Gel coat repair

[inkslinger]

We got caught out in a terrible hail storm on a recent trip. Our Trillium held up well, but the gel coat was cracked in a few spots (the underlying fibreglass seems undamaged).


I also noticed the previous owner had patched a few similar issues with clear silicone, so I'll need to remove the silicone and redo those repairs as well.



What's the best/proper way to repair a cracked gel coat?

[Bolerpete]

Hi there....sorry to see your hail damage.... but not all is lost.
What you will need is some elbow grease, some neutral base gel coat, MEKP hardener, and some pigments (ie. white, yellow, tan, depending on the colour of the gel oat on your trailer). If your trailer is a stark white, you might get away with white gelcoat, but many rv “whites” are off whites.
You will have to remove all of the gelcoat spider cracks by sanding down to fibreglass. It is always best to match a large patch rather than try to match the areas where the cracks are. Because the fibreglass is intact and the gelcoat cracked as it is harder and brittle by comparison, you do not need to worry about structural fiberglassing in your repair. Just use a sander to sand down the area to the fibreglass. The outsides of the circular area should be feathered so when you overlap gelcoat over this feathered area it will seamlessly blend in colour when you sand and buff.
Use acetone as a quick wipe to clean the area after sanding and between coats of gelcoat. You need to acetone between coats of gelcoat, but no need to sand.
Once you have built up the gelcoat(above the original and surrounding area), start sanding with 120 grit, then 180, 220, 400 wet, 600 wet, 1200 wet, 1500 wet, and lastly buffed with gelcoat wax (I use 3M brand, heavy oxidation type).
There are gelcoat repair videos on YouTube that discuss these things and more.
It seems like lots of work but I have done these repairs all over my Boler and I would say that the bulk of the grunt work could be done in 3 hours for your repair. Make sure you take the time to mix your colour so that it matches perfectly.......this may take an hour....but time well spent. Then in small batches, mix your tinted gelcoat with hardener.
Best of luck- not to worry, your natural mishap only cost you about 5 hours.
Pete

[Thomas A Cronquist]

This can be easily fixed. Look under spider crack for a kayak.
Good luck.
Tom

[inkslinger]

Thanks for the detailed reply! This is a big help.

[LittleJohn]

Great tutorial Pete thank you. Do you think it's possible to find a good belt sander under 50 from that site?

I am limited on budget for tools because I have gone over on my materials budget.

[k0wtz]

You are the man. very nice write up

thanks

bob

Originally Posted by Bolerpete

Hi there....sorry to see your hail damage.... but not all is lost.
What you will need is some elbow grease, some neutral base gel coat, MEKP hardener, and some pigments (ie. white, yellow, tan, depending on the colour of the gel oat on your trailer). If your trailer is a stark white, you might get away with white gelcoat, but many rv “whites” are off whites.
You will have to remove all of the gelcoat spider cracks by sanding down to fibreglass. It is always best to match a large patch rather than try to match the areas where the cracks are. Because the fibreglass is intact and the gelcoat cracked as it is harder and brittle by comparison, you do not need to worry about structural fiberglassing in your repair. Just use a sander to sand down the area to the fibreglass. The outsides of the circular area should be feathered so when you overlap gelcoat over this feathered area it will seamlessly blend in colour when you sand and buff.
Use acetone as a quick wipe to clean the area after sanding and between coats of gelcoat. You need to acetone between coats of gelcoat, but no need to sand.
Once you have built up the gelcoat(above the original and surrounding area), start sanding with 120 grit, then 180, 220, 400 wet, 600 wet, 1200 wet, 1500 wet, and lastly buffed with gelcoat wax (I use 3M brand, heavy oxidation type).
There are gelcoat repair videos on YouTube that discuss these things and more.
It seems like lots of work but I have done these repairs all over my Boler and I would say that the bulk of the grunt work could be done in 3 hours for your repair. Make sure you take the time to mix your colour so that it matches perfectly.......this may take an hour....but time well spent. Then in small batches, mix your tinted gelcoat with hardener.
Best of luck- not to worry, your natural mishap only cost you about 5 hours.
Pete

[k corbin]

Originally Posted by LittleJohn

Great tutorial Pete thank you. Do you think it's possible to find a good belt sander under 50 from that site?

I am limited on budget for tools because I have gone over on my materials budget.

ask around in your neighborhood or at work or your group of friends, you can likely borrow a belt sander from someone. Of course they are being sold by owners on sites like facebook marketpace and craigslist. Then you can turn around and sell it for what you paid for it and have free use of it other than buying a sanding belt. You can also find them in pawn shops and then sell it later on craigslist.

[charlsara]

A belt sander can be very aggressive and do more damage than good if you are not experienced with one. I suggest a random orbital.

[thrifty bill]

+100 Belt sanders are very aggressive.

+10 on used tools. About half my tools were acquired used. Not only cheaper, but greener too. Lots of lightly used tools out there. I just donated some to Habitat Restore.

[trilliumdan]

Good idea