It depends on whet kind of cedar strip construction.
If the boat is 'cedar strip composite', where there are structural glass skins,
the bond between the strips is not important. The strip are simply a core,
loaded in sheer. In this case, convenience and appraeance are what matters.
Yellow wood glue is commonly used. I prefer Titebond over Titebond II. It's
more easily sanded.

If the boat is of traditional strip plank construction, without structural
skins, the bonds between the planks are structurally important and should be
waterproof. Use epoxy or resorcinol.

KR & CA Hunter wrote:

Has anybody bought and built from a Compumarine plan? If so, could you
advise your experiences? I would like my next boat project to be a cedar
strip row/power boat and the John Clark plans look Ok on the web, but they
seem a bit expensive for what are essentially a set of hull templates.

Also, can anybody advise on what type(s) of glue are suitable for cedar
strip construction. Builders adhesive has been suggested. Here in
Australia the "Liquid Nails" product is sometimes referred to as builders
glue. Does anyone know whether this is the same product?

I would prefer to build without fasteners if possible, so any experience out
there would be appreciated.

Many thanks.

Ken

Jim Conlin wrote:
It depends on whet kind of cedar strip construction.
If the boat is 'cedar strip composite', where there are structural glass skins,
the bond between the strips is not important. The strip are simply a core,
loaded in sheer. In this case, convenience and appraeance are what matters.
Yellow wood glue is commonly used. I prefer Titebond over Titebond II. It's
more easily sanded.

I am afraid that is a major and very common misconception. I spent
quite a bit of time investigating strip composite construction before
committing to it for my hull. Besides the specifications from my
designer, I read everything I could find on the subject from Nicholson
to Gougeon to McNaughton. I also built several sample panels using
various construction methods and laminate schedules and tested them on a
CE friends precision testing press and various soak tests.

Some things I learned that need to be considered:

#1 The core needs to be as monolithic as possible. It is an important
component of a structural member. The larger the hull or the thinner the
core, the more critical it becomes. Stresses need to be transferred
between the skins as evenly as possible. If the core adhesive yields at
a lower pressure than the core material stress points develop at the
seams. While it may not be structurally critical these stress points
make maintaining a fair high gloss surface impossible.

#2 Laminating resins (including epoxy) are not totally waterproof.
While I was not able to get the MC up to the point that it would induce
rot spores, it did get high enough to weaken non-water resistant glues
like Tightbond.

3# The lighter the construction, the more important core integrity
becomes. At one extreme a glass sheathed stripper canoe or dinghy will
carry 90% of the stress in the core while a big hull like mine will
carry less than 50% in the core. In either case, scrimping on the strip
adhesive is false economy.

There is no real black and white in boat building. It is all shades of
gray made up of compromises. You can spend many hours and millions of
dollars trying to find a better way and still end up with a hull that
splits wide open with a little to much backstay tension. You can go
your own way, scrimping on costs and end up with a throw away boat or
you can follow proven modern construction techniques, save a lot of
effort and have a safe durable hull.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

Glenn, I defer to your research on larger boat structures. For the 28' tri I'm
building, i did use epoxy between the core-cell planking strips.

I should have qualified my statements to small boats which are not left in the
water.
On strip canoes, as the cross-grain strength of the 1/4" cedar is negligible, the
glass carries all of the 'thwartship loads. I've not heard of many strip canoe or
kayak builders using anything but carpenter's wood glue such as Titebond. My canoes
are kept dry, if only to keep the varnish out of the sun, but that's another thread.
I've not had any print-through of the yellow glue in the seams.

To Mr. Watt's comment about the difficulty of fairing epoxy-glued structures, I can
say that i end up shaping lots of wood-epoxy glue-ups and that their epoxy glue lines
offer very little resistance to a sharp plane, chisel, scraper or sandpaper.

Glenn Ashmore wrote:

Jim Conlin wrote:
It depends on whet kind of cedar strip construction.
If the boat is 'cedar strip composite', where there are structural glass skins,
the bond between the strips is not important. The strip are simply a core,
loaded in sheer. In this case, convenience and appraeance are what matters.
Yellow wood glue is commonly used. I prefer Titebond over Titebond II. It's
more easily sanded.

I am afraid that is a major and very common misconception. I spent
quite a bit of time investigating strip composite construction before
committing to it for my hull. Besides the specifications from my
designer, I read everything I could find on the subject from Nicholson
to Gougeon to McNaughton. I also built several sample panels using
various construction methods and laminate schedules and tested them on a
CE friends precision testing press and various soak tests.

Some things I learned that need to be considered:

#1 The core needs to be as monolithic as possible. It is an important
component of a structural member. The larger the hull or the thinner the
core, the more critical it becomes. Stresses need to be transferred
between the skins as evenly as possible. If the core adhesive yields at
a lower pressure than the core material stress points develop at the
seams. While it may not be structurally critical these stress points
make maintaining a fair high gloss surface impossible.

#2 Laminating resins (including epoxy) are not totally waterproof.
While I was not able to get the MC up to the point that it would induce
rot spores, it did get high enough to weaken non-water resistant glues
like Tightbond.

3# The lighter the construction, the more important core integrity
becomes. At one extreme a glass sheathed stripper canoe or dinghy will
carry 90% of the stress in the core while a big hull like mine will
carry less than 50% in the core. In either case, scrimping on the strip
adhesive is false economy.

There is no real black and white in boat building. It is all shades of
gray made up of compromises. You can spend many hours and millions of
dollars trying to find a better way and still end up with a hull that
splits wide open with a little to much backstay tension. You can go
your own way, scrimping on costs and end up with a throw away boat or
you can follow proven modern construction techniques, save a lot of
effort and have a safe durable hull.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

On Mon, 05 Jan 2004 04:00:06 GMT, Jim Conlin
wrote:

Glenn, I defer to your research on larger boat structures. For the 28' tri I'm
building, i did use epoxy between the core-cell planking strips.

I should have qualified my statements to small boats which are not left in the
water.
On strip canoes, as the cross-grain strength of the 1/4" cedar is negligible, the
glass carries all of the 'thwartship loads. I've not heard of many strip canoe or
kayak builders using anything but carpenter's wood glue such as Titebond. My canoes
are kept dry, if only to keep the varnish out of the sun, but that's another thread.
I've not had any print-through of the yellow glue in the seams.

Ted Moores recommends using only plastic resin glue in his canoecraft
book. That's what I used on the 16' cedar strip prospector canoe I
built. I found it easy to work with, sands nicely and doesn't show
glue lines. It's also quite cheap to buy.
Drew

I'm away from my books, but i recollect that he'd changed from using 'plastic resin' or
epoxy to yellow glue in later years.

Drew Dalgleish wrote:

On Mon, 05 Jan 2004 04:00:06 GMT, Jim Conlin
wrote:

Glenn, I defer to your research on larger boat structures. For the 28' tri I'm
building, i did use epoxy between the core-cell planking strips.

I should have qualified my statements to small boats which are not left in the
water.
On strip canoes, as the cross-grain strength of the 1/4" cedar is negligible, the
glass carries all of the 'thwartship loads. I've not heard of many strip canoe or
kayak builders using anything but carpenter's wood glue such as Titebond. My canoes
are kept dry, if only to keep the varnish out of the sun, but that's another thread.
I've not had any print-through of the yellow glue in the seams.

Ted Moores recommends using only plastic resin glue in his canoecraft
book. That's what I used on the 16' cedar strip prospector canoe I
built. I found it easy to work with, sands nicely and doesn't show
glue lines. It's also quite cheap to buy.
Drew

Drew Dalgleish ) writes:

Ted Moores recommends using only plastic resin glue in his canoecraft
book. That's what I used on the 16' cedar strip prospector canoe I
built. I found it easy to work with, sands nicely and doesn't show
glue lines. It's also quite cheap to buy.

I would imagine if one is using bead-and-cove strips the fit has to be
tight enough for palstic resin glue. If not shaping the edges for a
bead-and-cove fit would be a waste of time and money.


--
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"KR & CA Hunter" wrote in message
...
Has anybody bought and built from a Compumarine plan? If so, could you
advise your experiences? I would like my next boat project to be a cedar
strip row/power boat and the John Clark plans look Ok on the web, but they
seem a bit expensive for what are essentially a set of hull templates.

Also, can anybody advise on what type(s) of glue are suitable for cedar
strip construction. Builders adhesive has been suggested. Here in
Australia the "Liquid Nails" product is sometimes referred to as builders
glue. Does anyone know whether this is the same product?

I would prefer to build without fasteners if possible, so any experience
out
there would be appreciated.

Many thanks.

Ken


I just use the woodworkers PVA glue on my strip kayaks. It cleans up with a
wet sponge prior to setting, sets clear, is easy to sand down if needed.
However it will not hold without a clamp or staples until dried. Once dried
it will hold the strips in complex curves - I was surprised at first just
how the whole kayak shape stayed snug onto the mould when I removed the
staples. Once covered in epoxy and glass it does not really matter what glue
was used between the strips.

If you are desperate not to staple there are a few designs for clamps, or
just buy some shares in Gaffer Tape and use rolls of it to pull the planks
tight. I find that the staple holes close up and are so small as to be
almost invisible unless you go looking.

IMHO avoid using epoxy as the gluing medium - its too hard and when you fair
the hull/deck you'll end up with ridges where the cedar sands down faster
than the epoxy.

Have a look at www.oneoceankayaks.com which has an enormous amount of detail
on wood strip construction, epoxy, glassing.

--
www.bribieisland4x4hire.com
VW Kombi Camper Buy Backs
Landcruiser Troopy - Toyota Hilux Crew Cab
Mitsubishi Pajero - Landrover V8 Swag Camper

If you can get a copy of a book called: "Building the St. Pierre Dory" by
Mark White it details building 20+ foot boats using the strip plank method.
Mr. White does an impressive job with pictures and loads of information on
the entire process including which glues work and why....I would be happy to
forward excerpts from my copy if you would like.
regards, mike
"KR & CA Hunter" wrote in message
...
Has anybody bought and built from a Compumarine plan? If so, could you
advise your experiences? I would like my next boat project to be a cedar
strip row/power boat and the John Clark plans look Ok on the web, but they
seem a bit expensive for what are essentially a set of hull templates.

Also, can anybody advise on what type(s) of glue are suitable for cedar
strip construction. Builders adhesive has been suggested. Here in
Australia the "Liquid Nails" product is sometimes referred to as builders
glue. Does anyone know whether this is the same product?

I would prefer to build without fasteners if possible, so any experience
out
there would be appreciated.

Many thanks.

Ken