TPE release from mold

BigBurrito · Post by **BigBurrito** » Sat Mar 09, 2019 4:02 pm

Can anybody give me a suggestion of a good release agent for molding TPE in a Plaster of Paris mold

Rick9191 · Post by **Rick9191** » Sat Mar 09, 2019 5:52 pm

BigBurrito wrote:Can anybody give me a suggestion of a good release agent for molding TPE in a Plaster of Paris mold

LOL Great minds think alike. I'm awaiting my new "labia" façade mold to dry and then onto pouring. From what I've read. Prep the mold with high temp engine paint which will seal the plaster and add a level of heat protection for it. I was going to add a mineral oil coating inside the mold and pour. TPE's around 400F which the plaster should hold if there's no air bubbles in it and it's dry. Mold should be preheated to 150F. Anything above and you'll get spalding (mold face crumbles) but if you pour cold it might set the tpe to fast in mold contact areas and the insides could warp or so I've gleamed from reading misc posts and molten plastic molding techniques on special effect sites.
Be nice to hear from anyone who's done it and the results, prep etc.... Obviously there's a few of us out here working on mods or replacement parts.

david 68 · Post by **david 68** » Sat Mar 09, 2019 7:10 pm

i been searching in learning on how to create in doll making as a hobby,its possible to do so .just need a creative mind .i was thinking the same on how to release tpe or silicone parts from its mold with out any tearing ,sticking and so on.

i was wondering if a hard plastic molds are being used to pore molten tpe?

Fantastic Plastic · Post by **Fantastic Plastic** » Sat Mar 09, 2019 7:56 pm

It’s usually a fiberglass mold with a resin sealer inside.
A release agent may be as simple as a mixture of talcum in an alcohol carrier sprayed on the inside of the mold with just a cap full of mineral oil to help hold it in place.
Just a thought.

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Or this stuff?

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Rick9191 · Post by **Rick9191** » Sat Mar 09, 2019 8:27 pm

Fantastic Plastic wrote:It’s usually a fiberglass mold with a resin sealer inside.
A release agent may be as simple as a mixture of talcum in an alcohol carrier sprayed on the inside of the mold with just a cap full of mineral oil to help hold it in place.
Just a thought.
1E5EF608-9D1A-404D-8D42-52EF727D7CAF.jpeg

9C20D113-B11F-476C-8F60-5562F6D67312.jpeg
Or this stuff?
2EB1AE72-06DC-42CE-87DA-9035496AF424.jpeg

Thank you FP. I've heard wd40 and few other suggestions but was only guessing on the mineral oil figuring it was already a component of tpe and couldn't hurt it. I like the talc powder idea since I also use that for making plaster molds to eliminate air bubbles. May do the same with tpe. Guess I'll do some trial and no doubt lots of errors. LOL

Fantastic Plastic · Post by **Fantastic Plastic** » Sat Mar 09, 2019 8:48 pm

You’ve got the right mindset Rick! Your going to make mistakes, actually you want to count on it!
You can write down exactly what TO do, and it would just be a pamphlet.
Write down what NOT to do? You’ll have a set of encyclopedias!

Rick9191 · Post by **Rick9191** » Sun Mar 10, 2019 8:47 am

Fantastic Plastic wrote:You’ve got the right mindset Rick! Your going to make mistakes, actually you want to count on it!
You can write down exactly what TO do, and it would just be a pamphlet.
Write down what NOT to do? You’ll have a set of encyclopedias!

Thanks. It's working with a hot media that's throwing me some curves. I've made molds out of most available products. I've poured clay(slip), cement, silicone, plaster, latex. But all of those are cold pour products.
I've heated plaster molds up for various reasons and if they're wet or have an air pocket. Ya can end up with a pretty impressive "boom" and shrapnel. I've cracked molds just pouring plaster in plaster since plaster gets pretty hot as it cures.
I may say screw it and learn Fglassing just for the safety aspects.
So far all of my projects are small. Adding a more detailed labia façade to a doll. New boobies (small cup) on a "small breasted" doll which is actually flatter than a board. Should have been a "no breast" doll. That's my largest mold at around 3" dia and 2.5" h. But even small I don't want a 300 to 400F material getting loose.
The titties I may attempt a direct pour right onto her body to see if it's possible and how well the bond is compared to all the "glues" available that don't seem to "glue" so well. Indigo's Cold Weld would be a life/time saver but I guess there's issues with it or I'd be buying by the gallon. LOL
My mistakes encyclopedia will be more volumes than Brittania's.

Fantastic Plastic · Post by **Fantastic Plastic** » Sun Mar 10, 2019 11:04 am

Yes, Besides equipment and materials, 99% of what effects the final outcome is the time and money put into the mold.

BigBurrito · Post by **BigBurrito** » Sun Mar 10, 2019 2:56 pm

Thanks guys for the ideas, i have a face mask neg mold and a face interior insert that drops in the face mold with alignment rods quickly after the TPE is poured, so the eye lids and mouth thickness is consistent, as the lip interior. Thinking that i brush on liquid latex on the mold insert to seal the plaster, then using mineral oil/ talcum pdr for a release formula

BigBurrito · Post by **BigBurrito** » Sun Mar 10, 2019 3:01 pm

At least with TPE, it's easy to correct fails, can be remelted, rinse and repeat, unlike plat cure silicon

Rick9191 · Post by **Rick9191** » Sun Mar 10, 2019 8:25 pm

BigBurrito wrote:Thanks guys for the ideas, i have a face mask neg mold and a face interior insert that drops in the face mold with alignment rods quickly after the TPE is poured, so the eye lids and mouth thickness is consistent, as the lip interior. Thinking that i brush on liquid latex on the mold insert to seal the plaster, then using mineral oil/ talcum pdr for a release formula

BB Ya just gave me an interesting idea for the labia facia I'm going for. So you have the neg. You'll fill that then press the positive in to force or compress the tpe into details and cavities? What am I missing besides having to be damn careful about molten tpe being forced out along the mold edges? LOL

BigBurrito · Post by **BigBurrito** » Mon Mar 11, 2019 2:44 pm

I will setup the master mold on a cookie sheet to catch the spill over TPE, and also, like i read in this tread, to pre heat both molds to approx 150F to make the forming go smooth. I fractured the face mold in 3 parts (like the connecting rod big end on a 4.6/5.4 Ford) fracture fit, and hold together with a ratchet strap, pieces fit perfectly

Rick9191 · Post by **Rick9191** » Mon Mar 11, 2019 5:27 pm

OMG I think I dated his sister. LOL
Looks like it may work. Have a way to weigh down the positive until you get the thickness you want and a way to lock it into place during curing. I'm thinking like an apple press type thing with woodworkers clamps. I don't think you'll just be able to press it in and let go. Gravity will be working against you. But I'll be damned if that doesn't look like a good way to get an easy fill and a way to force the material where you want it and control the thickness.
I may rethink how I pour the labia I'm working on. A pressure fit would definitely guarantee details, nooks and crannies filled. Another benefit is it may also press out more if not all air bubbles. That's why dolls are pressure injected molds. Get to the toes and get rid of air.

BigBurrito · Post by **BigBurrito** » Tue Mar 12, 2019 7:28 pm

I have 1/8th inch rods that index trough the eyes and both the face and inside mold to index in alignment. The eye's and the mouth bridge hold the thickness sense both molds make contact in those areas, voiding those areas of TPE, so little trimming needed in the post mold process. Hope that explains what you are after. BTW, i have a pressure cooker that i may convert to a TPE pressure injector, by having a tap and air fitting to force controlled air pressure to the chamber, and a pickup tube going from the bottom to a fitting on top that connects to the mold, just an idea anyway, and having experience in metal fab like building choppers in my past, and another one this spring

Rick9191 · Post by **Rick9191** » Tue Mar 12, 2019 8:28 pm

BigBurrito wrote:I have 1/8th inch rods that index trough the eyes and both the face and inside mold to index in alignment. The eye's and the mouth bridge hold the thickness sense both molds make contact in those areas, voiding those areas of TPE, so little trimming needed in the post mold process. Hope that explains what you are after. BTW, i have a pressure cooker that i may convert to a TPE pressure injector, by having a tap and air fitting to force controlled air pressure to the chamber, and a pickup tube going from the bottom to a fitting on top that connects to the mold, just an idea anyway, and having experience in metal fab like building choppers in my past, and another one this spring

Okay I can picture what you mean and that explains why the eyes already have holes in 'em. LOL Pressure cooker set up sounds like an interesting idea. I'd say worth it for lots of molding but I think the press fitted halves might work out as an easier set up. Especially using the eyes and mouth as depth gauges and mold seats. Fill, press together, avoid hot tpe shooting out the sides and ya done.

And kool doin' the chopper thing. I'm not much of a fabricator and no longer ride do to bad knees. Looked at those cam am things and trikes but none seem to grab my attention. Bitch gettin' old. LOL
Good luck on the project and keep us posted