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Old 16th June 2020, 08:18
Mitchelkitman Mitchelkitman is offline
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Was there wax on the mould before the PVA was added? I've tried to use PVA in the past, and found it beeded, also when I tried to get my object out that it was stuck fast in the mould! I gave up using PVA, and just rely on wax. Last year a made a mould, and a week later waxed it many times (no PVA) and a part got stuck permanently in the mould. I then read on the 'net that GRP that isn't fully cured can still cross-link with more GRP even with a release agent separating them - that seems plausible, because I then made a new mould and let it cure for 2 weeks, did a couple of wax coats, and subsequently laid up a part with popped out with hardly any effort. I was making a very small plug for a part a few days ago and couldn't get a great finish on it, and decided I'd put some PVA on it to achieve the smooth finish..... As I was putting it on by brush I couldn't get it smooth anyway, so thinned it with water, which meant i achieved a smooth finish. but interestingly when it dried it appeared a lot thinner! We'll see what happens. BTW It was the same PVA as I'd used before, but no wax on the plug, and the PVA didn't beed.
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