I got some weird problems I never had before in all my vinylester moulds I made.
I'm now using a high temp 145°C vinylester mould system  and to be sure I get no release problems on the parts  carbon fibre winglets I used PVA

So I waxed mould 7 times with high temp wax and than used pva this all went well .
After the layup the release was verry good little to good even it almost fel off but  the problem is the high gloss clearcoated carbon winglets are full  little pinoles and the mould surface also .

after demoulding I stil could peal off the pva film from the  gelcoat side verry good .

I'm using  partal coverall pva purple one because this works with the  tr104 high temp wax

I'm not sure what the problem is... it sounds like you made a mould off pinholed parts and now have pinholes in your mould? But that's not something you would need to ask about, so I feel I've misunderstood. Can you rephrase or maybe post some pictures?

hehe , no the plug part was high gloss clearcoated carbon fibre  and the plug came out full "pinholes"
I only made mould of the small side where the threads are  this part was as glossy as the rest
Its almost as if it was burned



Mould surface looks the same

Oh, that's just a reaction between the gelcoat and the paint on the part. Quite normal when moulding off polyurethanes. They soften slightly and get a little bit attacked by the styrene. Not enough to cause an issue, but enough to haze both surfaces a little. 

Mould will just need a cut and polish.

Just remembered you were using PVA, which makes it a bit less normal. How much PVA did you apply and how did you apply it?

+x

 

Hanaldo - 3/28/2021 12:43:40 PM

Just remembered you were using PVA, which makes it a bit less normal. How much PVA did you apply and how did you apply it?

I used 7 layers high temp wax and brushed on 1 layer pva
I could easy peel off the film of pva  from the mould side  so it wasn't so thin actually
I never had these problems before with normal vinylester mould making  gelcoats
even when I used easylease on a painted part it didn't leave any changes than little easylease build that came of with hot water and soap

the part isn't a little attacked its like 800Grid sanding paper rough look right of the number 02 on the part right from the thread sticking out

Yes, I can see the texture. It looks very much like what I have experienced when moulding directly off some polyurethanes without the use of PVA. PVA should have prevented it, though I generally spray 5-6 layers of it so that it, so I dont know if brushing on one layer would be enough if it didn't form a closed surface. My gut feeling is that it would still protect the surface, and so this isn't that same reaction problem.

Which makes me feel like it is potentially a heat issue. Perhaps the exotherm of the gelcoat curing got too hot for the paint to handle and it bubbled. But really just guessing now, there's so many possibilities with the various chemicals in play that it is quite difficult to know for sure.

+x

 

Hanaldo - 3/29/2021 3:11:29 AM

Yes, I can see the texture. It looks very much like what I have experienced when moulding directly off some polyurethanes without the use of PVA. PVA should have prevented it, though I generally spray 5-6 layers of it so that it, so I dont know if brushing on one layer would be enough if it didn't form a closed surface. My gut feeling is that it would still protect the surface, and so this isn't that same reaction problem.

Which makes me feel like it is potentially a heat issue. Perhaps the exotherm of the gelcoat curing got too hot for the paint to handle and it bubbled. But really just guessing now, there's so many possibilities with the various chemicals in play that it is quite difficult to know for sure.

The weird thing is when I use easylease only it wont change the texture it only makes the clearcoat "swell" get bigger and after time when demoulded the clearcoat shrinks slowly.
So I also was thinking heat  but stil the reaction with the pva from heat  I find strange