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can one cast aliminum into a silicone mould? Answered

I am looking for a quicker & smother way of casting aluminum & have been advised to use silicone but according to what I have read --- the temperature of molten aliminum is to high for a silicone mould! True or false?


If anyone could help me on this but would plaster of paris with sand work?


5 years ago

siliconghost might want to read that again. Your link says 300+. I'm not sure if there is silicon rubber that melts over 600 but I can tell you for sure that the cheep molds you see in the stores will handle 327.5° C+.
This is a guy casting lead in one of the cheep silicon ice cube trays/molds.

OK same guy same mold, zinc this time. 419.5° C

I say go for it and tell us how it ends up but be prepared for total failure.

maybe. I used 2 parts silicone caulk mixed with 1 part mineral spirits and 2 parts cornstarch, dried for two days, then hit it with a blowtorch. It held up fine, though a little discolored. I would try it, but make sure that there's something under the silicone mold to catch the aluminum.

just realised that this is from 2009. Oh well, if anyone else sees this and tries it, tell me how it goes!

check <a href="http://www.backyardmetalcasting.com">www.backyardmetalcasting.com</a> I think th' answer is yes , but if you go to that site and follow th' links you will get a definite answer !

I wouldn't advise it, I'd go on the true side of this choice. L

Use the silicone mold to cast a wax positive. Use the wax positive to do a lost-wax casting to get the aluminum copy.

Ahhhh, brilliant question! Yes, a silicone mold would be great if you want a puddle of molten aluminum on your floor and a smouldering pile of acrid, smoking silicone on top of that. I would just go ahead and find some really fine sand(dustlike if it can be found) and cast in that.

If you are referring to silicone rubber your answer is no.

The melting point of silicone rubber is 300C.
The melting point of Aluminum is 660C

Now if you used actual Silicon (as in the same stuff ICs are made of), that would work as the melting point is 1414C

True, Aluminium is >633 C I can't imagine a silicone taking that. What are you trying to make better ?