Ama Ballast Tank Considerations

About a third of the ama volume will be taken up by twin ballast tanks.  The ballast water is held by the hull and decks directly instead of in discrete tanks. This will probably be one of the most abused areas of the boat.  The tanks will rarely be completely dry.  Instead they will be more like a hot, humid washing machine bouncing across the waves. It's pretty important that these tanks are completely waterproof.

Gougeon has published some Guidelines for Wood/Epoxy Composite Tanks.  To summarize,

• Tanks should have 5 or 6 coats of epoxy
• The epoxy should be slightly resin rich to reduce microscopic amine deposits trapped in the cured mix.  The amine could act as a tunnel for water.
• The tanks should be post cured to at least 120F for 4 to 8 hours.
• Care to avoid amine contamination should be taken in mixing and cleaning cured surfaces.

Since this is non-potable water, I am planning on using 422 Barrier Coat Additive in the last couple of coats.  I could not find much information on 422's effects on bonding strength, so I will hold off on using it until the ama has been assembled.

The panels are currently up to four coats on the interior and are about ready for assembly