Brake drum blacksmith forge - This is how i started out years ago. a word or warning. repeated thermal cycling will mess up a concrete block and in a pretty short time too. Having a forge dump over when one shatters is no fun.
PM's home and auto editors took a weekend out to teach themselves how to heat and hammer metal the old-fashioned way. They started by ordering an anvil and making their own blacksmith forge. The sparks flew from there.