This sounds interesting. Like all interesting thing, there is a catch -- safty.
I have not done any casting except for sinkers (fishing), but I used commercial
electric heater ( I forget what is the proper name for that gadget) and a manufactured mold -- I guess that does not count. However, I have heard the danger for casting -- spills when tong slips; mold explodes because water (in sand mold) vaporizes when comes in contact with hot molten metal.. etc.
Don't get me wrong, I'm not trying to discourage anyone.
I have in my past rig up a forge to do some blacksmithing with a BBQ kettle, fire bricks and a hair dryer. It works and a lot of fun, but also created a mess to clean up.
An alternate method to casting is blazing / soldering. Grind / file the metal pieces to shape, clamp them together and blaze with oxypropane -- kits available in any hardware store.