: Hi James,
: I think the epoxy paint would be a better choice.

: Mike Savage

I agree, if choosing between those 2 alternatives.
Epoxy paint can be pricey- 'real' epoxy resin might not be much more expensive, and the 'leftovers' can be very useful.
If there are any voids in the plywood, they can cause a problem. Seal/fill the edge voids at a minimum, I think.
I used 'birch plywood' (the big-box, non-'Baltic' type) once on a speaker project. Never again......