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Hi to all. It's my first mould using UniMould system. I follow exactly the tutorials and indications for making the mould. For the first step, i have bougth locally an MEKP catalyst ( i have attached the image ). I have applied a thin layer of gelcoat, and 4 hours later, another layer. After that, i have wait to the next day to let it cure, but the surprise was, that the part was totally ruined when i arrived next morning ( i have attached another image ). At that time, it had been drying for about 15h. The gelcoat has reacted with my part ( a motorcycle fuel tank ), producing great wrinkes all around the part. The tank was just finished, laquered and polished with PPG clear coat, and it has been drying for a week before I apply the gelcoat. The room temperature was about 17º in the day, and about 13º overnight. I have made a test yesterday, using 3 small mixes, one in 2%, another in 5% and a extreme one at 10%. The 2% mix, seems to never cure, it has been applied for about 20h right now, and keeps almost fresh. 5% looks nice, it's tacky in the surface and cured in the inside part, and the 10% mix its fully cured. I think the problem has been that the mixture at 2%, has react because it has been applied over the clear coat too much time without cure ( i look at it 6h after the application and it has no wrinkles at all ), producing the wrinkles at the end. The question is, it's safe to work at 5% ? Do you think that the problem it's another one ? Thanks in advance, and sorry about my english.
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Group: Forum Members
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According to my old books from my time building glass-fibre/polyester boat hulls, the actual content of MEKP itself in the "catalysts" can vary from 40% and up to 80% Since the MEKP is just a catalyst, the percentage of catalyst to resin is not very critical, but a combination of only half the expected "actual" percentage of MEKP catalyst AND temperatures that are really a bit too low, and the problem will show its ugly alligatored face ... 
"Sapere Aude"... Dare to KNOW! The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind... 103% of all people do not understand statistics... Do not adjust our mind, theres a fault in reality :-)
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