Hi folks, I'm new to this forum but have been tinkering with cf and ml guns for abouit 50 years. I've come up with a slightly different bluing process that might work for some projects. I have used Brownell's Dicropan I M bluing but WITHOUT the boiling water. You polish however you want it, degrease, then I apply the bluing like the old rust blueing with a tooth brush and brush it pretty good. Let it set for a couple of days then steel wool it off and coat it again. It takes very little blueing for each coat till you get what you want, usually four or five coats. This blueing gives the same black rust coating that the hot imersion blueing does but without the tanks and heat. I used this like the instructions say with the boiling water but had trouble with using unfiltered tap water so I tried this way and it worked pretty well. I've also used small stainless steel brushes to card off the scale but if you are trying for a polished surface you would be better off using steel wool. I've left this stuff on for several days at a time and it seems like it might work better, then a few days after the last coat you should oil it.