Purebond plywood

[Global Nomad]

I've got a sample of Purebond veneer core hardwood plywood from Columbia Forest Products that I need to run a boil test on. Anyone ever use the stuff for frames?

 

I'm going to sneak another question in -- What width & length do I need for skin material for a Ravenswood? I'm starting to collect materials.

 

Thanks.

[Kudzu]

Unless you plan on boiling the boat the boil test doesn't tell you much. Baltic Birch doesn't doesn't pass the boiling test but it is has proved to be a really good wood for these boats.

[PAR]

The boiling test is intended to simulate years of water immersion and wet/dry cycling. In terms of adhesive evaluation, it's does warrant some questioning, but since all adhesives (and glues, for those that know the difference) are rated to this standard, it's important as a reference. Interestingly enough, epoxy isn't able to pass the type 1 WBP test, which means the US Navy can't consider it waterproof, but unless you park over active underwater volcanoes, you'll find marine grade epoxies are indeed waterproof. TiteBond III is considered waterproof as it does pass the type 1 WBP test, but it does so just barely (I'd never use TiteBond on any submerged part), reinforcing my (and Jeff's) issues with this test. The test is just for comparative use, with some interpretation necessary as well.

[Global Nomad]

Thanks, PAR, that's helpful info. It lasted an hour in the pot (which is far longer than I plan on boiling the boat), seems to have a good core, and I can get it locally for less than $45/sheet so I'm going to give it a shot.

[PAR]

How many boil/cool cycles did you toss at it? This is the key to the test's success, which strains the wood's grip on the adhesive.

[Global Nomad]

Just 1. I figured a real test would be more and longer but thought surviving an hour would be good enough for an interior frame on a kayak.