"pintlar" wrote in message
...
I take it you screw the second cap on 'very loosely' to prevent an
explosion in the forge.

Nope! You don't want any oxygen to get in. The amount of carbon you put in
is much more than needed for both hardening and combining with any residual
oxygen in the pipe. I use a similar method for annealing. Making small
tools from allen wrenches or concrete nails, I put them in the pipe with 3
to 6 sq. inches of brown paper to get rid of residual oxygen, and put the
pipe in the fire as Bob does. After the pipe gets to temperature, let the
fire die out. When all is cool, nice non-scaled annealed steel.

Bob