Well, since my previous molds are all epoxy based, this new gel coat tooling / ester based mold… took a part out and it was stuck!. i had 10 layers of wax let it sit. clear gel coat brushed, etc etc. took it out not to long ago but i had to pull hard. and parts of the MOLD were stuck on the part! ahhh!
re-molding the part, and hopefully i will first spray 7-10 layers of PVA THEN gel coating.
im using partial wax inside of the mold. is there a better wax?
“Green” molds should always be waxed AND pva’d for the first few parts until the surface of the mold is fully sealed. Even with semi-permanent release, I occasionally get sticking with new molds.
then heres a good question, what seals a mold, meaning if wax + pva get placed on a mold… whats the actual action that it gets sealed?
Ive never done Partial wax + PVA at the same time has anyone else?
partall actually builds up really bad, i kinda hate it. love pva as i learned how to spray it really well…
has anyone used TR 104 HIGH-TEMP Mold Release Wax?
I ONLY use the TR 104.
I never use pva or anything like that.
I do the exact same as you ^^^^^ Never even seen PVA before lol
and it wont eat away through the wax?..
what wont eat thru the wax?
The only time Ive ever stuck a part in a mold and ruined the mold was in the beginning of my part making experience…
It was really cold out and I tried to help kick the stupid gecoat off a bit faster by holding the mold up near the propane heater…bad move.
It got hot enough that the gel welded into my mold…destroying it.
Ive never stuck a part again. Ive had to chip out some gelcoat when I have an infusion go wrong and it doesnt get finished. But it comes out with a razorblade edge easily enough.
well im more worried about it eating through the wax and getting to the part and messing up the part. When it says high temp, does this just mean it wont melt away from the high heat. and whats the# on that?
I have used that same wax but found that automotive eagle 1 nanowax sticks to the mold much better. I have forgetten to pre-wax molds before that have had a few parts pulled from them with no sticking at all.
Lets just say Ive layed…4 layers of 3.5oz chopped strand mat (pretty thick if you ask me for hand layups) and all the resin it took to wet it out and layed it in the sun after I got them layed up to help kick it off and my molds turned out money.
That was last week as a matter of fact.
I use Meguiar’s #8 Mold Wax with no PVA. Works like a charm. Never had a part stick yet and I don’t have to re-wax every time…
I plan on using partall#2 wax 5coats andbuffed, then 10-15 light coats of pva. I won’t trust doing it any other way… wax and Pva each with many coats.
that’s coolon the maguires wax… i just bought some from Racedout. I’ll still use pva over it though.
yea i dont know how that partall wax is…it just smells nasty and i would rather use somethign that doesnt stink…i just use some regular old caranuba wax from autozone and a crapload of pva
If you dont mind quite a bit of extra work, and not that great a surface finish then using pva is fine. Personally though in the 4 years I have been laminating, not had a single problem using just wax alone.
I think the main reason people have problems with wax, is down to buffing too vigourously, so that some areas of the mould are devoid of wax.
Do you mind sharing any tips on how to spray PVA w/out getting orange peel and spider webs??? =) I’ve tried with a gravity feed cup gun and a 2.0 tip at 90psi. I heard somewhere that if you thin the pva down with water it helps, but don’t know the ratio. Thanks in advance!
Cheers,
Jeremy
sure will. i think your 2.0 tip thou is WAYYY toooo big. all i use is a mini hvlp gun from harbor freight. cost is about 50$? its great and ONLY use it for this.
test it on some parts, you dont need that much psi, i get around 45-55. and the air/feed nozzle not set toooo high. maybe 3/4 the way in , clockwise.
you want to light mist it. i give it about 2-3 passes , light ones each time. LET IT DRY , DONT be so close to the PART! you will have runs, pooling etc. spider webs happen when you have a REALLLYYY high heat next to you. dont do this. let the part dry on its own. come back, and do it atleast 3-5 times more. you’ll get a nice glossy finish 
Surely its far easier to just get used to working with wax, rather than wasting time and money using PVA?
I have one mould that is used to make motorcycle fuel tanks, that has proabably provided about 80 mouldings, its never seen anything other than wax, and there hasnt been a single problem with release.
Another advantage of wax, is that after properly waxing initially, and after 4-5 pulls out of a well made mould, that there is no real need to apply wax, other than on an infrequent basis.
Well, I think there are sometimes when using pva is a good idea, that’s why I asked for the tips. I have had good success using only wax on a mold. But my interest is in getting a good release and finish from a plug that is made of several different materials and I want to ensure no reaction with the tooling gel coat. For that PVA is the ticket! Provides a good physical barrier between the plug and the gel! =)
Thanks luisn!
i agree, to all their own ya know? everyone has diff techniques.
no prob.