: Hi,
: I wonder what would happen to unvarnished epoxi. The boat will be used in
: rivers and lakes, here in Germany mostly in the shade with moderate temp.
: Is it only the look that suffers? I thought it would be easier to apply
: repairing coats later on if I don´t have to sand away the varnish first.

: Thanks Joaquin

Epoxy requires protection from ultra-violet light. It will turn white and degrade with time and exposure. Marine varnishes are typically used by the kayak building crowd because they offer good UV protection, hold up best in a marine environment, and can be applied with nice results using only a foam brush. Regular paddlers will revarnish their kayaks (or at least the bottom of their hulls) every off-season. The varnish is sanded off only where epoxy repairs are necessary. After the epoxy is fully cured and sanded, the varnish on the unrepaired surfaces is just wet sanded to provide tooth for the new varnish to adhere.