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JDUB
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Small teardrop shaped plug made of glass and West epoxy. Lots of polyester filler and car spray filler primer to get a good shape and surface. We put on quite a bit of Easy-lease as per instructions, then wax as well. All polished up. Mould made using polyester and glass starting with gel coat and surface tissue. Did not release at all. Took all the paint and filler off the plug Is this to be expected? What should we have done? Small private user. Can't afford complicated systems.
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Hanaldo
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Did you use a single pack primer or a 2k? If it was single pack then it certainly wouldn't work at all. Even if it was 2k, one can often run into problems if you didn't leave it for a few weeks to cure properly or bake it at 60C for a few hours. Lots of solvents in automotive primers and paints, so even though they are hard to touch they aren't actually fully cured for quite awhile. And then the heat the gelcoat generates when curing can cause the primer to soften and bond.
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JDUB
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Group: Forum Members
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+xDid you use a single pack primer or a 2k? If it was single pack then it certainly wouldn't work at all. Even if it was 2k, one can often run into problems if you didn't leave it for a few weeks to cure properly or bake it at 60C for a few hours. Lots of solvents in automotive primers and paints, so even though they are hard to touch they aren't actually fully cured for quite awhile. And then the heat the gelcoat generates when curing can cause the primer to soften and bond. Thanks. Single pack spray. Sounds like it will be difficult to make the things I plan with a reasonable timescale. I had hoped the wax would form enough of a layer to isolate. Seems not.
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Hanaldo
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Wax doesn't form a barrier, you need to use PVA.
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JDUB
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+xWax doesn't form a barrier, you need to use PVA. Reluctant to use it as it does not seem to maintain a good finish. May have to if I can't afford the complicated systems.
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Hanaldo
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Yeh you haven't got much choice, there's no real short cuts. If you can't use surface coats that resist the solvents in the gelcoat and heat from the curing of the mould, then you need something that forms a barrier between the two - that's PVA, or wrapping the object in release film or release tape. Those two options will prove much more difficult than PVA.
That said, PVA can be sprayed in such a way that it can give you a decent surface finish - certainly as good as a primer finish anyway. You will still need to do a bit of denibbing and polishing of your mould to get a truly Class A finish, but you would have needed to do the same off the primer surface as well.
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f1rob
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+xSmall teardrop shaped plug made of glass and West epoxy. Lots of polyester filler and car spray filler primer to get a good shape and surface. We put on quite a bit of Easy-lease as per instructions, then wax as well. All polished up. Mould made using polyester and glass starting with gel coat and surface tissue. Did not release at all. Took all the paint and filler off the plug Is this to be expected? What should we have done? Small private user. Can't afford complicated systems. All the semi perms be it from frekote,chemlease,marbocote whoever only work on a none pours surface Bet your sealer is being soaked through your paint into your filler If you have a rough pattern that's pours all manufactures do mould sealer that will give you a none pourus smooth ( an shiny if applied correctly) surface for your release If you go for your painted Finnish an you have doubts all the manufactures do what are essentially semi perm mould was combos Frekotes version is called free as an is a mixture of 700 release an a wax Poured on a cloth a wiped on for a cloudy Finnish then buffed off when dry 6 lots of that an nothing will stick an your pattern will still be shiny as a shiny thing
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JDUB
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Group: Forum Members
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+xYeh you haven't got much choice, there's no real short cuts. If you can't use surface coats that resist the solvents in the gelcoat and heat from the curing of the mould, then you need something that forms a barrier between the two - that's PVA, or wrapping the object in release film or release tape. Those two options will prove much more difficult than PVA. That said, PVA can be sprayed in such a way that it can give you a decent surface finish - certainly as good as a primer finish anyway. You will still need to do a bit of denibbing and polishing of your mould to get a truly Class A finish, but you would have needed to do the same off the primer surface as well. Release film sounds interesting. Searched but not found a product. PTFE perhaps?
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Hanaldo
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Group: Forum Members
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+x+xYeh you haven't got much choice, there's no real short cuts. If you can't use surface coats that resist the solvents in the gelcoat and heat from the curing of the mould, then you need something that forms a barrier between the two - that's PVA, or wrapping the object in release film or release tape. Those two options will prove much more difficult than PVA. That said, PVA can be sprayed in such a way that it can give you a decent surface finish - certainly as good as a primer finish anyway. You will still need to do a bit of denibbing and polishing of your mould to get a truly Class A finish, but you would have needed to do the same off the primer surface as well. Release film sounds interesting. Searched but not found a product. PTFE perhaps? Might be a bit of a misleading title in this context. Release film is intended to go on the reverse side of parts, to prevent vacuum bagging consumables from sticking to the part. A non-perforated release film does leave a high gloss finish, but it is virtually impossible to use as a surface unless you can stretch it quite rightly, as it does wrinkle and crease etc. It can be done if your part is very simple, but if there are any compound curves then forget about it.
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scottracing
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You can use materials like tygaflor which is a sticky backed ptfe release film. Ive used it several times on mdf moulds.
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