Eric, you can use any oil you can get, be that animal, vegetable or
I use old sump oil, as I have lots of it (I change my own oils on
bikes/ute & tractor).
Be warned, used sump oil has some nasties in it, so try not to breath
the fumes. Really that goes for all oils.
you could buy new cheap motor oil if you liked. I have read of people
using automatic transmission fluid, but I don't know how well it works.
I have a friend who uses vegetable oil, the cheapest he could get at
As to Animal, well I have used whale oil, at the local community
college (called TAFE) which used to teach blacksmithing, they had it
left over from the 50's. Also Wayne Goddard, the knife maker, used a
mixture which contained bacon fat - if I remember correctly, I could
look it up, if you need me too, it was in his book on the $50 knife
What it comes down to is, use what you have or can afford. Just try
not to use something that is really thick, high viscosity, I'd go
thinner if I were you. I remember reading somewhere that a ligher oil
works better, particularly when you have such thick material to quench.
Please let us know what you use and how it works.