How to Refinish Worn Gelcoat

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Centurion
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How to Refinish Worn Gelcoat

Post by Centurion » Tue Jun 14, 2022 2:43 am

Hope I'm not duplicating previous threads but I couldn't get "search" to find anything on this.

I have an Elliott Bay hull ~ 25 years old with black hull, beige deck, and red below the waterline gelcoat. What is the best way to restore this finish back to close to new?? New Gelcoat or paint over the Gelcoat?

Also, I live in the central NY State area. Any thoughts on shops or marina that could do this for me?
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Re: How to Refinish Worn Gelcoat

Post by TahoeSteam » Tue Jun 14, 2022 2:50 am

If there's no checking (cracking) in the gelcoat you may be able to get away with a robust buff and waxing. Mechanical variable-speed buffer is the way to go.
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PeteThePen1
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Re: How to Refinish Worn Gelcoat

Post by PeteThePen1 » Tue Jun 14, 2022 2:21 pm

When Frances Ann came back from a year afloat in the Lakes the gell goat had been adopted by a plethora of fresh water organisms. A good scrub failed to remove them and the shiny original white was gone. I resorted to a two pack white boat finish put on with a mini roller whilst dressed in respirator and coveralls. The finish was good, though matt. Apparently one could get another product in the range to add a gloss finish. I was not bothered so dod not try it. Sorry not to offer the product name but I have not kept the file with all that in due to downsizing.

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Re: How to Refinish Worn Gelcoat

Post by barts » Tue Jun 14, 2022 6:53 pm

The marine two-part polyurethane finishes are very good, hard and long lasting. My brother has used the Interlux two part systems with excellent results; hand rolling and tipping; many have asked if he sprayed the finish. As always, surface prep is critical so follow the directions.

Note also that chemical vapor respirators are required for these paints; spraying them really requires a positive pressure system.

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Lopez Mike
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Re: How to Refinish Worn Gelcoat

Post by Lopez Mike » Sat Jun 18, 2022 1:05 am

Having fought the whole Gel Coat issue to a standstill over thirty years of sailboat ownership, I have some observations.

In order:

A: Try buffing first. There are several grades of buffing compound and I have been repeatedly surprised at how well this method can work. It is the cheapest and does the least long term damage.

B: 400 grit wet or dry sandpaper followed by method A above. You can do this several times over the life of the gel coat before you arrive at the underlying glass resin at which point you can try C.

C: 80 grit and an orbital sander and remove the gel coat followed by either single part polyurethane (Brightside) OR two part urethane with it's attendant potential death toll and difficulties. I think two part stuff is for pros. My respirator leaked once and I had heart palipitations and blurred vision overnight. The best way to apply single part urethane is to roll it on followed right behind by your friend with a brush to tip it out. I did my launch topsides and bottom this way. Worked great once we got the roller paint loading right.

I removed the gel coat from all of the underwater areas of my 36' sailboat with a sander. Took a couple of afternoons. I hooked up my shop vacuum to the sander.

Option A is the easiest and cheapest. Two part stuff can look great and outlast the rest of the hull but but the consequences of screwing up for either you or your hull are significant.
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Re: How to Refinish Worn Gelcoat

Post by Kelly Anderson » Sat Jun 18, 2022 2:30 am

One part Interlux Brightside is excellent paint, and it's pretty easy for an amateur to get a sprayed equivalent finish using a roller and brush.
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