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Michael Daly Michael Daly is offline
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First recorded activity by BoatBanter: Jul 2006
Posts: 159
Default Shortening a kayak?

Wm Watt wrote:
Michael Daly wrote:
You don't get it, you never will. I'm a structural engineer and I know bad
designs when I see them. Asymmetric joint construction is not good design.


Gee, I got an "A" in engineering math at the UofT but note of that is
relevant to the discussion.


There's a lot more to structural engineering than a bit of math. The essence of
structural engineering is stress analysis and proper design within safety limits.

On plywood panels with epoxy adhesive the plywood breaks before the
butt join. It's stronger than the rest of the hull.


Butt joins on fiberglass and butt joins on plywood are not the same thing. The
difference in strength between the base material and the adhesive is
significant. Plywood is thick and weak, fiberglass is thin and strong. Lapping
a tape over one side of a plywood joint is not going to have the same effect as
doing the same with fiberglass.

As I've already pointed out - if single taped butt joints in kayak seams were
sufficiently strong, we wouldn't see so many failures and so many paddlers
condemn the manufacturing technique. If the joint was sufficiently strong, it
wouldn't be so sensitive to labour and quality of construction as you have claimed.

Mike