LeFusil is straight on about the potassium nitrate heat coloring.
I totally agree, thank you Lefusil and bushveld.
I've always loved the colors produced by nitre bluing, but have been reluctant to try it because of the associated dangers.
I think that, for the amateur like myself, the method I've tried is a relatively low-cost, low danger way of doing heat bluing.
What I didn't understand. until I started this thread and thought about the replies, was the mentality that I had when I was torch
bluing versus this method. With torch bluing, once I had the color I wanted, I would stop immediately, here once the temperature
is stabilized that you should keep the piece at that temperature for several minutes.