We had a 1.5 cubic gas furnace. Water cooled for temper ‘cause we were in Jr High and would have found a way to set the oil on fire. :)
Poor old Mr Poe was the metal shop teacher, He tried to learn us to be frugal and creative
The old penny pincher! LOL
We’d heat up a quarter in the forge and toss that out on the concrete deck.... “He, he, he... got myself a Yowl! quarter!!!”
He’d pick up the quarter with a pair of pliers, quench it and mutter “stupid kids..”
He was a good shop teacher
When all us kids drove Mr Poe nuts, he would take a mental health day.
There, was this goofy sub that came in who wore a toupee
That guy never had a chance.
Chris and I are setting him up, taking hits of oxygen off the unlit cutting torch...
“He’s like what are you boys doing”?
‘sniffing oxygen... Makes you feel good, makes you feel energetic...’
We got that guy passing it around, LOL
Chris says take a BIG old hit and cuts on the acetylene!
That guy turned BLUE
It has been a VERY long time, but oil quenching is the was to go for general purpose tempering.
You are correct about water tempering and crystallizing.
The temperature of the water makes a huge difference, but Oil has a different thermal coefficient and is more forgiving