William_H
Well-Known Member
We have to go back to the name "Gel Coat". It comes from the concept that the gel coat is applied first to the mold and allowed to Gel. ie not really hard but getting firm from the original liquid. In this state it will mechanically resist the glass fibres going through to what will be the outside of the hull but is still chemically active to make an excellent chemical bond to the resin in the fibre glass. Polyester resin is excellenty at chemical bonding to itself but not the best at mechanical bonding. Yes it will but partly due to shrinkage on hardening will not grip as well as epoxy or similar. Hence once a polyester GRP boat is built and cures any further polyester in any form will rely purely on mechanical bonding which is not the best.
So on an old boat far better is epoxy but that is no good in UV conditions. best is 2 pack polyurethane paint which is a resin or one of the excellent paint schemes.
So from theory I can't imagine why anyone would use gel coat or flow coat polyester resin for refinishing an old boat. I presume just because people have this fixation to replace what was original.
What OP needs to consider is further damage to the boat. I have never seen a boat which is used that is imune to scratches. A paint scheeme is best for touch up. Preferably a brush on scheme. I do however endorse the concept of just rely on plishing old gel coat for as long as possible. good luck olewill
So on an old boat far better is epoxy but that is no good in UV conditions. best is 2 pack polyurethane paint which is a resin or one of the excellent paint schemes.
So from theory I can't imagine why anyone would use gel coat or flow coat polyester resin for refinishing an old boat. I presume just because people have this fixation to replace what was original.
What OP needs to consider is further damage to the boat. I have never seen a boat which is used that is imune to scratches. A paint scheeme is best for touch up. Preferably a brush on scheme. I do however endorse the concept of just rely on plishing old gel coat for as long as possible. good luck olewill