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. 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