[ithacaartist]

One way of getting uniform colors from heat onto parts is to immerse them in a container of sand that's been tempered to the correct temperature. This entirely eliminates any worry about over-heating. A toaster oven works fine for strawing small parts, but you'l need something with more kick to fire blue, which happens at almost 600 degrees F.

If you know a knife-maker, they'd likely have a small tempering oven. A toomaker's tempering oven, potter's kiln, or a glass artist's annealing oven would also work, as long as they're adjustable.

Quenching in oil is not necessary when heat-coloring parts.