Note on quenching oils after a trip to a forge demo in Ohio
Honestly, I went to a blacksmithing demo last weekend at a small farm in Ohio, and the guy running it talked about how his quenching oil went bad after just 3 months. He said he didn't filter it regularly and it got all sludgy, which messed up his hardening on a batch of 10 knives. I always just assumed oil lasts forever, but now I'm checking my own bucket every 2 weeks. He recommended running it through a fine mesh strainer after each use, which sounds simple but I never thought to do it. Has anyone else dealt with oil getting too thick or dirty over time?