Polishing the parts isn’t hard. The screws, wedges, ejector heads and triggers were polished successively with 320, 600 and 2,000-grit paper for a quick high polish (I skipped grits in between on the screws). The wedge—with its large surface area—required the in-between steps of 400 and 1,200 grit. Back coarse grits up with a small file if any deep scratches are present (wood otherwise), and back up the finer grits with a hard felt pad (Brownells has them in the stock refinishing section).
After the polish, they’re ready to go. No fingerprints allowed! Use Gun Scrubber, mineral spirits or Dawn dish detergent if needed—just make sure the parts are dry before immersion!
Brownells’ cheap iron wire is soft, easily bent around the parts. Set a small can of water off to the side for a quench. The pot can heat the salts much hotter than necessary, so a lead thermometer will allow you to control the temp. Slightly hotter (around 650 degrees F) than the color you want speeds things up. My pot reached 650 turned just under “5” on the dial. At the right temp, you can air cool the parts, but the quench is important to stop the color otherwise.
Once the nitre salts are dissolved, scoop off the pink scum and discard it in an old coffee can. Dip the part (the solution will be mostly transparent), pull it out and look at it (having a work light near the pot helps). You’ll see the part progress as it comes to temperature from yellow to light purple to peacock blue. If the color isn’t right, polish it off and do it again.
Small parts come up to color in just a few seconds. The wedge took about 20 seconds. I often just hold small parts with needlenose pliers. The pliers also act as a heat sink so small screws come up a little more slowly. Just be sure to dry the pliers well each time! Dry and oil the parts with good ol’ 3-in-1. Brownells recommends letting them sit for a day or so, and if they were large parts I probably would, but I’m a little impatient. I found no downside to turning in the screws. Each gun took just a few hours from start to finish. Handy tip: Have a small magnet you can lower into the pot if you drop a screw.
I wear the same safety gear I do when I’m bullet casting: leather work gloves, safety glasses (minimum) or full face shield (preferred), gloves, apron, longsleeve shirt and long pants. Remember: You have quench water near the part, and really high temps+water create an extreme splatter hazard. Do not put wet parts or tools in the salts! Keep a towel nearby.
One thing about the polish. If you want an electrifying look, polish to the high grits, but the blue is very fragile and wears easily. If you want the blue to be more durable, stop at 600 grit and polish to blend the scratches. The blue will last longer since it will be deeper in the metal. Some spin the screws in a drill, but I prefer the look when polished fore and aft with the grain.
