Black Bluing

I think a lot of people miss-understand the finishing and bluing process, one miss-conception is that the depth and the blackness of the bluing comes from the brand and quality of the bluing salts, well this is a yes & no answer. The metal must be properly prepped before bluing in order to get the blackness & depth and you must have good quality bluing salts operating at the right temperature, not contaminated or burnt. Bluing tanks must be watched closely so they don’t over heat and burn the salts, as the water boils out the salt concentration becomes higher and boils faster, if this happens the job will come out a reddish rusty color.

Two extreme cases of blue jobs are the Royal Blue on a Colt Python and a Remington Express shotgun.

The Python goes in the same blue tank as the rest of their guns; the high polish prep gives the deep blackish blue luster. This high polish seems to make the bluing stick better offers a high resistance to corrosion penetrates deeper and wears very well.

The Remington Express shotguns look like they are shot peened with playground sand @ 400 psi, all these pits beat into the steel invite corrosion and the blue does not penetrate or stick very well. They have a dull gray finish. If you decrease the receiver on a humid day you can watch it rust right before your eyes. It doesn’t take much effort to rub the bluing off.

Remember with all other things being equal a high polished piece of steel offer some corrosion resistance in itself as apposed to the same steel with a coarse finish.

Some Kimber pistols have a crude metal finish. It appears that after the frames & slides are machined they are rock tumbled or vibrated in big industrial finishers to remove the burrs and machine marks. This is how the fame rails and corners get rounded-off, then they are blasted with the playground sand to give it the texture of an orange, and last the flats are ground. Hand polish work isn’t cheap and if you want to cut-cost this is a compromise.

In my humble opinion, these sand blasters have gotten to be the lazy mans way of polishing something. Just blast everything and blue it for the “matte finish”. They are of the illusion the basting will remove or hide the machine marks.

I have 3 blast cabinets in my shop.

One has pure, fine, white glass bead; this will leave a brighter whiter finish on stainless steel. Under bluing it will leave a dull satin type of finish, kind of like a semi-gloss. The glass is brittle and breaks when it hits the steel and will not peen the steel deeply.

Second; fine aluminum oxide, it’s the next thing hardest to diamond, it is aggressive and sharp. It will cut the steel leaving a very dull, flat, matte, and finish. This works well on the top of hardened slides.

Third; a combination of fine glass & aluminum oxide. I kind of like this finish all-around the best.

Notice I don’t use any coarse grits. Each of the blasting media’s above has a specific purpose.

I don’t use any sand in my shop. It is coarse and leaves a dull matte finish. To me, from the jobs I’ve seen it doesn’t seem to have the blackest finish or keeps it through time.

Keep in mind different manufacture use different types of steels. They all polish and finish differently. Metallurgy wise, for polishing & finishing, Colt has them all beat hands down.

If I want to achieve a matte finish in my shop, first all machine marks are removed (within reason) and the steels is polished, then the surface is dusted-off with the appropriate blasting media. This will give you the desired deep blackish finish. The bluing will hold-up better and be more corrosion resistant than the coarser prep. Remember this is provided we have a good blue set-up.

The black as possible matte finish I like the best for the BLACKEST MATTE BLUE is to black parkerize the pistol first and then blue it over top the parkerizing.

I hope the info above gives you some ammunition for when you go shopping. You have many Pistolsmiths on this Forum that can do your desired finish, just take your pick and give him a call. One smith I know that specializes in this type of finish work is Dave Stagg @ phone # 309-523-2597 I never examined his work finished but I hear his bluing comes out deep black-blue.


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Metal Smith

The only thing I know for sure is what I can measure!
NRA Life Member