Black Gel Coat Repair Lessons

[Markk]

I’m repairing screw holes left from previous owner. They had 5200 on them, but I wanted to fix them permanently.

Sanded surface to 400 before applying Spectrum paste. Took 3 coats to get holes completely covered.

After gel paste cured I sanded with 220/400/600/800/1000/1500. Followed up with fast cut polish on an orange pad and regular polish on the blue pad.

In hindsight, I stopped sanding at the 220/400 levels too soon as I feared I would sand through and reveal the holes I wanted to cover. This was my mistake. Lesson learned if you can see inconsistencies at the sanded stage, they will follow you to the glossy stage. Secondly, the inconsistencies were most visible when dry. When the surface was wet they were much more hidden.

 

[Markk]

Here are my supplies:
-Spectrum gel paste kit matching factory color
-Paint stick split into two
-Salsa cups from Taco Bueno
**mix small amounts of gel paste. ¼ bottle or less. It goes a long way and sets up faster than you’ll expect
-Plastic squeegee from recent vinyl application
-Acetone
-vinyl waterproof tape
-bright shop light
-Wet sand paper 220/400/600/800/1000/1500
-polisher with two levels of polish

 

[scokill]

Black will show imperfections for sure. White is a piece of cake.

 

[tdonoughue]

Even at that, I bet you are the only one who will notice that. From 10 feet away or in the water, no one will see anything but a perfect boat.

Nice repair.

 

[MidnightRider]

Nice repair. Getting ready to do a repair on black myself. What brand and type of polish did you use. Also, orange and blue pads? Is there a brand that has two different pad variants in orange and blue? Wouldn't happen to have links to these polish products would you? Thanks.

 

[Jameson Clark]

Glad to see this thread. About to start a patch on mine as well.

 

[Markk]

Ardex VG Marine Fast Cut Polish

Ardex VG Marine 2408 Fast Cut-Swirl Free Compound

Fast Cut, Swirl Free Vanishing Grit Compound, 800 Grit to a swirl free finish in one easy step.

www.ardexautomotiveandmarine.com

Summit Racing All in One compound/polish

https://www.summitracing.com/parts/sum-22-983?seid=srese1&gclid=EAIaIQobChMIqqr99Yqy6QIV2-KGCh2fMA-uEAQYASABEgLN5fD_BwE

Harbor Freight Bauer Polisher

5.7 Amp 6 in. Short-Throw Random Orbit DA Polisher/Sander

Amazing deals on this 8Mm Random Orbit 6In Da Polisher/Sander at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Orange Cutting Pad

Harbor Freight Tools – Quality Tools at Discount Prices Since 1977

Harbor Freight buys their top quality tools from the same factories that supply our competitors. We cut out the middleman and pass the savings to you!

www.harborfreight.com

Blue Polishing Pad

Harbor Freight Tools – Quality Tools at Discount Prices Since 1977

Harbor Freight buys their top quality tools from the same factories that supply our competitors. We cut out the middleman and pass the savings to you!

www.harborfreight.com

 

[MidnightRider]

Ardex VG Marine Fast Cut Polish

Ardex VG Marine 2408 Fast Cut-Swirl Free Compound

Fast Cut, Swirl Free Vanishing Grit Compound, 800 Grit to a swirl free finish in one easy step.

www.ardexautomotiveandmarine.com

Summit Racing All in One compound/polish

https://www.summitracing.com/parts/sum-22-983?seid=srese1&gclid=EAIaIQobChMIqqr99Yqy6QIV2-KGCh2fMA-uEAQYASABEgLN5fD_BwE

Harbor Freight Bauer Polisher

5.7 Amp 6 in. Short-Throw Random Orbit DA Polisher/Sander

Amazing deals on this 8Mm Random Orbit 6In Da Polisher/Sander at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Orange Cutting Pad

Harbor Freight Tools – Quality Tools at Discount Prices Since 1977

Harbor Freight buys their top quality tools from the same factories that supply our competitors. We cut out the middleman and pass the savings to you!

www.harborfreight.com

Blue Polishing Pad

Harbor Freight Tools – Quality Tools at Discount Prices Since 1977

Harbor Freight buys their top quality tools from the same factories that supply our competitors. We cut out the middleman and pass the savings to you!

www.harborfreight.com

Thanks!

 

[rad1026]

Not sure if Markk is still around, but I have a similar repair I'm going to do this weekend. I have the spectrum matching white gel coat paste and a couple scratches and two small, dime size indents like he is showing in his initial post. His damage was on a flat surface, mine is on the rear rounded area at the starboard transom. My question to Markk or anyone that has done these repairs is should I smooth the edges of the indents before I fill them or leave them as is, kind of jagged?

 

[tdonoughue]

Sorry for the late reply here. Hopefully it is in time to do some good....

It is really less about whether it is jagged or not and more about how big the gap is you are filling. If it is a scratch, you need to take a Dremel and widen that (about 1/8" at least) in order to have enough that the new gelcoat can stick to the sides and the base (the fiber or glass below). Otherwise, what you put in there will just pop out again. It is scary--it will look like you are making things worse. But that is what is needed. Jagged is ok, but thin is bad.

Your challenge working on the corner is going to be at the sanding step. Be sure you use a block and go very lightly and mostly on the flat surfaces. Remember that as you sand the corner, you will take off WAY more material than you did on the flats. So go gently. It is easy to take off more; much more difficult to put some back.

Hope that helps.