PSA: My master smith told me to quench in used motor oil and I regret it

Been at this for 2 years and my mentor swore used oil worked best for heat treating. Tried it last month on a high carbon blade and got a terrible warp plus that burnt smell stuck to everything. Anyone else had a mentor give them advice that went bad?

3 comments

3 Comments

ruby_rivera761mo ago

Honestly I was on the opposite side of this until I tried it myself. Used to think old timers knew best and swore by used motor oil for everything. Then I did a batch of 1095 blades and the smoke was insane plus the edge hardened unevenly. Switched to a proper canola oil quench and the difference is night and day. Your mentor probably meant well but that advice is outdated for sure.

lisak261mo ago

Ngl I learned the hard way too when my first blade came out looking like a potato chip and I spent a week trying to convince my cat the smell was just 'antique workshop aroma'.

fisher.adam1mo ago

And this is exactly how it goes with so many old school tips. People pass down stuff they heard from their grandpa without ever testing it against modern methods. It's like how everyone swears by leaving your car running to warm it up in winter but newer manuals say it's actually bad for the engine.