Patch Gel Coat with Polyurethane paint

[Michael Simmons II]

hello, I have a boat I’m doing a repair on, and was wondering if I could use a polyurethane paint to patch and fade into the old gel coat. It’s about a 24”x6” repair, the boat has a DK blue gel coat. Or will the polyurethane paint not match/fade correctly into existing gel coat?

 

[Blueknarr]

Welcome

I have 25 years of experience as an industrial painter, working primarily with polyurethanes. A few years ago I started to focus on the maritime. I now run the fiberglass repair department of a small boat repaire facility.

Gelcoat has many advantages and some problematic issues. It is not known for having high color fidelity (it changes quickly). Matching dark colors is difficult. The repair gelcoat is likely to "fade" differently than the original. A polyurethane touch up will have "ring around the repair" from the get go.

Resins shrink. However fair you your repair is initially, it will diminish in a year. I like to give the structural repair a month to shrink before starting the color repair.

IMO, your best bet for a long-term invisible repair would be an innitial gelcoat. Followed by repainting in a year or two.

Best of luck

 

[Mr Efficiency]

For starters, aside from the problems mentioned by Blueknarr, where do you get this polyurethane paint ( assuming you are talking 2 pack) that would be a colour match for the gelcoat ? You can't, in practical terms, there are just a few factory mix colours, and paint tinter can't be used to alter it. If you are talking one pack, of course that does not apply.

 

[Mr Efficiency]

For starters, aside from the problems mentioned by Blueknarr, where do you get this polyurethane paint ( assuming you are talking 2 pack) that would be a colour match for the gelcoat ? You can't, in practical terms, there are just a few factory mix colours, and paint tinter can't be used to alter it. If you are talking one pack, of course that does not apply.