My understanding of most birch cabinet plywood is that it isn't built with waterproof glue (though I could easily be misinformed). Since you'll presumably be using the boat in somewhat damp conditions, this could prove to be a bit of a problem. You're right that end grain soaks up a lot of fluid - whether epoxy or water. Personally - no matter what I coated it with - I'd rather use really ugly exterior grade plywood than really pretty interior grade. It'll be hidden inside the boat, in any case.

But, maybe your birch plywood has waterproof glue? I do hope so, since cutting out those frames gets to be a chore . . . .

Good luck!
Dave

: I've cut out two of the five plywood cross sections for my interpretation of
: Brian Schulz's F1 with Tom Yost's construction technique and will have the
: rest finished by the end of the night. In a total lapse of judgment, I
: ended up buying Birch "cabinet grade" plywood rather than
: exterior grade. (It was too hard to resist the beautiful veneer at a much
: lower price!)

: My logic at the time went something like "I'll slather on some epoxy to
: seal it, and get a the beauty and thickness of this wood for cheap."
: I'm wondering how exactly I should go about sealing it though. Epoxy would
: probably be ideal, but it's expensive and I can easily imagine the low
: density end grain drinking up a few coats. Is there something which would
: work as well but is a lot cheaper? I don't really have any experience with
: wood finishes. I'm thinking maybe a small can of that clear hard wood
: finish could suffice? It might be called "polycrylic" or
: something. Is there a hardware store chemical which would seal as well as
: epoxy? If it comes down to it, I'll take superior protection over price,
: but if they basically perform the same, I'll save those pennies.

: Thanks,

: Mike Collins