Re: Cold Molded Construction

Nels, I confess I am having difficulty understanding your point.
The original poster is interested in building a cold moulded trailer
boat. I have built 3 hulls, and gave him some opinions. I enjoyed
building moulded boats, and have built several ply boats. Moulded
round bilge boats would be my choice for the next one I build.
Why are you trying to convince me otherwise? I am sure you have the
best of intentions though. :)
Cheers,
DonB

> Hi Don,
>
> Depending on the size of a trailerable boat, you might look at the
> Chebacco website. Chebacco plans are available in several
> configurations including a motorsailer version.
>
> There was a comparison done in SBJ a long time ago with three
> versions compared, the plywood, lapstrake plywood and either cold
> molded or stripper planked.
>
> From a visual standpoint I admired the plywood boat and it was
judged
> to be the fastest I believe.
>
> Cerainly the quickest to build. Therefore the majority of builders
> use this method.
>
> But there are more details at the Chebacco site.
>
> In the small homebuilt plane market, aerolite was the glue of
choice
> at one time, particularly when covering with fabric. But I believe
> that expoxy is almost used exclusively now.
>
> Guess there ar many other glues as well. But whether you have to
> slather glue on wood or foam or any other material, it would not
be
> my first choice when there is wood available that has already be
pre-
> manufactured using pressure glued laminations and no clamping is
> needed.
>
> Nels
>
> --- In bolger@y..., "dbaldnz" <oink@p...> wrote:
> > Hi Nels, maybe you did not see my earlier podt. The boat we are
> > discussing is a trailer craft, and you don't need to use
expensive
> > epoxy. Aerolite 300 is more than adequate, with lots of other
> > advantages as well.
> > The only extra tool you need is a spring powered stapler.
> > As for comparing with flat boats...there is no comparison. You
> > either want to create a beautiful boat, or you want an easy to
> build
> > simple but not neccessarily cheaper if you build it) craft.
> > Labour is perhaps free if producing a lovely hull is a joy.
> > I like to touch wood. I would rather touch a dead fish than
glass
> > and foam!
> > DonB
> >
Size does matter if you plan on trailering your boat any distance.
Where I live most boats spend their time on a trailer or a roof rack
and never get left at a marina.

The smaller and lighter a boat is the more it seems to get used and
that is whole point for me.

So it is of prime importance to get the most interior room from the
smallest and lightest hull form.

I don't quite understand the idea of taking something simple and
making it more complicated. I do see the genius in accomplishing the
opposite.

Nels

--- In bolger@y..., "proaconstrictor" <proaconstrictor@y...> wrote:
>
I just don't believe in the argument
that goes "most boat in a a 16' space" as though we were taking
delivery in some small container. Sure cost may vary, but it isn't
an open minded analysis saying "what is the biggest boat I can get in
16'", if a twenty foot boat would work better. It is just rigidity
of thinking.
Hi Don,

Depending on the size of a trailerable boat, you might look at the
Chebacco website. Chebacco plans are available in several
configurations including a motorsailer version.

There was a comparison done in SBJ a long time ago with three
versions compared, the plywood, lapstrake plywood and either cold
molded or stripper planked.

From a visual standpoint I admired the plywood boat and it was judged
to be the fastest I believe.

Cerainly the quickest to build. Therefore the majority of builders
use this method.

But there are more details at the Chebacco site.

In the small homebuilt plane market, aerolite was the glue of choice
at one time, particularly when covering with fabric. But I believe
that expoxy is almost used exclusively now.

Guess there ar many other glues as well. But whether you have to
slather glue on wood or foam or any other material, it would not be
my first choice when there is wood available that has already be pre-
manufactured using pressure glued laminations and no clamping is
needed.

Nels

--- In bolger@y..., "dbaldnz" <oink@p...> wrote:
> Hi Nels, maybe you did not see my earlier podt. The boat we are
> discussing is a trailer craft, and you don't need to use expensive
> epoxy. Aerolite 300 is more than adequate, with lots of other
> advantages as well.
> The only extra tool you need is a spring powered stapler.
> As for comparing with flat boats...there is no comparison. You
> either want to create a beautiful boat, or you want an easy to
build
> simple but not neccessarily cheaper if you build it) craft.
> Labour is perhaps free if producing a lovely hull is a joy.
> I like to touch wood. I would rather touch a dead fish than glass
> and foam!
> DonB
>
Hi Nels, maybe you did not see my earlier podt. The boat we are
discussing is a trailer craft, and you don't need to use expensive
epoxy. Aerolite 300 is more than adequate, with lots of other
advantages as well.
The only extra tool you need is a spring powered stapler.
As for comparing with flat boats...there is no comparison. You
either want to create a beautiful boat, or you want an easy to build
simple but not neccessarily cheaper if you build it) craft.
Labour is perhaps free if producing a lovely hull is a joy.
I like to touch wood. I would rather touch a dead fish than glass
and foam!
DonB

> Dear Don,
>
> No Labor is "free" if your first love is to get out on the water.
>
> Although the wood may be cheaper, the cost of the epoxy would
likely
> make the boat more expensive. Then there is the expense of the
extra
> tools you may need to prepare the veneer and hold it in place
while
> the glue dries.
>
> My guess is that when Bolger and Payson developed the designs for
> quick homebuilding they pretty much discounted these alternatives.
A
> big factor turned out to be that with all the beautiful curves you
> can form with cold moulding, the end performance was not really
> improved all that much. A huge advantage of straight and flat
> surfaces is the ease as to how the interior can be finished and
that
> you get the maximum amount of interior room given the outer
> dimensions.
>
> Of course it is still an interesting concept. But I wonder why use
> wood at all? Just use foam and cloth. Or do like canoeists, and
build
> a cedar stripper?
>
> Nels
--- In bolger@y..., "Nels" <arvent@h...> wrote:
> --- In bolger@y..., "proaconstrictor" <proaconstrictor@y...> wrote:
> >
> > >
> > > Although the wood may be cheaper, the cost of the epoxy would
> > likely
> > > make the boat more expensive. Then there is the expense of the
> > extra
> > > tools you may need to prepare the veneer and hold it in place
> while
> > > the glue dries.
> >
> > Circular saw and stapple gun?
> > >
> Ok - So cold molding only takes one more tool:-)
>
> I believe orignally, builders used to re-saw their own veneers and
> this required a big old bandsaw. I would want an air compressor to
> evenly drive all those staples too.

Could be. Up until the spotted own shut down the west coats or
whatever, we had the dean company providing beautiful veneer at ver
reasonable cost. It was sliced, which is zero loss compared to
sawing.
>
> We are all probably familiar with Bjorn Harbo's building sequence
for
> his 25 foot schooner. He rough constructed a ladder frame to
support
> the hull bottom and then started erecting bulkheads most which
became
> a permanent part of the interior. Then he attached the topsides and
> decking etc.

Like spilled and steamed planks, or nailled on plywood

>
> If we wanted to construct a cold-molded version based on a
> conventional schooner design what would be our building sequence?
>
> First construct a mold which would have to be a very accurate
> representation of the boats hull?

Are you saying accuracy is slow, or just good workmanship

>
> Then we would have to install some sort of release material on it.

You can build over permanent bulkheads also, but you don't need many
frames, so is that faster or slower?

> Then begin the veneering process. How many layers of 1/8 inch
veneer
> I wonder? Then fair it and glass it etc.

So we aren't fairing Bjorns boat. Must be plywood? So the point is
that the whole surface of a plywood boat is unfair (below highest
point at seams). I would also recomend not trying to make it fair.
Sad really.
>

You aren't restricted to double d veneer, and you can use any
thinkness comensurate with the design in question


> Now we have to pull and lift the hull off the form and turn it over
> without damaging it right?

Tip: Serve beer afterwards. Not before.

>
> Now we would have to build a support frame for it - sorta like
Bjorn
> did in step one right?

More 400 dollar hammers apparently

>
> Now I begin to wonder what we do next? We have this smooth interior
> shell which is probably pretty slippery and we have to install all
> the interior joinery, with no frames or excresences (PCB word;-))
to
> attach anything to.

It's wood. They have this stuff called glue...

We also have to deck it over and attach some sort
> of keel and floors and rudder support system.

It may well be necesary to make a boat before we are done...

>
> Then after that is all done, I have a tradional style schooner that
> is beautiful to behold, yet pretty much maintenance free.

Eureka! And better ballast ratio and so forth.

>
> I actually sailed on a traditional 25 foot schooner once and was
> thrilled. However I was surprised how small the cockpit and cabin
was
> and how dark it was below. And I would not want to have to try to
> trailer it anywhere.
>
> Somehow to my mind the Bolger designs and building methods don't
seem
> so shabby and outmoded to me!
>
> What am I missing here?

Well the only "shabby" comment I made was relative to the USeof Home
Depot materials without any epoxy. So you have non-marine grade
materials getting a workout. They may last forever, or just a year,
but the end of the quality spectrum I put that at is the opposite of
the gold platter. The coment tried to position a vast range of
posibl alternative to the unspeakable as way to expensive for
consideration, which is ridiculous.

Also you might be missing out on Constant Camber, where the whole
half hull could be layed up in three hours and cured in bag.

>
> Nels
> I suppose there comes a point in size where it hardly matters what
> the hull shape is like,there is room to swing a herd of buffalo
never
> mind the proverbial cat.However,in the smaller sizes like a
weekender
> or overnighter type(lets say 20' or less) the box shape has it all
> over the more conventional"boat" shape.A quick example of this may
be
> readily observed if we were to compare the Bolger MICRO and the
> NORDICA 16.The Nordica will sleep two as long as you do not need to
> sit upright in the cabin.The Micro will also sleep two but can sit
4
> people,upright,in comfort.I've sailed both and know the volumes
just
> do not compare.
> Who cares? Anyone looking to get the most boat for size and
> money,most likely on a restricted time/money budget,and few pre-
> concieved notions of what is"right".

It isn't the preconceived notions, it is just taking different trade-
offs. Like wave slap. I didn't argue (I hope) that you can't make a
cheapper boat in a box shape, I just don't believe in the argument
that goes "most boat in a a 16' space" as though we were taking
delivery in some small container. Sure cost may vary, but it isn't
an open minded analysis saying "what is the biggest boat I can get in
16'", if a twenty foot boat would work better. It is just rigidity
of thinking. And as good as these boats are, it isn't a foregone
conclusion square is better, or I am pretty confused about all those
other boats bolger designs.


> In the end,we all have our perfect ship just waiting to be built
the
> day the numbers come through for us in our local lottery racket.Our
> ideas will be regurgitated from stuff spotted in a beautiful
picture
> somewhere. None of it will really matter all that much since it
will
> be the myth we chased and not the truth we needed.
> Sincerely,
> Peter Lenihan

Nicely put. Beauty has truth of its own.
--- In bolger@y..., "proaconstrictor" <proaconstrictor@y...> wrote:
>
> >
> > Although the wood may be cheaper, the cost of the epoxy would
> likely
> > make the boat more expensive. Then there is the expense of the
> extra
> > tools you may need to prepare the veneer and hold it in place
while
> > the glue dries.
>
> Circular saw and stapple gun?
> >
Ok - So cold molding only takes one more tool:-)

I believe orignally, builders used to re-saw their own veneers and
this required a big old bandsaw. I would want an air compressor to
evenly drive all those staples too.

We are all probably familiar with Bjorn Harbo's building sequence for
his 25 foot schooner. He rough constructed a ladder frame to support
the hull bottom and then started erecting bulkheads most which became
a permanent part of the interior. Then he attached the topsides and
decking etc.

If we wanted to construct a cold-molded version based on a
conventional schooner design what would be our building sequence?

First construct a mold which would have to be a very accurate
representation of the boats hull?

Then we would have to install some sort of release material on it.
Then begin the veneering process. How many layers of 1/8 inch veneer
I wonder? Then fair it and glass it etc.

Now we have to pull and lift the hull off the form and turn it over
without damaging it right?

Now we would have to build a support frame for it - sorta like Bjorn
did in step one right?

Now I begin to wonder what we do next? We have this smooth interior
shell which is probably pretty slippery and we have to install all
the interior joinery, with no frames or excresences (PCB word;-)) to
attach anything to. We also have to deck it over and attach some sort
of keel and floors and rudder support system.

Then after that is all done, I have a tradional style schooner that
is beautiful to behold, yet pretty much maintenance free.

I actually sailed on a traditional 25 foot schooner once and was
thrilled. However I was surprised how small the cockpit and cabin was
and how dark it was below. And I would not want to have to try to
trailer it anywhere.

Somehow to my mind the Bolger designs and building methods don't seem
so shabby and outmoded to me!

What am I missing here?

Nels
--- In bolger@y..., "proaconstrictor" <proaconstrictor@y...> wrote:

> If the hull is built, give me the curved boat, no stringers, and
> nowadays you could have cad prints for all the hull surfaces.
Anyway
> cutting to fit them is easy. When I build Stressform amas, nasty
> little trenches requiring 10 bulkheads, I figure an hour or two to
> make patterns and cut them all out. At ther end of the day on
bigger
> boats you have a place people actualy want to photograph for a
> magazine, or spend some time in. I have seen quite a few Bolger
> boxes in the pages of WB, for instance, can't remember ever seing a
> picture of the inside, maybe for Jochims?


Perhaps there exists the notion that when fitting interior furniture
it is"easier" and"quicker" to have only to deal with the fore and aft
curve of the hull without figuring the sectional curve as well?
As to interior shots,it all depends on where you saw the pictures in
WB.If in the just launched section,most folks like to show the whole
fruit of their labour as apposed to some crafty bit of joinery
accomplished in the forecastle.Besides,how would we know which boat
exactly that interior shot came from? The articles with the nice
pictures often reflect some extra-ordinary efforts taken by some with
deep pockets.Not exactly your average backyard project.
Sam Devlin has a wonderful web page where one may see some rather
striking interiors from boats with almost straight sides,eg;Czarina
(sp) in plywood.

> and that
> > you get the maximum amount of interior room given the outer
> > dimensions.
>
> This of course would be true for any shape, If you mean for
waterline
> length, or something else like it, it probably isn't true. That's
> just a bunch of nonsense people use to sell designs, you know most
> room for on deck dimension, most room for waterline dimensions.
Who
> cares, except for docking fees in crowded areas with no decent
> cruising to start with.


I suppose there comes a point in size where it hardly matters what
the hull shape is like,there is room to swing a herd of buffalo never
mind the proverbial cat.However,in the smaller sizes like a weekender
or overnighter type(lets say 20' or less) the box shape has it all
over the more conventional"boat" shape.A quick example of this may be
readily observed if we were to compare the Bolger MICRO and the
NORDICA 16.The Nordica will sleep two as long as you do not need to
sit upright in the cabin.The Micro will also sleep two but can sit 4
people,upright,in comfort.I've sailed both and know the volumes just
do not compare.
Who cares? Anyone looking to get the most boat for size and
money,most likely on a restricted time/money budget,and few pre-
concieved notions of what is"right".
In the end,we all have our perfect ship just waiting to be built the
day the numbers come through for us in our local lottery racket.Our
ideas will be regurgitated from stuff spotted in a beautiful picture
somewhere.None of it will really matter all that much since it will
be the myth we chased and not the truth we needed.
Sincerely,
Peter Lenihan
>
> Although the wood may be cheaper, the cost of the epoxy would
likely
> make the boat more expensive. Then there is the expense of the
extra
> tools you may need to prepare the veneer and hold it in place while
> the glue dries.

Circular saw and stapple gun?
>
> My guess is that when Bolger and Payson developed the designs for
> quick homebuilding they pretty much discounted these alternatives.

Good guess.

A
> big factor turned out to be that with all the beautiful curves you
> can form with cold moulding, the end performance was not really
> improved all that much.

There is only so much improvement over swimming also. But your
right, some boats cry out plywood, but bolger makes lots of curvy
ones for other uses, he just hasn't upgraded his construction
techniques to keep pace witht he fact you need your own dealer in
surinam to get the wood to build them. ;0)

A huge advantage of straight and flat
> surfaces is the ease as to how the interior can be finished

If the hull is built, give me the curved boat, no stringers, and
nowadays you could have cad prints for all the hull surfaces. Anyway
cutting to fit them is easy. When I build Stressform amas, nasty
little trenches requiring 10 bulkheads, I figure an hour or two to
make patterns and cut them all out. At ther end of the day on bigger
boats you have a place people actualy want to photograph for a
magazine, or spend some time in. I have seen quite a few Bolger
boxes in the pages of WB, for instance, can't remember ever seing a
picture of the inside, maybe for Jochims?

and that
> you get the maximum amount of interior room given the outer
> dimensions.

This of course would be true for any shape, If you mean for waterline
length, or something else like it, it probably isn't true. That's
just a bunch of nonsense people use to sell designs, you know most
room for on deck dimension, most room for waterline dimensions. Who
cares, except for docking fees in crowded areas with no decent
cruising to start with.

>
> Of course it is still an interesting concept. But I wonder why use
> wood at all? Just use foam and cloth.

That is clearly a big tooling/marketign issue in some cases, though
if core cell, you could be on to something, or KSS.

Or do like canoeists, and build
> a cedar stripper?

Now your talking sense. That's what the pros are using more and
more, the dynamic has changed we have new tools that make this
sensible.
>
> Nels
--- In bolger@y..., "Nels" <arvent@h...> wrote:
> I would guess it is one of the more labour intensive methods as
well
> as being costly in materials. The major benefit is the high
strength
> to weight ratio which is comparable to aircraft requirements. But
how
> many sailboats really need that level of performance?
>
> Perhaps some sailers with deep pockets might think they do... Nels
>
> --- In bolger@y..., "Peter Lenihan" <ellengaest@b...> wrote:
> > > or,perhaps,prefers assembling her boats from material readily
> > (cheaply) available at the nearest lumberyard(mega hardware
store)
> > without the added burden of dealing with alot of epoxy or the
waste
> > from the jig necessary for most well built cold molded boats.On
the.


> > other hand,I ain't Susanne..........
> > Sincerely,
> > Peter Lenihan,amateur boatbuilder and chronic sufferer of the
Peter
> > Pan syndrome,along the banks of the mighty St.Lawrence.......



There is a big gap between gold, and crap.

Making boats out of lumberyard materials without epoxy is certainly a
fine thing, but it is one end of the spectrum, you aren't talking
from the middle of the road. The other end of the Bolger business
includes plank on frame boats that are clearly more expensive to
build and maintain than cold molded boats. I just finished Wooden
Boats the enjoyable story of the Ganon and Benjamin yard, but all
that stuff in there about how P&F boats are easier to maintain...
Well you can't kid a kidder.

It is too bad that we don't have easy sources of venner that are
cheaper (or as cheap) than the finished ply they are destined for.
But that's life, for most of us. Of course the economic status of a
method is totaly based on local pricing, so one shouldn't discount CM
before looking around.

It is reasonably easy to find ply that is good enough for CM. And
anyway, what do you think a double layer of plywood over the bottom
of your Micro, Martha Jane, or Wyo is other than cold molding.

Cost of tooling has to be taken against the outcome, and properly
made it can be faster than hard chine ply, once you have the mold.
--- In bolger@y..., "dbaldnz" <oink@p...> wrote:
> I would bet she means one-off professionally built boats. The
> original poster was building himself, free labor.
> Materials for a cold-moulded hull are cheap. Cheaper than good
> plywood. The mould can be built of low grade or scrap recycled
> material.
> DonB

Dear Don,

No Labor is "free" if your first love is to get out on the water.

Although the wood may be cheaper, the cost of the epoxy would likely
make the boat more expensive. Then there is the expense of the extra
tools you may need to prepare the veneer and hold it in place while
the glue dries.

My guess is that when Bolger and Payson developed the designs for
quick homebuilding they pretty much discounted these alternatives. A
big factor turned out to be that with all the beautiful curves you
can form with cold moulding, the end performance was not really
improved all that much. A huge advantage of straight and flat
surfaces is the ease as to how the interior can be finished and that
you get the maximum amount of interior room given the outer
dimensions.

Of course it is still an interesting concept. But I wonder why use
wood at all? Just use foam and cloth. Or do like canoeists, and build
a cedar stripper?

Nels
I would bet she means one-off professionally built boats. The
original poster was building himself, free labor.
Materials for a cold-moulded hull are cheap. Cheaper than good
plywood. The mould can be built of low grade or scrap recycled
material.
DonB


In reading Jones' "Boats to Go" or "New Plywood Boats", he quotes
> Susan Altenberger on cold molded construction. Apparently, she
calls
> it "gold molded construction." Does that tell you anything?
>
> Dennis Marshall, Grand Rapids,MI
I would guess it is one of the more labour intensive methods as well
as being costly in materials. The major benefit is the high strength
to weight ratio which is comparable to aircraft requirements. But how
many sailboats really need that level of performance?

Perhaps some sailers with deep pockets might think they do... Nels

--- In bolger@y..., "Peter Lenihan" <ellengaest@b...> wrote:
> > or,perhaps,prefers assembling her boats from material readily
> (cheaply) available at the nearest lumberyard(mega hardware store)
> without the added burden of dealing with alot of epoxy or the waste
> from the jig necessary for most well built cold molded boats.On the
> other hand,I ain't Susanne..........
> Sincerely,
> Peter Lenihan,amateur boatbuilder and chronic sufferer of the Peter
> Pan syndrome,along the banks of the mighty St.Lawrence.......
--- In bolger@y..., "proaconstrictor" <proaconstrictor@y...> wrote:
> --- In bolger@y..., "pseudodion42" <pseudodion3@a...> wrote:
> > In reading Jones' "Boats to Go" or "New Plywood Boats", he quotes
> > Susan Altenberger on cold molded construction. Apparently, she
> calls
> > it "gold molded construction." Does that tell you anything?
> >
> > Dennis Marshall, Grand Rapids,MI
>
> Yup, it tells you she doesn't spemd much time building boats.

or,perhaps,prefers assembling her boats from material readily
(cheaply) available at the nearest lumberyard(mega hardware store)
without the added burden of dealing with alot of epoxy or the waste
from the jig necessary for most well built cold molded boats.On the
other hand,I ain't Susanne..........
Sincerely,
Peter Lenihan,amateur boatbuilder and chronic sufferer of the Peter
Pan syndrome,along the banks of the mighty St.Lawrence.......
--- In bolger@y..., "pseudodion42" <pseudodion3@a...> wrote:
> In reading Jones' "Boats to Go" or "New Plywood Boats", he quotes
> Susan Altenberger on cold molded construction. Apparently, she
calls
> it "gold molded construction." Does that tell you anything?
>
> Dennis Marshall, Grand Rapids,MI

Yup, it tells you she doesn't spemd much time building boats.
In reading Jones' "Boats to Go" or "New Plywood Boats", he quotes
Susan Altenberger on cold molded construction. Apparently, she calls
it "gold molded construction." Does that tell you anything?

Dennis Marshall, Grand Rapids,MI