On 16/12/2019 21:23, Vir Campestris wrote:
On 15/12/2019 21:32, Brian Reay wrote:
Vir Campestris wrote:
On 15/12/2019 12:23, Brian Reay wrote:

Ah, I vaguely recall something similar but haven't tried it. I expect
there are many 'old fashioned' methods which work after a fashion.

Maybe I've missed, but the one I recall was dunking the hot object in
oil.

Andy


Oil or water, yes.Â* Mr Murtz, the OP, started there. Case hardening was
suggested as an alternative and this flour thing was mentioned.

Through history, numerous techniques/ concoctions have been used-
including
animal dung I believe.

No, oil rather than water.

You get the rapid cooling _and_ the high carbon surface all in one. Even
if it doesn't make the things harder it looks a lot better than bare
iron does after a couple of years.

Andy

Agreed. Only a thin surface though. And most of the carbon is in a sort
of lacquer on the surface, a bit like the finish of a well used iron
frying pan or pot. It is surprisingly adherent and provides good
corrosion resistance.