Jeff and Mike, thanks for your comments about my quench tank. Mike, I've quenched in it three times now; it's been in service for about four months. (It's clear that I've been pretty lazy!

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So far, it's an ideal solution to my "quench quest." The thermostat on the heating element is the critical part of the whole thing, and it really works well. I think I paid something like $80 for it and do not regret the expense at all. Currently I'm quenching at 120F. It will heat the oil from ambient, about 70F, to 120 in about 15 minutes and hold it there indefinately.
The most I've quenched in one session was three knives, but there's sufficient oil in the tank (about 7 gal) that it did not heat up substantially. I think it got to 125 or so quenching the three 'typical' sized knives. Circulating the oil helps with keeping the oil at an even temp, which is what I was hoping for. Originally I thought the pump might be a little light, but it actually seems to be doing a very good job. I'm really pleased with the whole thing.
One nice thing about it is being able to seal the lid. My shop is pretty crowded, so I just shove the tank under my table saw when I'm not using it, and it's out of the way and the oil protected from dust and other crap that might get in it.
The hardest part about the project was getting the Houghton Quench G. Finally the local rep took pity on me and ordered it to his home for me to pick up.
As to whether it will last years ... that I can't say. So far it doesn't give any indication of failure. But if anything does go, and I think the most likely part would be the lightweight pump, repairs should be fairly straightforward. The build was really pretty easy compared to a lot of the things we do.
