[TheForge] Small gas forge

[Dave Brown]

I'm going to make a small gas forge with naturally aspirated burner (i.e. 
Bunsen Burner).  For the case I'm using a metal housing from an old GE 
3/4hp electric motor.  It's 6.5" diameter, 7.25" long.  It will be lined 
with 1" Kaowool giving it a net 4.5" diameter.  Interior volume will be 
affected a little bit because I plan on using a piece of fire brick or 
piece of ceramic on the bottom for a floor.  Heck, I may even put in a hard 
cast refractory floor using some Mizzou (A.P. Green) refractory cement that 
I have handy.

Now the questions:

1.  Will a burner using a 3/4" pipe be overkill for this small forge and 
should I consider making a smaller burner from 1/2" tubing/pipe?  The 4.5" 
net diameter (after putting in the Kaowool) is a lot smaller chamber than 
the 8" or so diameter in the more typical propane forges using the 3/4" 
pipe Bunsen burners (about 1/3 of the larger size).

2.  Would the burner tip from a propane torch (e.g. Bernzomatic type) be 
adequate so I wouldn't need to build a burner?  I saw a small "bean can" 
forge set up this way, but it had only a 3" ID and6" length.  Going up to 
4.5" ID with 7"+ L is a more than 260% increase in volume.  I'm thinking 
that may be a bit much for the propane torch to deal with.

I suppose I could make one using the torch tip and if it doesn't work just 
upgrade to a 1/2" pipe burner.  I just wanted to think out loud here and 
see what opinions or similar experiences might be floating around here.


Dave Brown
Heritage Smithing
Green Bay, WI
ABANA, UMBA, GoM, MODA, ARG