Cold Blue

There is nothing like a beautiful deep blue finish. Even matte blue, which needs less attention in polishing, is durable and reasonably attractive. But many times we need to apply a finish to small parts, the muzzle, or just the slide after performing work. The fine art of cold bluing works well for some of this work. With some care, it may even be applied to complete firearms. The hardest part of getting a good finish is polishing the surface. It is best to strip the blue first.

Home concoctions sometimes work but a solution that always works well is Rust and Blue Remover from Brownells. If there is a good bit of bluing left, along with rust, you want to use this solution and allow the parts (or entire handgun) to soak. Of course the handgun must be stripped into basic components most of the time—but not always as I learned in during a quick fix for a shop. I generally find that several applications of the blue remover are needed.

Stripping away the rust and blue finish will allow a close inspection of the underlying metal and you will see what type of Far Top This old Colt is in good shape for its age. Bottom rust, pitting or damage you are facing. Next comes the part of the chore that demands a bit of finesse. Patience is needed in polishing. Take a look at the rust and pits in the handgun. If the pitting is severe perhaps a simple matte finish would be best.

A handgun with a nice high blue finish but having pits is more gaudy than attractive. If a high quality finish is needed then go all of the way in polish. I begin polishing with the roughest grit of sandpaper first. This allows the finish to be worked with the sandpaper and rust and burrs removed. Sandpaper from 180 to 400 grit should be cut to 1-2 inch wide strips. I think that if the piece has only a light coat of surface cor-

This is normal when using cold blue. Far I moved to a darker finish in the final product. rosion then 320 grit is a good starting point. I mount the sandpaper on apiece of wood, a straight up square block. Using just the sandpaper, push it against surfaces that are tight and more difficult to get to. Once the ground work is done with 320, polish to 400 grit. I may use finer grit sandpaper if needed. Gasoline or kerosene is used sparingly to wet paper at the 600 grit line, which I like to use on the final finish.

This is time consuming but in the end it works well. When the metal parts are polished they must also be degreased. This is a spot of work that must not be ignored. A lot of grease accumulates in a lifetime of use. Acetone works fine for degreasing. There are commercial mixes from Brownells that have been proven in years of use. I use an old chamber pot—which was never used for the intended purpose in the past fifty years—as it seems just the right size.

This is a neat antique and the finish of the pot was intended to take abuse. It is also mobile and may be taken to the workshop, under an awning, or moved to the laundry room. After a good drubbing with acetone, let the parts set until fully dry. If the acetone isn’t dried completely and the slide or parts not thoroughly degreased you’ll have problems. I let the parts set overnight. This easy enough for me as I always have It hasn’t worn as well as a hot blue finish would but offers reasonable service.

The cylinder and muzzle are well worn.

Among the tell tale traits of such a flubbed project is the smell—the salts were still evident! several projects going and don’t get in a hurry. I most often use acetone and then a commercial mix from Brownells. Lauer Custom Weaponry degreaser ($10.99 at Brownells. com) also works. Finally, I spray the parts with WD-40, which displaces any water and dries quickly. A big advantage of cold blue is that no heat is needed and it works well for some uses.

As an example, I was recently called to a shop to examine a rather decent looking Colt 1908 25 ACP self-loading pistol. The pistol seemed in good operating order. There was a drawback to sales—the pistol had no finish. There were some advantages, though. Despite having no finish, the pistol had no pitting or rust, the metal was very clean and well preserved. If someone polished this pistol they would have a job with me.

The markings were clear and sharp and there were no tell tale whirls from a poorly done polish job. The pistol looked fine other than not having any finish. Despite being in good shape, bare metal isn’t very durable and doesn’t resist rust. I told the gentleman that I could deliver a dark finish that looked OK. The finish wouldn’t resist holster wear but would result in a more attractive pistol.

All that was needed was to carefully put a bit of sandpaper on a pencil and trough out the sight channel as it held the only semblance of the pistol’s old finish. I used the typical acetone/Brownells solution to degrease the gun and then let it set overnight. After drying, I used a clean bathroom rag that had never been used soaked in oil. I have several of these and I don’t mix up the ones that I apply oil with the ones used to apply cold blue.

I soaked the rag and began to move across the long surfaces, getting a nice even polish and then repeating. I paid special attention to the muzzle and the flats of the slide, also watching the safety and grip safety to be certain the application was clean and even. In this case I did not disassemble the piece, first as an economy measure as the customer was on a tight budget and as a learning experience to see how blue applied in this manner to such a small handgun would work.

I was careful to keep the blue even and wiped it back and forth evenly. The darkness of the finish depends on how much you apply to the metal. I kept going until the finish was quite dark and then allowed it to dry overnight. The next morning the finish didn’t look that great after drying, but I applied gun oil next. After running the pistol down at intervals during the day the finish looked nice, dark and even.

The result is a finish that added a considerable amount of resale value to a bare bones pistol with no finish. We would never fool anyone with this as a high-end finish and that certainly wasn’t the intent. But this pistol was not a collector’s item, it is a simple, useful, and reliable small bore pocket gun that someone picked up on the cheap. I lubricated and test fired the pistol with a half box of decades-old Remington UMC ammunition. It cracked off every round, never failing to feed, chamber, fire or eject.

The project turned out well. AG