Join Date: Feb 2000
Location: Annapolis, Md
Thanked 449 Times in 379 Posts
Rep Power: 10
polyester vs epoxy resin for underwater gelcoat
There is absolutely no reason to gelcoat underwater repairs. Epoxy is a very superior material to polyester for use on underwater repairs for all reasons. Better adhesion and impermiability, easier to work over time, etc. If you feel that you absolutely need to have a gelcoat finish over the repair, then use vinylester resin which is a close second to epoxy but which will accept gelcoat.