Don't have small piece of marine plywood and decided to water-seal a regular fir plywood (Thompson Seal) and then put on epoxy. Part is used for sail rig mount and will always be above the waterline, albeit under some splashes. Instructions for Thompson Seal (content unklnown, but I suspect is similar to tung oil) say that oil painting is possible after 5 days. Did anybody try epoxy after such kind of "seal"?