EG 160 and air bubbles postcure

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EG 160 and air bubbles postcure

Author	Message
SHaas	S SHaas posted 7 Years Ago HOT Topic Details
S Group: Forum Members Posts: 46, Visits: 383	Hi everybody, I have the same problem with all EG160 moulds I prepared the last months: Taking the part out of the mould shows a perfect finish, but after postcuring in the recommended cycle there are points where it looks like air is trapped. But you could not see it before the curing process... any tips? Regards and a wonderful christmas for everyone!
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Hanaldo	Hanaldo posted 7 Years Ago HOT Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	You need to take more care with trapping air behind the surface coat - the air expands as it heats up, causing the blisters. Take your time to make absolutely sure there are no air bubbles behind the surface coat.
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cumberdale	c cumberdale posted 7 Years Ago HOT Post Details
c Group: Forum Members Posts: 32, Visits: 594	I too have had some problems with bubbles in EG160. Tried to degass but not sure if it‘s that effective as it is very thick in viscosity. Won‘t hurt though. Blowtorches or heatguns may help as well. Slower post curing ramps may also help. For me the backing paste used to be the biggest problem bubble wise, so take your time with that and work difficult areas first.
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Matthieu Libeert	Matthieu Libeert posted 7 Years Ago HOT Post Details
Group: Forum Members Posts: 955, Visits: 3.4K	Like above, try 2 very thin coats, the thinner the coat the easier it will be for the resin to remove trapped air to the surface. It can also help to heat your resin before applying it to reduce the viscosity, resulting in an easier way for the bubbles to find their way to the surface of your coat. Matthieu Libeert Founder MAT2 Composites X Sports website: www.mat2composites.com
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SHaas	S SHaas posted 7 Years Ago HOT Post Details
S Group: Forum Members Posts: 46, Visits: 383	Thanks for all your support! But I have an additional question, perhaps someone had this problem too: I made a vacuum infusion with my part. Because I had to flat the surface with 1200 grit the part didn’t look well. So I decided to use S120 Board sealer on the mould to make it fully gloss followed by 7 applications of easylease. That worked well. The next part I made was Prepreg, which also worked well. But when the part released from the mold nearly all of the S120 came off and crystallized on the parts surface. I could scrap it off, but the surface was again not that well. Has anyone experienced the same problem with S120 on Eg160? Should I have done an additional post cure after using the board sealer?
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Matthieu Libeert	Matthieu Libeert posted 7 Years Ago HOT Post Details
Group: Forum Members Posts: 955, Visits: 3.4K	+x SHaas - 12/27/2018 5:13:47 PM Thanks for all your support! But I have an additional question, perhaps someone had this problem too:I made a vacuum infusion with my part. Because I had to flat the surface with 1200 grit the part didn’t look well. So I decided to use S120 Board sealer on the mould to make it fully gloss followed by 7 applications of easylease. That worked well. The next part I made was Prepreg, which also worked well. But when the part released from the mold nearly all of the S120 came off and crystallized on the parts surface. I could scrap it off, but the surface was again not that well. Has anyone experienced the same problem with S120 on Eg160? Should I have done an additional post cure after using the board sealer? every layer you add later on, will need a postcure so that might have been the problem... to be honest not sure either if s120 is a good way to seal a mould you want to use for multiple pulls, EC staff quote me wrong if I am. The board sealer can withstand high temperatures but I think it's purpose is more to finish the plug, then do the tooling prepreg till 70°C and remove, that way it isn't exposed to many cycles you would have to make prepreg parts out of your moulds. second thing is that if I read it well the mould was sanded till 1200 grit, then "clearcoated" with the S120? If you paint/apply new resin on something you should have a lower grit sanded part, say 600 grit max so the next layers of coating still have a mechanical bond in the scratches of your piece. Also make sure to remove any grease/release/dirt before applying a new coat... you might have had some problems with release still being stuck on your mould before applying the new coat of s120 as well Matthieu Libeert Founder MAT2 Composites X Sports website: www.mat2composites.com
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SHaas	S SHaas posted 7 Years Ago HOT Post Details
S Group: Forum Members Posts: 46, Visits: 383	Thanks for your thoughts. I do not think that the sealer is not usable for multiple pulls. In the tooling prepreg guide is written that you can sand the prepreg mould if you have minor imperfections and restore the gloss with the sealer - which makes no sense if you couldn’t use it multiple times. I am also not sure if it is a good idea to sand the mould with much less than 1200grit because the sealer is not able to close deep scratches. Otherwise this could be the best bet why the sealer came down on the part! For my part it is not that problem because I wanted to make a prepreg plug out of the EG160 mould to produce a tooling prepreg mould. I already cleaned the surface and try to make the „new“ mould this weekend. But it would be nice to understand what was going wrong. Perhaps EC staff lets us know their opinion.
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