Originally Posted by camaraderie
Wood (marine ply or Teak) is fine but once you have it "fitted" well to the hull form then coat it with epoxy to avoid deterioration and then bond it to your hull using 3M 4200 or the equivilent. Note that the screws into the wood are just to keep it from turning. the real strength of the application is from the compression of the screw threads.
Cam the screws on flanged sea cocks are meant to go all the way throught he hull and they are not designed to be "wood screwed" into the backing plate. The idea of a flanged through hull is that you have multiple fastening points including the through hull and the three silicon bronze machine bolts..