52 Ford
Well-Known Member
I found a "NuWave Induction Cooktop" when I was cleaning out a spare room in the house. It's basically a fancy hotplate. Singe burner, digital controls, induction.
McMaster has a VERY similar looking induction heater for bearings, so my first thought when I saw it was to keep it in the shop to heat big bearings. THEN I saw that it goes up to about 600F. So, since I don't have a heat treat oven, I figured it'd make for really convenient tempering of smaller blades.
There's some sort of sensor that checks to see if there is a pan on the hotplate and cuts it off if you remove a pan. I decided to trick it with a piece of 26 gauge steel sheet to get the knife or bearing or whatever closer to the coils and hopefully be heated directly through induction, versus just the heat conducted from whatever you put between the hotplate and the work piece.
I had a knife that I had messed up a while back sitting by the bench and a reminder of what NOT to do... Blade was basically finished except for some finishing work on the spine of the blade and a bad defect in the tang. Anyway, I had hardened it and cleaned the steel off. I dropped it on the hotplate and it went from about 45 degrees F to a medium straw color in a few minutes. Super even temper throughout. The knife is a near-flat grind with about a 5/64" spine and the blade is about 1" tall at the tallest, so pretty thin.
McMaster has a VERY similar looking induction heater for bearings, so my first thought when I saw it was to keep it in the shop to heat big bearings. THEN I saw that it goes up to about 600F. So, since I don't have a heat treat oven, I figured it'd make for really convenient tempering of smaller blades.
There's some sort of sensor that checks to see if there is a pan on the hotplate and cuts it off if you remove a pan. I decided to trick it with a piece of 26 gauge steel sheet to get the knife or bearing or whatever closer to the coils and hopefully be heated directly through induction, versus just the heat conducted from whatever you put between the hotplate and the work piece.
I had a knife that I had messed up a while back sitting by the bench and a reminder of what NOT to do... Blade was basically finished except for some finishing work on the spine of the blade and a bad defect in the tang. Anyway, I had hardened it and cleaned the steel off. I dropped it on the hotplate and it went from about 45 degrees F to a medium straw color in a few minutes. Super even temper throughout. The knife is a near-flat grind with about a 5/64" spine and the blade is about 1" tall at the tallest, so pretty thin.
