A question about fumed silica

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A question about fumed silica

Author	Message
kaan79	kaan79 posted 10 Years Ago HOT Topic Details
Group: Forum Members Posts: 3, Visits: 135	Hello everybody, I have been in trouble with liquid wax release agent(Raku-Tool AC-9103)I was going to make epoxy mould.However mould has been sticking to plug.The technical guy has told me that the fumed silica should be scratch to release agent.I could not understand really why.I know most of people use silica with gelcoat but I have not seen any complain about it.By the way I have painted the plugs with PPG 2k acrylic primer and top coat. I am just wondering that If I use fumed silica with epoxy tooling gelcoat.Does it scratch or damage the liquid wax release agent on the plug? Thanks.
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Hanaldo	Hanaldo posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	I'm not sure if you've misunderstood what he meant or if he is talking rubbish... Silica isn't going to 'scratch' anything, that's rubbish. What might happen is if it hasn't been mixed properly, you get dry 'pockets' of silica in the surface of the plug, which then fall away and leave porosity. Which could cause a stick. Silica needs to be mixed properly, and it's a bit of a bitch to mix.
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kaan79	kaan79 posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 3, Visits: 135	Yes you are right Hanaldo.It was hard to mix silica and gelcoat.But I am pretty sure that I mixed them up properly.I am sure because The flanges are ok where I have covered the flanges with Teflon PTFE film.The mould released well from flanges.He exactly said to me silica should be scratch to release agent as micro scratches .So the release agent did not work as he thought. Attachments Mold-2.jpg (368 views, 332.00 KB)
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Hanaldo	Hanaldo posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	I can't see that makes any sense, physically. If silica scratched release agent like that, then the bristles of a brush would be 10 times worse. I don't think the silica has anything to do with it.
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kaan79	kaan79 posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 3, Visits: 135	Thanks Hanaldo for information.I am agree with you.What release agent do you suggest me for mould making?I am making epoxy wet lay-up mould.And I need to pre-curing the moulds at 60 C degrees for 8 hours on the plug.
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