I plan to use the monster burner design because of its simplicity and fast melting characteristics.  It has been used in a furnace similar to mine to melt iron.

I have accumulated some of the parts for the burner including the regulator, hose, and fittings for the propane tank.  What I lack is the actual pipe and fittings.  The home improvement stores around here don't keep black pipe and fittings in the 2" range.  I guess I will have to go to an actual plumbing supply house for those.