"Maximum Temperature Possible With "Mold Builder" Latex?" Topic

This is the latex I have at home. It is available at most craft stores:

link

I would like to know if I can make a latex mold of a small SF terrain piece I made, and then use it as a push mold and fill it with Sculpey (or other polymer clay), and bake in the oven to about 270 F for 10 minutes. It would be great if I could get 3-4 Sculpey casts out of it.

link

Would that temperature destroy the latex mold, or have it melt into the Sculpey? I'm hoping not to go into additional expenses by purchasing a different mold material. I would rather use materials I already have at hand.

Thanks,

Dan
PS. I know I could make the casts using plaster that I already have at home. However, I was hoping for something more resilient than plaster. And I have lots of Sculpey around.
TMP link

I think that either the heat would destroy the mold, or the hot Sculpey would bond to the latex. Either way, not good.

If that latex is strong enough for you to push the Sculpey into it, then must remove the Sculpey and bake it out of the mold.

For example, I have an old mold from Dunken that is very tough. I can knead Sculpey until it's soft and use that mold as a push mold.

But I also have a softer Woodland Scenics rock wall mold, and if I try to push softened Sculpey into that, it deforms and all of the sharp detail is lost. No good for push-molding.

Well a latex mold probably would be stiff enough to make a push mold out of in a reasonable amount of time. With a mother mold backing it…

You can bulk/strengthen them by adding gauze to later layers (3rd or 4th).

That being siad you can build up the mold and once the latex part is done you can make a plaster mother mold for the back of the latex on to give something to push against.

As for temperature, latex is frequently "vulcanized" by boiling it in water for a time. So at least temps up 212 degrees. So a longer slow bake might be possible.

Make a test mold and try it out.

Mind you latex is on the soft side, so push may not work very well, though brushing on some liquid sculpy and curing it then backing it up with another layer of liquid then some very soft clay and curing again might do the trick.

Infojunky: "brushing on some liquid sculpy and curing it then backing it up with another layer of liquid then some very soft clay and curing again might do the trick."

Brilliant idea!

Thanks so much. I'll test it with a small trial piece first.

Dan

Take a look at this…

PDF link

Maybe look for more info here:

reynoldsam.com

Taken off the hirst art site

"I used to use high quality plaster for all my modelling, but later found out that the highest quality plaster is more or less a mixture of cheap plaster and concrete. I've experimented with this and found that 3 parts plaster of paris mixed with 2 parts concrete will have almost the same durability as dental plaster, but costs only as much as plaster of paris.

Plaster of paris and concrete are about the same price, you just have to buy twice as much for twice the price- even this is usually cheaper than going straight for the quality products. So long as you don't put in too much concrete (no more than 2 fifths for walls, etc… and about a quarter for detailed work) it will have the same quality as dental plaster. -Toomy"

Don't use sculpty. Use the real stuff.

This is what they say…..

"The temperature will destroy the latex, I would not use it over 100F
You may be able to find a silicone rubber that will take the heat but we do not sell it, sorry."

John

Delvie's Plastics Inc.
8am to 5pm M – F Mountain Time
800-533-5843
delviesplastics.com

Another option is to take plaster of paris and use it to make a backing mold for the latex. That will strengthen the latex structurally and allow you to push sculpy into it.

"concrete"? As in neat cement/grout? I can't see Hirst molds and pea gravel getting along at all well.

I think he was referring to Portland Cement in it pure form, with out the sand and gravel