Hazy GC50

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Hazy GC50

Hazy GC50

Author	Message
wochi	wochi posted 9 Years Ago HOT Topic Details
Group: Forum Members Posts: 31, Visits: 188	Hi all, i finished my first part today using GC50 gel coat. Poblem is that the part got hazy and on an yellowish side. What could be the problem? I sprayed the mould with gel coat spraying gun, let it cure for about 4 hours (25º over here) and then epoxy infused. Into the oven, cured at 50º for 8h. The primarly objective was to fill the pinholes that i allways get no matter how perfect is the insfusion, and that resulted very well! But when i look at the part compared with other with no gel coat is very noticable the difference. The yellow tone i can understand as beeing a polyester gel coat. But the haze is a big problem. Any ideas for the cause of this? Thank you!
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Warren (Staff)	Warren (Staff) posted 9 Years Ago HOT Post Details
Group: Administrators Posts: 2.5K, Visits: 7.9K	How thick was the gelcoat? Also was it humid when you sprayed or let it cure? Both excessive thickness an moisture can cause a haze Warren Penalver Easy Composites / Carbon Mods - Technical Support Assistant
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wochi	wochi posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 31, Visits: 188	Hi Warren, thanks for your reply. I really don´t know how thick it was. First time using it. But it can´t be that thick as in corners you don´t see a huge layer of gelcoat. Also no drips in the mould when i sprayed. Moisture is not the problem as the lines have filters and i use same line to lacquer my parts with no problem. If it´s the thickness how can i know if i´m applying the correct amount of gel coat?
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wochi	wochi posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 31, Visits: 188	Did another part today, with half the gelcoat. It was so thin it opened some "holes in the mould" but as it was for testing to se if it was a thickness problem I proceed anyway. Still the same problem. Hazy when i look from certain angles. Any solution to this? I ordered 5kg of gc50 and seems that i won´t use it because it´s not acceptable to have parts like this!
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Hanaldo	Hanaldo posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	I'm confident it will be moisture related. You can't necessarily rule out moisture being a problem because you have another type of coating that works fine; different chemicals react differently. I find polyester based coatings are especially sensitive to moisture. Hazy coatings are generally always a sign of humidity being too high for spraying, what is the humidity at the moment where you are? Also don't rule out moisture in the lines, I've gone through 3 different brands of filters before I found one that worked, and that's with a water trap in the line. Gotta empty the water trap every time before spraying, compressed air results in a fair bit of condensation. Otherwise, I've seen haziness caused by a couple of other things too. Using a syringe with a rubber plunger to measure out your catalyst is a big one, the MEKP attacks the rubber and contaminates your coating. Post some pictures if you can, always makes playing e-Doctor a bit easier!
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wochi	wochi posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 31, Visits: 188	First of all thank you for your help! Moisture it´s very unlikely to be the problem. It´s plain Summer Here (28º inside, 55% Humidity) and i have one filter just next to the compressor and another one close to the exit. I spray 2part lacquer with no problem and that usually is impossible with moisture in the lines. I measure the catalyst with the Easycomposites dispenser, no rubber there. It´s really hard to catch the problem in a photo. this is the best i can get you can see it in the top left corner altough in person is visible everywhere
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wochi	wochi posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 31, Visits: 188	Well, the new order arrived today. And there is a big difference in color inside the container. The one I had is Orange, and the one that arrived is purple! Any reason for this? Maybe the one i had was too old or other formula?
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Warren (Staff)	Warren (Staff) posted 9 Years Ago HOT Post Details
Group: Administrators Posts: 2.5K, Visits: 7.9K	Very strange. Perhaps it had started to dry out? We sell a large amount of GC50 each month so the stock is always fresh and doesn't spend long on the shelf. A photo next to each other would be a useful comparison. Warren Penalver Easy Composites / Carbon Mods - Technical Support Assistant
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wochi	wochi posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 31, Visits: 188	upside down but you get the point. Can this be the problem? GC50 beeing too old? How can i see the production date? Edited 9 Years Ago by wochi
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wochi	wochi posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 31, Visits: 188	did another part with the new GC50 and the problem is still there! It´s perfectly noticable from certain angles the "milky" coat. Don´t know what else to do. Any other product that can be sprayed and used as a gelcoat for epoxy infused parts? I really liked the solution as there are no pinholes so the part doesn´t require too much work after coming out of the mould
	Reply Like 3