# Deep scratch to GRP roof - what should I do?



## H1-GBV (Feb 28, 2006)

My lovely white GRP roof came off second best to a metal bolt protruding from a gutter - a long scratch (1cm wide) which has gone through to the matt coat (no obvious damage) for about 20cm. The damage is on the corner of the roof line, so virtually invisible from ground level.

My local MH dealer will "fix it" for about £250, including matching some spray paint.

Can I just fill it with Plastic Padding (£5), spray it with Holts white paint(£2)? I have seen previous references to "gel repair" but our Halfords doesn't stock it - is it vital?

Many thanks in advance.


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## 97993 (Mar 5, 2006)

after spending many an hour searching for a gel coat repair system
95% of repairers want to fill and spray paint, this seems the next best thing to a "proper" repair, if you are going to DIY research and choose your filler well it is your roof after all, the very last place you want water ingress, fibre glass resin may be the most suitiable, poured in and allowed to set prior to sanding/ Primer and top coat, any better/alternative suggestions will follow in due coarse
Geo


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## davoscar (Feb 28, 2006)

Hi
I have done a similar repair on a Clubman roof. You really need a Gel coat filler not just plastic padding (although plastic padding make it!) The most difficult bit is a paint match. GRP repairers colour the gel-coat itself and it is an art to get an exact match. I had a similar repair done in Plymouth by a guy recommended by Marquis - he was brilliant and you literally could not see the repair - cost about £100. If you go down the DIY route its not difficult to get the repair looking good (plenty wet/dry and patience) but the colour match is tricky. Some Auto paint people will supply an aerosol exact match if you know the Manufacturers colour - white is not white of course there are dozens of them. Good luck David Towsure stock Gel coat - they also have a website...


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## gaspode (May 9, 2005)

Got to agree with geo - as usual. Pour resin into the gouge, allow to harden off then cut back with wet&dry until smooth and paint with a self etching primer followed by aerosol spray. If it's on the roof and appearance is secondary this should be best for waterproofing.

Just another thought - if appearance doesn't matter, fill the gouge and half an inch each side with Sikaflex 512 - or another polyurethane sealant. Should seal and remain flexible - easier but the repair will be easily seen.


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## H1-GBV (Feb 28, 2006)

Thanks for the advice so far. A circuitous route via ebay took me to TOMPS in Sutton Bridge, about 50 miles away. They offer clear, and WHITE, gelcoat products - "highly thixotropic" - at approx £7.50 per kg +VAT. 

I think a visit might be in order, as this will be much cheaper than the local dealer.

However, there are snippets about "flowcoats" as well. Has anyone used similar products?

Many thanks again.


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## 97770 (Feb 19, 2006)

Hi plastic padding do a gel coat/fiberglass filler for boats around £7.00 a small tube 8O but good stuff i used it on my boat on the water line and on a camper roof and it worked fine ..

FORDY


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## GROUNDHOG (Mar 7, 2006)

I can confirm that, try any good marine chandlery and you can get hull gel coat repair products in small amounts that are ideal for fixing small scratches... and on the basis most boats have white hulls the colour may not be an exact match but near enough and waterproof!


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## 92859 (May 1, 2005)

Greetings,

I have done many repairs to GRP boat hulls and superstructures and have used white gel coat available from many boat chandlers, Plastic padding do a small pack that is suitable for small damage areas.

Do not use filler because polyester filler is porous and you then have to paint it anyway.

Clean the damage with acetone or cellulose thinners then once dry using a small plastic spatula or broken credit card, fill the damaged area so that it is just proud of the surface. once sufficient material is on, cover the repair with some plastic film or tape this will prevent the surface being tacky when it dries.

Once the repair is cured use a proprietary brand of wet and dry paper to flat the gel coat down, use a small block of hard wood or plastic to put the paper around this should keep the paper square with the surface, use a constant supply of water with a little washing up liquid in it. do not use higher than 320 paper, then go down to 600 then 1000 or 1200, once the surface is level you can use some rubbing compound to smooth and polish the area.

There are many shades of white but once blended in, if it is on the roof line it should not be noticed, if you are not happy with the colour match you can spray the surface, but at leat the damage is repaired properly, if you are going to spray over it, first flat off with 1200 wet and dry then prime first before painting otherwise the paint may flake of over time.


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## chapter (May 1, 2005)

try a company called seaglass they supply the surfboard shapers with all things glass gel and pigments


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## H1-GBV (Feb 28, 2006)

Many thanks for everyone's help.

I went to a local (Norwich) GRP company and bought white gelcoat (1kg) + hardener for £15. The helpful proprietor climbed on the roof and confirmed the matt coat was OK, so home for a sanding and clean up. A little of the liquid goes a long way - including onto the carpet via a piece which fell to the ground and got walked on by me. Perhaps the tube of Plastic Padding from Towsure (and others) would have been easier but I wanted to do it today.

However, I am happy that the roof is watertight and fully protected, although there will be quite a bit of smoothing and re-filling to do before the job is complete.

Again, thanks for the help - I'd better get the wallet out and become a subscriber!  

Gordon


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## geraldandannie (Jun 4, 2006)

H1-GBV said:


> Again, thanks for the help - I'd better get the wallet out and become a subscriber!


Kerrr-ching!

Well done, Gordon. You won't regret it, I'm sure.

Glad you were able to fix it.

Gerald


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