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.