My uncle told me to always quench a hot punch in used motor oil

He said it would make the tip hold up better... so I tried it on a set of center punches last fall. The oil caught fire and I had to throw the whole bucket in the dirt. Turns out he was mixing up old advice for hardening with a real quench tank setup. Anyone know a safer way to harden small tools without a full forge quench?

3 comments

3 Comments

ray8162mo ago

Bacon grease? That's a new one. The smell alone would drive me out of the garage. I can't imagine trying to explain that to anyone who walked in. Your grandpa must have had a strong stomach for that kind of thing. It sounds like the old methods were just about using whatever thick oil was on hand.

rosed322mo ago

Remember my grandpa hardening a screwdriver in a can of old bacon grease. The smell was awful but it actually worked.

benflores1mo ago

The bacon grease thing is interesting but what nobody mentions is that old timers like @rosed32's grandpa were basically doing crude hot oil tempering without realizing it. That smell lingered for days though, I can still almost smell it reading this.