: This deflection does not account for all the damage only on the glue lines.

I think that because of the way the materials behave it probably does. Wood is a cellular structure bound by lignin over its entire length and width, which is how it develops its strength. Glue doesn't develop any strength on its own, and because of this it will fail 100% of the time in an improperly fitted joint when exposed to a load. When it fails it will put stress on the fiberglass at the point of failure and not somewhere else.

: If damage happens only on glue lines then maybe it has something to do with
: the glue, ya think?

Yes, I do, but it's not the glue's fault. The fault lies in a poorly fitted joint in the core, which is expressed as strained fiberglass at the point of failure. I think they're saying that if you can reinforce the core to prevent its failure you can decrease the risk of straining the fiberglass.

: I wonder how many of their tech people have worked exclusively with clear
: lay-ups on stripper construction for twenty years.

The first gentleman I spoke to has taught boatbuilding classes for 15 years, and I would assume that he began building boats before he began teaching the subject.

Gougeon Brothers has an extensive engineering and testing program, and they publish all of their results. They have produced a literal library of texts on building with epoxy, including the standard reference on building boats with epoxy. They also publish a technical magazine that releases new information as it becomes available between updates of their texts. The magazine includes technical articles by end users of the products, including professional builders who have more than 20 years of experience with clear layups.

I have worked in both independent test labs and manufacturer's test labs, and the ability they have to test their products is way beyond what any professional or home builder can duplicate. If you can put together a test to illustrate your experiences with different glues and layups or a set of case studies of actual failures with critical analysis I would really like to see it, and I'm sure it would be important and valuable to a lot of people. You should try and get the results published somewhere. It may be a unique problem that manufacturers have not encountered and something that can be addressed once brought to light, which will benefit everyone who uses epoxy, West Systems or not. Nobody wants to have this happen to a boat they've spent months working on, and professionals REALLY don't have the time to rebuild boats that develop this problem once they get out to the customer.

: Believe what you choose.

Yep.

m