On Sep 22, 10:48*am, Cydrome Leader wrote:
Jim Wilkins wrote:

This is the stove I anneal and heat-treat in. A piece of steel coated
in Ivory soap and left in overnight cleans up to a smooth grey with
little or no scale. I modified the stove by drilling some small holes

What's this soap process?

Ivory or other sodium stearate soap bakes into a coating that protects
hot steel to some extent. Another old formula I haven't tried is salt
and flour.

Rub the moistened soap on tool steel before hardening it. As long as
the part stays in a reducing flame the cutting edges don't degrade
quickly at red heat, or scale in the air between the fire and the
quenching bath. If I do it right I can sharpen the edges with a Dremel
or hand whetstone rather than having to set them up on the surface
grinder.

I harden small tools with a propane torch angled into a tin can with
some charcoal in it, which contributes enough radiant heat of its own
that the propane flame can get the steel up to hardening heat. When
the steel doesn't attract a weak magnet I dump everything into a pail
of water. The instructions for oil-hardening steel say that water is
OK for small cross-sections.

Do this in a safe place outdoors and don't use a magnet strong enough
to lift the part.