Drying plywood/foam sandwich to reduce moisture content?

[jmedclay]

Force drying Titebond II glued, plywood/foam/plywood sandwich with 2x perimeter closures to reduce moisture content of matrix. Necessary?

I built my floor as the description indicates. I'm going to seal the plywood underside surface with thinned epoxy and then paint it before attaching the walls. Once I do so any residual moisture, either wet glue or moisture in the plywood, will be trapped. It's been humid down here for the past months, only now starting to be a bit dryer. Also, I'm certain that plywood/foam contact isn't 100%, so perhaps there is some not-dry glue within. It will slow me down to do so, but it seems prudent to go through several sun bake or radiant heater cycles on both floor surfaces before sealing them up.

Any opinions on that? Would you think the normal daytime/night time temperature swings over the two weeks since gluing it up, would have been enough to have expelled any excess moisture that might have been present?

Thanks,
John

[Juneaudave]

I don't think it is necesary to run your panels through some cycles....but here's my two cents. First...I wouldn't normally thin the epoxy unless I'm missing something and second...put your epoxy on with temps cooling so that the epoxy gets drawn in. Epoxying in the sun and temps going up is a sure way to get outgassing.

[kennyrayandersen]

One thing about epoxy is that it’s an exothermic reaction and it doesn’t need to be heated up. I probably would have used it due to the predictability and available data on strength. Still, the Titebond is probably fine, and as long as it can get a wee bit of oxygen, it should set up. It will set up in the bottle if the lid isn’t on really good.

[jmedclay]

Thanks for the tips guys. One of the folks at Raka mentioned applying epoxy during falling temps too. Sounds like a good tip - I'll do it. Kenny, suddenly I realise that the trapped O2/Titebond-mass ratio in my floor is probably greater than when it's in the bottle; pretty thin smear of epoxy, O2 in the foam, O2 in the wood and whatever layer of O2 stayed in the assembly if/where contact wasn't complete.

I think it's time to seal it up (and the walls) and move on. I've got the walls and bulkheads all dry fitted up....it looks nice. I'll lay them flat, seal'em up and then glue them together. That will be pretty quick and then it's time for the roof!