Release Agent for WED Clay

[Scream 31]

I'm pretty new to sculpting and mask making (about 5 months,) and everything has been going great - except for the molding process. For the life of me, I cannot figure out a consistent way to release my WED sculpture from the mold. This has led to at least 6 or 7 destroyed sculptures. I've browsed around the internet, including this forum, and I see suggestions for mold releases in general, but nothing that is necessarily made for WED clay. The products I'm using are WED Clay, USG No.1 Plaster, and I typically use Pledge as a sealant. Any straightforward advice would be an immense help. Thank you!

 

[lmgill]

A couple of things to use.
1. paint your sculpture. I use Krylon spraypaint. No use in using clear, just because it's clear, and you can't see it, doesn't make it better. In fact, since you can't see it, it is hard to see where you have missed an area, or where you painted it heavily. Do not use a gloss paint. The "wetting" agents in the paint will make it more prone to fisheye. Use a semi-gloss / satin paint ( white, black just as long as it isn't gloss) If you really want to be cruel to yourself, use silver. This will show every finger print, tool mark and bump.

Side note: You can paint clay with gloss paint, you just should put down a primer first, this will help reduce the chance of the paint fisheying. On many occasions, I have needed to have a very smooth surface on a clay sculpt (A 1/3rd scale Ford Focus car body, as one example) In this case, we have let the WED clay get "leathery" then painted it with Krylon primer, then a couple of coats of Krylon gloss paint. Letting it dry well between coats. Then, with a little talc and a soft cloth, we buffed the sculpture gently by hand, to smooth the sculpture and remove any tool scratched before molding.

2. Mix talc (Baby powder) with alcohol (denatured) and put it in a spray bottle and making sure it's shaken up well, spray your sculpture. Do not do this around any open flame or heat source!! Let the alcohol evaporate, and it will leave an even coating of talc. I have had very good luck with this when using gypsum molds.

Also, with any new thing....test!
I see this all the time. Someone is unfamiliar of how a technique or material will behave, and they try it the first time on a finished or nearly finished thing. Make a little test sculpt, something simple, but has some of the surface features, and test the process before going at it on a complete, finished sculpture.

Good luck

 

[BiffSuperman]

Are you trying to release your sculpture 'intact' from the mold without destroying the clay sculpture? From your post that is what it sounds like.

No matter what your clay sculpture will be toast. All you need to care about is that shiny new mold.

 

[udog]

As said above, trying to get a clay sculpted model perfect out a mold might be imposible. If that´s the question.
But as you are talking about release, just one comment:
If it´s sticking to the plaster most probably what is sticking is the sealer. If you seal a clay sculpt, you should release the sealant. Sealers are not release agents.
There are soap release agents thought for releasing plaster that will work, your plaster supplier or any FX store should carry it.
I personally never seal clay if I´m molding it with plaster. Nor normal water based clay nor oil/wax based clay. No need to seal it in first instance (unless there is a visual reason for doing this), it releases by it´s own from plaster.
I know many use a sealer for clay. But many don´t too.
I would recommend picking some WED small chunks and pouring some plaster on them. One with no release, one with sealer, one with sealer and a soap release (you coluld use a dish hand washing soap to try, like Fairy or similar, you can thin it with a little water) and one just with the soap release and see what´s going on. Most probably the only one that should give problems is the one with the pledge and no release as I see it.
One reason I do apply a soap release on water based clay is to aid in the mold cleaning part.

 

[Scream 31]

I appreciate the advice, everyone!

For clarification: I'm not looking to preserve the sculpture, upon molding. I have a problem with the sculpture sticking like all hell to the plaster mold, and having a very difficult time separating the plaster mold from the sculpture underneath. This has often led to me accidentally breaking the mold while trying to separate the two. I wasn't sure how to make the separation of the mold and sculpture easier on me, because it's usually an hour-long struggle, if not longer lol.

 

[udog]

I'm not looking to preserve the sculpture, upon molding. I have a problem with the sculpture sticking like all hell to the plaster mold, and having a very difficult time separating the plaster mold from the sculpture underneath. This has often led to me accidentally breaking the mold while trying to separate the two. I wasn't sure how to make the separation of the mold and sculpture easier on me, because it's usually an hour-long struggle, if not longer lol.

Ok.
Once you have separated the mold´s parts does the clay peel off the plaster fairly easy?
Or does the surface of the clay seem to have sticked to the palster?. Then I´d say 99% it´s the pledge sticking. You must release the pledge with a mold release over it, for example a soap release agent. Actually, I wouldn´t use pledge unless you have a good reason for doing so
But if it´s not that and you are having a hard time prying open the mold here go some considerations:
I assume the clay is soft enough as it´s WED and it´s shouldn´t dry out as plain water based clay can do if not taken care properly.
Is it a two part mold with an opening somewhere?. Are you releasing correctly the seam?
If it is, a way to open the mold without putting that much stress in it would be digging all the clay you can out from any open part (neck in the case of a head). Take out as much as you can. Then fill the mold with water and wait a little. This sometimes aids the opening and it might start separating by itself. Works with water based clay, not sure if it will do with WED as it´s glycerine based. Anyway, digging out as much as you can before prying it open will allways help.
This said without knowing what kind of molds you are talking about (one part, two..,).
In any case, sometimes opening a mold needs tender care and patience. Take in account that when you made it vacuum took place. All air was driven out. To open, air needs to come in again. Slow repetitive motions work better than big efforts sometimes.
Also, if your molds break when opening, could they be too thin?..how thick are they?. Are they reinforced some way?. Burlap for example.

 

[Scream 31]

Ok.
Once you have separated the mold´s parts does the clay peel off the plaster fairly easy?
Or does the surface of the clay seem to have sticked to the palster?. Then I´d say 99% it´s the pledge sticking. You must release the pledge with a mold release over it, for example a soap release agent. Actually, I wouldn´t use pledge unless you have a good reason for doing so
But if it´s not that and you are having a hard time prying open the mold here go some considerations:
I assume the clay is soft enough as it´s WED and it´s shouldn´t dry out as plain water based clay can do if not taken care properly.
Is it a two part mold with an opening somewhere?. Are you releasing correctly the seam?
If it is, a way to open the mold without putting that much stress in it would be digging all the clay you can out from any open part (neck in the case of a head). Take out as much as you can. Then fill the mold with water and wait a little. This sometimes aids the opening and it might start separating by itself. Works with water based clay, not sure if it will do with WED as it´s glycerine based. Anyway, digging out as much as you can before prying it open will allways help.
This said without knowing what kind of molds you are talking about (one part, two..,).
In any case, sometimes opening a mold needs tender care and patience. Take in account that when you made it vacuum took place. All air was driven out. To open, air needs to come in again. Slow repetitive motions work better than big efforts sometimes.
Also, if your molds break when opening, could they be too thin?..how thick are they?. Are they reinforced some way?. Burlap for example.

Yes, the clay peels out very easily once I actually manage to separate the mold from the sculpture. All of the molds I've attempted have been half-molds. Half masks, faces, etc. I run into the biggest issue when I sculpt and mold a half mask on a 3d head armature. When I've tried to sculpt and mold a half mask on a flat board or something of the sort, it's usually a lot easier for me to demold. But for some reason, the head armatures create a suction from hell that really doesn't want me to be able to remove the mold lol. And, because it's a 3d head, it's much more difficult to find points of leverage where I can pull on to try to separate the two. If I manage to do so, though, the clay peels out no problem, aside for light clay residue on the inside of the mold.

I'm still new to all of this, so I'm trying to figure out what I can and can't do. I considered sticking the armature with the sculpture and mold intact into a 5 gallon bucket of water for a bit, but I didn't know if that would cause issues with either the details inside the mold, or if the moisture would stop the plaster from curing all the way. I made the mistake with one of my earlier sculpts of adding water to the outside of the mold while it was curing to smooth it out, and it never fully hardened after that. The breakage usually happens when I make a mold on a 3d armature, because I have to find weird angles to push and pull the mold from. That said, I do sometimes notice that the very outermost edges end up brittle.

I appreciate your insights so far, by the way. They've been extremely helpful.

 

[udog]

Yes, the clay peels out very easily once I actually manage to separate the mold from the sculpture.

Ok, no release issues then I´d say.

I run into the biggest issue when I sculpt and mold a half mask on a 3d head armature.

The breakage usually happens when I make a mold on a 3d armature

All of the molds I've attempted have been half-molds. Half masks, faces, etc

For what I read I assume we are talking about a one part mold.
Could it be you are facing some kind of locking or slight locking there?
How thick is the clay you laid over the 3d armature?.
Sometimes the armature shape could be locking the mold. If the clay you added on top is too thin in certain areas or if the seam or end flange of the mold locks with some part of the armature. Sounds like something similar could be going on.
Yes, fixing something on the armature that aids leverage would help. But take in account the strength employed to open a mold is a big deal though it might not look like so. So it must be a very sturdy fix.
In any case remember slow repetitive movement to get air in will make more that one straight strong pull.

The other thing to take in account is why are your molds breaking. What plaster are you using?. Are your mix and proportions correct?. How thick are the molds?. How do you mix and prepare your plaster?. If not done correctly it can result in more brittle material.
Plaster molds must be at least 2-3 cm thick (better 3 in your case) in a general basis and with no reinforcement.
Stone plaster (like UC30) would be a strong option if you are having problems. Reinforcing your molds with burlap helps too.
Also, you must let the plaster set completely. Sometimes opening too soon can result in cracking. In your case, as it seem to be hard to get it out, let it sit 24h.
If you are having this problem one thing to do is to go for stronger molds.

I considered sticking the armature with the sculpture and mold intact into a 5 gallon bucket of water for a bit, but I didn't know if that would cause issues with either the details inside the mold, or if the moisture would stop the plaster from curing all the way. I made the mistake with one of my earlier sculpts of adding water to the outside of the mold while it was curing to smooth it out, and it never fully hardened after that.

What I said about filling with water would apply on a two part mold. Not sure it would help that much in your case.
Anyway, if a plaster mold is fully hardened (lets´s say 12h-24h) there´s no problem wetting them. This is, if the proportions and mix are correct. When using water based clay the best way of cleaning is with water and a brush or similar (done this hundreds of times). So nothing wrong should happen, unless the plaster is not well done.
One way of knowing your plaster has set and is prepared for demolding or cleaing etc. is when it has cooled down. Plaster heats in the hardening reaction. When it cools down it has set, the main reaction is over. This doesn´t mean it has dried totally (this can take weeks). But you can then work with it.
In the case you mention, trying to smooth out the surface with water (something that can be done), I´d say that the plaster wasn´t in the propper stage for doing so, or you used too much water or the plaster was not ok.

 

[Biff Superman]

Try painting a thin layer of latex over your armature before you sculpt. Let it dry then put the clay over that. Your armature will pull away from the clay with ease when demolding.

 

[DarkHelmet]

Like others have said, it's almost impossible to get your sculpt out clean from a plaster mold but if your mold is breaking, it's too thin and you don't have the proper burlap reinforcement.

I haven't used WED clay in a while and when I did, I just used a clear coat that worked pretty well. I now use med Monster Clay and use Pledge as a release.

Definitely use at least Hydrocal. I use Ultracal30.

Here is a picture of my last Ultracal mold:

If you have the financial means, I highly recommend the Stan Winston online school.