Hello! I have a new question. I'm making a 3D mold of some cured polymer clay items that I've made. I want to use the mold to make "castings" with polymer clay.
My first question is when making the mold do I need to worry about the " Amazing Mold Rubber" sticking to my cured "Sculpey Bake Shop Oven-Bake Clay" polymer clay items? 2nd- one of the items is sorta shaped like a.. Head, basically a ball with a neck on it. Will I be able to make a 1 piece mold and be able to remove unbaked clay when I am making my copies? There are no fine details on this item. 3rd- will the unbaked/uncured clay stick to the mold when I try to remove it? Do I need to use a product to keep it from sticking and if I do which product?
Question #1 - Short answer: no you shouldn't have any problems with the liquid mold materials sticking to baked clay. That being said, I have to ask if the clay has been "sealed" with something. I've never really found a good, easy to pick up sealer for baked clay where I live so I've never had good luck with a sealed clay item. Now when I make my casting "originals", I use clay but I simply bake it (no sealing) before I make a mold of it to cast resin in. Resin is what I use to do any fine sanding/fixing then I use that as my final castings as I make custom candy molds with Plat 25 and it has no problems with the resin castings.
Question #2 - Short answer: again yes you should be able to do this, be aware that you will need to plan out the cuts you'll need to make to be able to put in and remove the clay. BUT for me personally, I would bake the clay before removing it from the mold to make it easies to remove. The mold rubbers (Amazing Mold Rubber, Amazing Mold Putty, and HS 1,2, &3) can withstand up to 395 degrees and clay bakes at 275 so it would be just fine to go ahead and bake the clay right in the mold to prevent any deforming.
Question #3 - Again, I'd go ahead and bake it while it is in the mold myself. Other than that, I'm fairly sure that it will not stick but again - I cast in resin and use the baked clay only in making the mold itself. I believe there is a way to freeze the unbaked clay to give it enough firmness to be removed from a mold but I've not done that myself. Now if you're worried about the clay not releasing from the mold you could always spray/brush on a release agent. For a spray, you could use a fancy release or you could go right to your kitchen and grab a can of cooking spray for food - as it's a type of release for food and will work just as good. Or for the brush on method, all you need is Vaseline - be aware of the drawback of leaving a greasy film on the clay and needing to remove that before baking it.