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Cutting a new mold for a foil
Posted: Sun Jul 15, 2018 9:13 pm
by SaulOhio
https://www.facebook.com/saulius.muliol ... 679634741/
I'm using HDPE instead of expanded PVC this time. No more glazing putty and painting the mold. I just have to sand it, and I may not even need a release agent.
Re: Cutting a new mold for a foil
Posted: Sun Jul 15, 2018 9:34 pm
by TomW
What machine are you using?
Re: Cutting a new mold for a foil
Posted: Sun Jul 15, 2018 10:48 pm
by SaulOhio
TomW wrote: ↑Sun Jul 15, 2018 9:34 pm
What machine are you using?
Inventables X-Carve.
https://www.inventables.com/
Re: Cutting a new mold for a foil
Posted: Mon Jul 16, 2018 2:30 am
by NorCalNomad
Rad! But still use a release agent, you aren't going to be worse off for it, and I've definitely seen epoxy stick to HDPE.
Re: Cutting a new mold for a foil
Posted: Mon Jul 16, 2018 2:42 pm
by TomW
are happy with it ?
Re: Cutting a new mold for a foil
Posted: Mon Jul 16, 2018 2:53 pm
by SaulOhio
Edited
Re: Cutting a new mold for a foil
Posted: Mon Jul 16, 2018 2:54 pm
by SaulOhio
TomW wrote: ↑Mon Jul 16, 2018 2:42 pm
are happy with it ?
Some little fuzzies stuck to the mold, but otherwise it came out perfect. It just took most of the day. I'm wondering when I'm going to have the time to carve the other side of the mold.
And then the stabilizers. And the mast.
NorCalNomad wrote: ↑Mon Jul 16, 2018 2:30 am
Rad! But still use a release agent, you aren't going to be worse off for it, and I've definitely seen epoxy stick to HDPE.
What kind of release agent would you recommend for West Systems epoxy on HDPE?
Re: Cutting a new mold for a foil
Posted: Mon Jul 16, 2018 2:56 pm
by TomW
NorCal is right. Epoxy can stick to HDPE.
Usually you have to "flame it" to et it to stick, but it might stick anyway.
Re: Cutting a new mold for a foil
Posted: Mon Jul 16, 2018 6:38 pm
by rynhardt
A good mould release schedule on a gel coat mould would be 6 layers of carnuba wax (wax on/wax off) and then a layer of pva release agent.
On HDPA you may need less layers of wax.
The pva forms a thin sacrificial skin which dissolves with water when you remove the cured piece - highly recommended if you want to re-use your mould.
You can see me apply this at about 0:27 in the video below.
Re: Cutting a new mold for a foil
Posted: Mon Jul 16, 2018 7:17 pm
by SaulOhio
rynhardt wrote: ↑Mon Jul 16, 2018 6:38 pm
A good mould release schedule on a gel coat mould would be 6 layers of carnuba wax (wax on/wax off) and then a layer of pva release agent.
On HDPA you may need less layers of wax.
The pva forms a thin sacrificial skin which dissolves with water when you remove the cured piece - highly recommended if you want to re-use your mould.
You can see me apply this at about 0:27 in the video below.
I have used PVA. The problem with PVA is its hard to fix mistakes. Any runny spots, or a bubble, or a piece of dust that lands on it is there for good. I like waxes because I can buff out any mistakes.