[Marc]

I asked my local fried seafood place if I could get some of their discarded frying oil. That's not a problem for them, but the owner said that he uses an animal/vegetable oil. Would that present any problems as a quenchant? I'm most concerned with the oil going bad over time. Does the animal part of it get "ripe"?

I'll only be using this on occasional junkyard steels, like 4140 and 5160 (or whatever crosses my path), for hammers, treadle hammer tools, etc.

--Marc