Metal Casting Zone

I Just made purchase of some oomoo silicone for making a mold for wax casting. The oomoo is neat stuff and easy to work with, they say you can cast pewter directly into it, I have mixed feelings on this I tried it and it kinda melted when casting lead, however I melted a crayon into it and it came out beautiful. Right now the wax pattern is in some investment I made up with plaster of paris and silica sand. I am trying different things out to try and get the investment to take the temp of repeated melts. Right now the plaster is cureing Ill post pics soon and let you know how it works out. If anything the sand will stretch the plaster use out more and cut some costs. The crayons really cut cost lol

Ok well the crayons didnt pan out the way I was expecting. They melt great in a spoon but when you try to burn them out of a mold they dry up into a powder type material.
Didn't see that one coming Maybe use an autoclave? Guess I will be buying some good casting wax this weekend

i read somewhere that cement powder is great mixed in with sand and plaster to make reusable molds i think its in my old pop mech. books from way back.

Ok im making a second attempt at this one, Im trying to reproduce coin I found while out metal detecting, the origional coin is very frail and corroded to where it is jet black. I have made a oomoo silicone mold off the coin and again used crayon for the wax.
This coin is so thin it is difficult to get the waxt to flow into the cavity. it took 4 tries to get the results I wanted. Im doing my split mold trick again with plaster that way i can remove the wax blank instead of having to burn it out. Plaster is setting up as we speak and after that Im putting it into an oven for 24 hours at 500' maybe that will get the moisture out
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Here is the crayon Works out well just have to tinker a bit to get it right
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moving right along, hard to get a pic of the plaster though.
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Crayons have too much color dust in them. See if you can find some candles at a yard sale. That's an interesting coin, hopefully you can get some more detail out of it.
Do you have a website for oomoo? I found it!!
www.smooth-on.com/index.php?cPath=1136

ok I tried to cast it in zinc, still had some moisture in it
I ordered some actual investment up to give a try, If I still dont get the results I want I will be building a burn out oven real soon.
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