Home Forums Hunting & Shooting Gunsmithing Ever tried to do a cold rust blue at home ?

Rust bluing is probably one of the easiest things for a home gun worker to accomplish with highly successful results. It really only requires patience and attention to detail. Investment is minimal, and required equipment can be purchased or made without prohibitive cost. Bluing small parts and gun furniture (grip caps, buttplates, triggerguards, etc...) can be successfully blued with equipment virtually any kitchen currently contains. The only purchase required in that case is the rust bluing solution, gloves (cotton or latex), and cotton applicators. Caution........some cotton balls are impregnated with stuff which will spread an oily substance when applying solution.

I used Mark Lee's #3. I used a stainless tank for boiling barreled actions with a three burner heat source. I also built a humidity box with a light bulb heating source over a shallow water container. A second light bulb on a rheostat higher in the box to adjust for humidity that may cause condensation. You will certainly have to adjust the humidity box for the area of the country and time of year you are bluing. My free time for bluing mostly happened during winter time in Wisconsin, so I was generating more humidity in the box than would ever be required in other areas of the country.

I degreased with Simple Green cleaner and boiling water. I hand polished to 320 grit.........with backing. After degreasing, the metal parts are never handled without gloves. I also changed gloves frequently.

The very first application of rusting solution can be applied aggressively. It can be rubbed in liberally, but not left excessively wet or dripping. Then the metal is set in the damp box for rusting. You must get a feel for how long rusting is required. Check frequently to see when orange rust is developing. Allowing to rust too long will develop pitting. Better too short than too long. It just may require more rusting sessions. After the rusting session, the metal is suspended in the boiling tank of distilled water. This boiling will convert the orange rust to a black "fur". At the conclusion of boiling, remove the metal part and immediately blow it dry with a hair dryer. Any dripping water has the capability of creating a stain if not blown dry quickly. I carded off the black fur with a fine wire stainless brush (degreased) in my variable steel drill. If you have a bench buffer, so much the better. This first session will invariably look like crap. Don't be discouraged.............it's the first of 7-8 iterations.

The 2nd, and further applications of bluing solution, must be applied with a gentle hand. Float the applicator in overlapping strokes, just leaving a damp covering on the metal. Think in your mind that every successive application will be applied with less pressure, and less solution. Applied bluing solution can remove bluing that is on the metal. Some metals will require more sessions than others, but in 30 years as a hobby, I've not found one that wouldn't ultimately take a good rust blue.

To get a feel for what this procedure entails, blue some small parts. You can boil them in a pan on the kitchen stove, and a temporary damp box can be accomplished by using a plastic container, with vented or cover ajar. Place a small shallow dish of hot water in the corner to provide humidity. You can see the rust developing, and boiling off and carding is pretty simple. It will work. Degrease. Apply solution as described above. Handle only with gloves. Provide some humidity while rusting.......not so much that condensation develops.

Some people have successfully carded with degreased steel wool. I never got comfortable with that method, but know it will work, and a brush wheel is one less thing to purchase.