Making detailed moulds for metal casting, what to use? modeling clay?silicone rubber? or what?

I want to use something that will pick up even the smallest of details. Any suggestions on whats best to use





tiaMaking detailed moulds for metal casting, what to use? modeling clay?silicone rubber? or what?
I'm not sure what the best mold materials are for casting metals since they get so incredibly hot when melted, but the link given above is to a lesson on making a mold from a 2-part silicone putty and various brands of that stuff will take 300 degrees F and some more like 800 (and silicone putties produce very fine detail in molds). That link also uses ';metal clay'; in the finished mold to shape the clay, but it must be removed before curing because that type of clay has to be heated at high temp in a kiln (';metal clays'; are real silver though so could be used that way, then burnished after removal and a trip to the kiln or butane torch, for small items but it is quite expensive).





The DH tells me that perhaps pewter or pewter-like materials melt at a low enough temp that they could be cast in silicone putty molds, but for gold and silver you'd probably use plaster molds (and perhaps a lost wax process), and for higher temp or larger things you'd use very-fine-sand molds.


It would help to know exactly what kind of thing you're wanting to cast and their size, plus the kind of metal you're interested in though.





Check out the links in this search for lots of info on casting metals in various ways:


http://www.google.com/search?q=how+to+ca鈥?/a>








P.S. You can also create very realistic simulations of metals (for figures, jewelry, other items, etc) with ';polymer clay'; (Fimo, Kato Polyclay, Premo, Cernit, Sculpey, etc).


Before or after it's hardened --in a home oven at low temp-- depending on material added, the clay is treated with real-metal powders or real-metal leaf, or with mica-based powders and paints which give a little softer metal effect, or with various metallic waxes.


Also, polymer clay can be cast in molds of all types, or it can even be made into molds itself for use with more clay, but can't take temps higher than about 350 F without burning.





If you're interested in any of that, check out these pages at my polymer clay website:


http://glassattic.com/polymer/molds.htm


http://glassattic.com/polymer/Faux--many鈥?/a> %26gt; Metals


http://glassattic.com/polymer/powders_me鈥?/a>


http://glassattic.com/polymer/leaf.htm








HTH,





Diane B.Making detailed moulds for metal casting, what to use? modeling clay?silicone rubber? or what?
I think Clay
casting plaster try walshes birmingham The highest detail comes from adding a vacuum to the casting process