ArtMetal

I was thinking of buying my own oven/furnace for casting my own railheads, models etc. I know nothing about making casts but I think it could be really interesting. I have my own free supply of Rebar free of charge and was thinking of making good of it.
Any ideas would be appreciated. Read some previous articles on casting and rebar is not too bad apparently and seeing as though I can get it for free it could be interesting. Any advice appreciated.