AMPowers wrote:

A tale of two ****ties:

He used iron nails
to attach the lid to the box, sealing it with silicon window sealer.

Oh my gosh!!!

I used many layers (the final wall thickness was 3/8") and
added a powder to the epoxy (recommended by West Systems) specifically
for creating vapor/liquid barriers.

Ahh, this sounds more like what most advise strongly.

Given all the options, this probably wasn't the cheapest or easiest, but
it did fix the problem.

Yes, exactly what I've been thinking. Stuff a palstic tank under the V-
berth and foam it in sounds like an inexpesive and quick
way................ I only wish I had that option. After an eight year
remodel on a house built in 1905 my wife cringed when I got the boat.
Her reply when I asked her thoughts on getting a sailboat were, " I
dont want to whittle a mast before we can go for
sailing...................................."

Time to go whittle a waste tank.
Bob



Hope this helps.

Robb