleasure.

regards,

Rob
> Robert
>
> -- In harryproa@..., "Rob Denney" <harryproa@...> wrote:
> >
> > G'day,
> >
> > Folded up the ww harriette hull today. Did not go well. Mostly
> because I
> > rushed it. The centre piece folded beautifully, although it took a
> bit more
> > effort than I thought it would. I was concentrating on the middle and
> > thought the ends would be following suit. They weren't. The
> Polycore did
> > not bend evenly on either side iof the centreline, resulting in a
> mess. At
> > one end this was caused by some spilt resin stiffening one side more
> than
> > the other, but at the other it just bent crooked, which is a worry.
> >
> > The centre section had a fore and aft join along the middle (trying to
> > minimise material use) which bent as a V instead of a semicircle
> like the
> > rest of it. I also tried ironing the Polycore to taper the edges,
> as per
> > the NidaPlast site. It worked, but stretched the material on the
> underside
> > so it ended up as a wavy edge which needed to be filled. This had
> not shown
> > up on the short pieces I had experimented on.
> >
> > Bit disappointing, but the lessons learnt are:
> > 1) Keep resin off unglassed areas
> > 2) No fore and aft joins in areas to be bent
> > 3) Lock the centreline to the table before bending. I used a long
> straight
> > edge clamoped to the table for the experiments, completely forgot
> this time.
> > 4) Slow bending is even bending. I suspect foam would bend more
> uniformly,
> > but would have to be even slower to stop it breaking.
> >
> > So, some serious abuse of me by me, some stroppy responses to
> various forums
> > (better pressure relief valve than kicking the cat or shouting at
> the wife
> > and kid) and I am trying again today.
> >
> > regards,
> >
> > Rob
> >
>
>

--- In harryproa@..., "gardnerpomper" <gardner@...> wrote:
>
> Hi,
>
> I was searching for info on proas, other than the harryproa website
and this forum, and I
> came across an old message (from 2003) that mentioned that the
weight to windward proa
> design was new and had traditionally been ignored because it was
believed that it would be
> unable to shunt properly.
>
> Does anyone know if this really was the assumption and why? The
harry's obviously shunt.
> Did Rob do something special to make that work, or was this just
another case of "everyone
> knows that a heavier object will fall faster" ?

I can't find the message you're referring to.  Can you copy the
message number to your reply?

Without seeing the specific statement, I can say that I was dubious
they would shunt quickly or reliably when I first saw one.  Rob can
explain better than I how his boats work, but perhaps I can explain
why I thought what I thought.

In general, the CLR of a symmetric hull is at about 25% of the way
back (from the bow).  So a proa often has the CE of the sail moved way
forward to match that, more or less.  If the CE is way back, as it is
on a ballestron rig, or worse on an una rig, the boat will often 'not
shunt', which is to say when you try to shunt it will spin up to
windward very hard, and often tack and go aback.  That can happen even
if you have a rudder, the sail's aft CE can just overpower the rudder
and around you go.  That's bad.  I'm not saying that's what Harrys do,
mind, I'm just saying that's the sort of general thing that people
who've had frustrating days on lakes with amateur-designed proas tend
to think about.

Weight in the ama makes this worse.  The ama is shorter than the main
hull, so it doesn't want to go as fast anyway, and it's often made too
small on the first iteration of a boat's design.  So if you put weight
on the ama you sink it, and if you do that during a shunt there's no
way the boat will shunt, if you're lucky you just sit there, if not
you tack.  Again, some of us have done this, so some of us thought
about weight in the ama during a shunt as an inherently bad idea.

So that's what people were thinking about when they looked at Harrys
at first, perhaps.  I think it's more or less what I was thinking.
The CE is well back, compared to a Gibbons rig or a crab claw.  The
ama is loaded up.  One would tend to wonder if it's going to shunt,
wouldn't one?

As I said, Rob can no doubt explain his boats better than I can, but
having said what I was worried about with respect to Harrys, here's
what I've come to think, and he can correct me where he thinks I'm
mistaken;  the CLR is still at about 25% of the way back from the bow.
  Harrys aren't magic, nor is a lack of rocker in the lee hull really
an answer to where the CLR ends up.  The CLR of the lee hull is where
it is, it's way forward.  But Harrys have rounded hulls rather than
traditional sharp proa hulls of whatever cross section, which makes
the magnitude of the hull's lift fairly small when compared to the
lift of the rudder, much smaller than you would get with a
sharp-keeled hull and smaller rudders, for example.  So the shape of
the hull and the size of the rudders lets Rob dominate the CLR of the
whole system with the rudders.  That's the key, to me.  It's also nice
that he can keep the front rudder down during the shunt and have it
push to lee for a second as the boat gets going, I think that could
save the day every once in a while.

In a secondary sense, the weight in the windward hull of a Harry isn't
the problem it would be if you loaded up a traditional proa ama;
you're not going to sink a Harry 'ama'.  The windward hull's drag may
be more than the lee hull, but again it's small enough to be dominated
by the rudder.

This also explains, to me at least, why people haven't copied Harrys
much.  I actually thought about what Rob had done and built a set of
big-assed 5 ft long rudders to put on my boat, but I'm scared to try
them, I really think they might tear the boat in half or something.  I
went back to a big long leeboard on a hefty mount in the middle of the
boat and beachcat sized rudders.  Engineering steering foils that size
that have to steer, kick up, spin 180 degrees to shunt, and not break,
it's not an easy thing, and once you draw them you have to have the
materials expertise to make them strong enough.

Kevin

Hi,

I was searching for info on proas, other than the harryproa website and this
forum, and I
came across an old message (from 2003) that mentioned that the weight to
windward proa
design was new and had traditionally been ignored because it was believed that
it would be
unable to shunt properly.

Does anyone know if this really was the assumption and why? The harry's
obviously shunt.
Did Rob do something special to make that work, or was this just another case of
"everyone
knows that a heavier object will fall faster" ?

- Gardner

G'day Rob,
-To give you someone else to swear at for stating the obvious with
20/20 hindsight from my armchair.
Extra bog or extra glass to avoid the centre V. Can't see that a
shallow V is a problem
What was the ambient temperature during this run compared to the
previous? A blow heater through the guts may help. Possibly some thin
cheap ply on the outside and inside to keep the bending more even

To avoid stretch when squashing, a long as possible heat conductive
piece of stiff flat metal-possibly box section insulated on three
sides, so that you can blow heat down the middle. It then gets pressed
all at once rather than squashing it little by little- the process
used in spinning and beating metals.
No need to make any comments about slopping resin where it is not
needed;>(
Thanks for making the mistakes so we don't have to make as many
  Robert

-- In harryproa@..., "Rob Denney" <harryproa@...> wrote:
>
> G'day,
>
> Folded up the ww harriette hull today.  Did not go well.  Mostly
because I
> rushed it.  The centre piece folded beautifully, although it took a
bit more
> effort than I thought it would.    I was concentrating on the middle and
> thought the ends would be following suit.  They weren't.  The
Polycore did
> not bend evenly on either side iof the centreline, resulting in a
mess.  At
> one end this was caused by some spilt resin stiffening one side more
than
> the other, but at the other it just bent crooked, which is a worry.
>
> The centre section had a fore and aft join along the middle (trying to
> minimise material use) which bent as a V instead of a semicircle
like the
> rest of it.   I also tried ironing the Polycore to taper the edges,
as per
> the NidaPlast site.  It worked, but stretched the material on the
underside
> so it ended up as a wavy edge which needed to be filled.  This had
not shown
> up on the short pieces I had experimented on.
>
> Bit disappointing, but the lessons learnt are:
> 1) Keep resin off unglassed areas
> 2) No fore and aft joins in areas to be bent
> 3) Lock the centreline to the table before bending.  I used a long
straight
> edge clamoped to the table for the experiments, completely forgot
this time.
> 4) Slow bending is even bending.  I suspect foam would bend more
uniformly,
> but would have to be even slower to stop it breaking.
>
> So, some serious abuse of me by me, some stroppy responses to
various forums
> (better pressure relief valve than kicking the cat or shouting at
the wife
> and kid) and I am trying again today.
>
> regards,
>
> Rob
>

--- In harryproa@..., "chris483035" <joooody2@...> wrote:
>
> Hi Kevin,
>
> That is a great solution and as you say removes the compression load
on the mast.  Those
> Spinlock cleats are really good and lend themselves to unusual jobs.
  I am sure they have
> many other applications as yet unthought of.

I hope it's useful.  I'd encourage anyone thinking of using them for
masttop applications like this to make a mockup first, though, and
make sure it works on your mast and with your halyard and track and so on.

>
> I'll second the vote of thanks for the Texas 200 coverage.  It
sounds like you have put
> together a really capable boat that doesn't need to make any excuses
for being a proa.

Thanks, to both of you.  Glad you enjoyed it.

Kevin