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