I was recently asked to do a forging demonstration workshop at the local wood guild. Not wanting to drag my forge over, I used it as an excuse to make a mini-forge. I used a bit of 165mm 4mm pipe for the body, kept it simple without a door. Needed a back, some channel for the front leg, a bit of angle pipe and rod for the handle and a ring at the front to hold in the lining. I made it fit my existing venturi burner. It took about 3 hours to make, including lining and painting. Not bad for an afternoon's work.  I cut up a bit of fire brick to protect the inside and give something to rest it on, and used another half brick for a door,

It gets very hot on only 20 kPa, enough for forging and heat treating. It looks like it could weld, but I'll save that for the bigger forge so I don't wreck the lining. It's quick, quiet, hot and doesn't use much gas.