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Mr. Gromis
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tooling-gel coat ate through the clear paint and primer underneath so my question is which paint can I use that won't be eaten by-tooling-Gelcoat? help
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torsten Ker
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The tooling gelcoat is polyester based with hight styrene content, basically it acts like a paint stripper.
The only coating suitable for these kind of gelcoats are 2k, basically paint with hardener which have high chemical resitance
I did the same mistake a year ago
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Mr. Gromis
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Group: Forum Members
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+xThe tooling gelcoat is polyester based with hight styrene content, basically it acts like a paint stripper. The only coating suitable for these kind of gelcoats are 2k, basically paint with hardener which have high chemical resitance I did the same mistake a year ago so i bought EASTWOOD'S 2K AEROSPRAY™ CERAMIC CHASSIS BLACK and EASTWOOD'S 2K AEROSPRAY HIGH-GLOSS CLEAR on the internet net its 2k thank you for pointing me in the right direction
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Warren (Staff)
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I assume they are rattle can sprays? You may still have problems as most 2k sprays are still solvent laden.
2k through a professional spray gun is the way to go ideally if you use paints.
Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant
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Hanaldo
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Yeh, unfortunately still a lot of traps to run into, even with 2k. Ideally you would do a thorough bake at 80° for 2 or 3 hours to fully cure the paints, and even then some of them are just vulnerable to styrene.
Worth a try, they may work - but do a test before you commit yourself!
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Warren (Staff)
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Generally we would advise people to avoid paints where possible because of these kinds of issues. And sometimes even 2k paints will come off in the mould, not because of release issues but because the bond to the substrate isn't always that strong.
We tend to recommend products like our Pattern Coat Primer and High Gloss but sometimes if the pattern is already at the perfect shape, you don't always want to be adding a high build material to it.
Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant
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Hanaldo
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Group: Forum Members
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+xGenerally we would advise people to avoid paints where possible because of these kinds of issues. And sometimes even 2k paints will come off in the mould, not because of release issues but because the bond to the substrate isn't always that strong. We tend to recommend products like our Pattern Coat Primer and High Gloss but sometimes if the pattern is already at the perfect shape, you don't always want to be adding a high build material to it. Yeh I agree; personally I use Scott Bader's Primecoat and Glosscoat, which I believe will be extremely similar to your coating system. Unfortunate for people that don't have access to these systems. Luckily if you do get a situation where the paint stays in the mould but not due to a release failure, then you can usually still salvage the mould through a combination of compressed air and careful work with a blade - but it still isn't a pleasant task. Every now and then I make a mould off a 2k painted surface, and I'm always very nervous about it. If the paint doesn't look like OEM 2k and is likely a respray, then I don't take the risk and use PVA. Refinishing a mould is far less work than starting from scratch.
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torsten Ker
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Group: Forum Members
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It makes me think that Mr. Gromis used was or PVA or a combination of both as release agent before using the mould, same as I tried
That wax wax then attacked by the polyester gelcoat.
I mentioned that I had the same problem a year ago
and used 2k epoxy primer in a hurry to get the part finished - yes I forgot the epoxy hardener when spraying the epoxy primer by mixing it up with two different canisters of the same thinner :-(
I spotted the mistake straight away when applying the chemical release agent which simply stripped the part of the primer which was due to the missing hardener just being an air drying primer.
Once spotted I waxed 10 coats over it hoping to get away, did the infusion and voilia, the part stuck causing even more troubles
I hope that my gone wrong helps
My Lesson learned - stay away from wax, PVA can be used if a must and surface does not matter
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torsten Ker
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Group: Forum Members
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PS: here is the image what the boat prototype looked like when applying the 2k primer without hardener  thats what it looked like after using the release agent stripping it and sanding it down again  after the mould did not come off clean, I repaired and recoated the lot with 100gsm fibre epoxy and 2K car paint primer and acrylic  and voila after another infusion from a new made mould it worked  Expensive fun but very satisfying once you get there, much more work to do for me from there
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Mr. Gromis
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Group: Forum Members
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+xI assume they are rattle can sprays? You may still have problems as most 2k sprays are still solvent laden. 2k through a professional spray gun is the way to go ideally if you use paints. yes this vid I show that acetone didn't strip the paint thank you for pointing me to 2k paint I will run a test first and post it here
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