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Chemistry / Re: Permanent mold material for silver/copper casting
« on: 04/12/2014 23:09:58 »
Thanks for the reply! Well, tungsten wouldn't work for me as I'm looking for a mold material that can "pour" or form around an object that I want to replicate (either a wood carving or a natural object like an acorn). I'm not intending to carve the mold out of a block of tungsten or other material - I'd like to realistically capture the shape and texture of the object I'm casting from an original (such as that acorn).
That's why I'm wondering about a cement compound or clay material that can form around the object. If cement, I'm thinking I could pour half the mold around one side of the acorn, let it dry, then coat the cement surface with a substance to prevent bonding or sticking. Then I'd pour cement onto the dried face of the first batch of cement (and now fully encasing the acorn), let it dry and pull the two halves apart, remove the acorn. Presto - I have a mold! But will molten silver melt away or chip the cement? Hence my conundrum.
That's why I'm wondering about a cement compound or clay material that can form around the object. If cement, I'm thinking I could pour half the mold around one side of the acorn, let it dry, then coat the cement surface with a substance to prevent bonding or sticking. Then I'd pour cement onto the dried face of the first batch of cement (and now fully encasing the acorn), let it dry and pull the two halves apart, remove the acorn. Presto - I have a mold! But will molten silver melt away or chip the cement? Hence my conundrum.