Need newbie help. Any working sealers for sulfur based clay?

New member here and new to latex mask making. So the gist of the story is I'm currently sculpting a Silence (doctor who) bust that I plan on making a latex mask of, however I have hit a major set back. Turns out the guy at the art store I shop at completely steered me wrong as to which clay to use (ended up with roma plastilina) which wouldn't have been an issue had he not convinced me to also buy Rebound 25 for better detail transfer to my mold. I just found out yesterday (via internet research) that silicone and clays that contain sulfur don't mix well at all and that my clay will stop the Rebound from setting.

I have done a lot of internet research looking for a solution and there seems to be a split opinion. Some say there is absolutely nothing that works as a sealant effectively and use a non platinum based silicone, and some say that several layers of Krylon Crystal Clear Acrylic Spray will do the trick.

Am I just out of luck and need to buy a different type of silicone or can I make the Rebound 25 work? I hate the thought that I might be stuck with this Rebound and not able to use it considering I don't have all that much disposable income.

Could covering my bust with non-sulfur clay over the roma be a viable solution? As you can see from the picture below I only have the basic features sculpted out so far and still need to make it bigger to fit my fiance's head.


Silver lining is that I haven't done the fine details yet if this is the most viable option. *facedesk*

You could continue with the clay you have and use Ultra Cal to make the mold, and do Latex pulls of the mask.

What tk1055 said. Brushing latex into a stone mold is much easier than a silicone one. The silicone one would nead a stone mother mold anyway in order to keep its shape. Skip the silicone and go with plaster.

If you are making Latex Rubber Masks then all you would need to do is complete your Sculpt & then mold it with either Hydrocal or Ultracal-30 (I prefer Ultracal-30 because it gives you more working time when making the Mold & it's very strong)...

I'll definitely look into ultracal. The reason why the sales guy told me to get the Rebound was because my sculpture is going to have fine details (like thin wrinkles etc) and he said Rebound 25 works better to incorporate those details into the mold. Plaster would then be placed to reinforce the Rebound mold. Will Ultracal really get into those fine details so that my latex pulls come out as detailed as possible?

Thanks for all the replies by the way. You guys rock!

Roma Plastilina is very good clay and should work well for your sculpt. Yes, you shoudl seal it with crystal clear before molding.

As mentioned above, silicone RTV is terrible for latex casting. A gypsum (Plaster) mold is what works best for latex.

When I did my Red Skull in Ultracal30, I signed the sculpt (Monster Clay) with a pointed tool and when all was molded in the Ultracal, it picked up the signature very clearly! The signature was nothing more than light scratch on the original mold. Hope that puts it into some context for you? I was surprised myself.

Wow that put my mind to rest cunningham! I'm amazed that it was able to pick up a light scratch. Definitely sold on Hydrocal now.

Thanks again everyone for all the advice/help!

lotrpippen said:

Wow that put my mind to rest cunningham! I'm amazed that it was able to pick up a light scratch. Definitely sold on Hydrocal now.

Thanks again everyone for all the advice/help!

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Hydrocal has a very fast set time. If you have never made a large mold with it you may have some problems.
Also it is a lot softer, so when cleaning your mold you may risk ruining detail.
Like a lot of other people said, stick with Ultracal, make sure you do a splash/print coat and at least four layers of burlap.
Crystal clear is a good sealer, just make sure to scrub out your mold with acetone before doing latex.
Any left over crystal clear left in your mold will prevent latex from absorbing.
Do you plan on doing a brush up, or slush casting?

Also, chavant and monster clay are great NSP (non sulphurated plasteline) clays to work with.
I would suggest the medium hardness, and with get a convection/toaster oven that can be set below 150 degrees.