Cut a length of soft wire longer than the gun barrel so that it is long enough to protrude from either end. After threading the wire through the barrel, bend both ends into hooks that can be grasped without touching the barrel and be suspended on hooks or a length of cord or wire outside of the chemical baths. Smaller parts can be held in a stainless steel basket.
One chemical cleaner that was reportedly discontinued contained sodium metasilicate, found in a number of commercial floor strippers. [2] X Research source A cleaner that can be used in its place is sodium triphosphate, a component of a number of commercial detergents. [3] X Research source Some bluing product manufacturers recommend using naphtha, followed by washing the metal in a mild dishwashing detergent. [4] X Research source Some hobbyist ‘bluers’ use a special cleaning oil, followed by acetone (nail polish remover) to clean the metal, while others use denatured alcohol. [5] X Research source (One such cleaning oil, a mixture of mineral and vegetable oils, alcohol, alkaline salts, and benzyl acetate, is sold commercially under the name “Ballistol. ”)[6] X Research source
If you’ve used dishwashing detergent to remove the cleaning chemical, you may instead need to use hot water to rinse. [7] X Research source
Before heating the bluing solution, stir it thoroughly to break up any clumps of bluing salt that may occur on the surface or at the bottom of the tank holding the solution. When dipping gun barrels in bluing solution, dip them at an angle to allow any air bubbles that may form to escape. Be sure to immerse the barrel completely. Swirl the metal basket containing smaller gun parts around in the solution to ensure the parts are completely coated with the bluing solution. Leave the gun parts in the bluing solution from 15 to 30 minutes. Check to see when the metal has reached the desired shade of bluing and remove it from the solution at that time. Stainless steel gun parts are immersed in a different chemical solution, this one made of a mixture of nitrates and chromates. It is heated to temperatures similar to the nitrate-hydroxide mixture. [9] X Research source
If the gun has any soldered parts, you can apply a chemical to these parts that will color the soldering to match the rest of the metal. Use a cotton swab for this.
If you plan to remove the gun’s finish from the factory before bluing, some recommend using a phosphoric acid-based automotive rust remover to do so. Others use white vinegar, which contains acetic acid, for this purpose.
Instead of coating the parts with the acid solution, you can instead place an opened container of the acid solution with the gun parts in a cabinet and seal it for a period of 12 hours. The acid evaporates from its container and condenses around the gun metal. This method is called fume bluing. Another variation is to coat the gun metal parts with the rust bluing solution and then put them into a fume cabinet (or, in this case, a damp cabinet) for the same 12 hours. Often, a first layer is applied as a primer before coating the parts a second time and then placing them in the damp cabinet. [11] X Research source
If you plan to blue the entire gun, you may want to immerse the metal in a cleaning solution as described for the hot bluing process. If you plan to just touch up existing bluing, you can apply cleaning oil to the places where you want to remove the old bluing and prepare the metal for cold bluing. (The cleaning oil will dissolve existing bluing if applied excessively. ) Use acetone on cotton balls to remove the cleaning oil. You may have some scarring from this process that will require sanding or polishing out.
For applying the bluing to large areas, old all-cotton T-shirts or new toothbrushes are recommended. For smaller areas, use a cotton ball, cotton swab, or flat toothpick no larger than the area to be covered. You can soak small parts like screws or hard to cover areas in the bluing solution. If you don’t have enough bluing solution to soak a recessed area, put it in a clean spray bottle and spray it liberally on the part over a glass pan or plastic tray. After the part is completely covered, you can pour the overspray back into the bottle and reuse it.
The more layers you apply the darker the bluing will be; however, each new layer is progressively less effective than the layer before it. Seven layers should be enough, in most cases, to achieve a dark blue-black finish. [15] X Research source If you have spots that won’t darken, start the process over by sanding the spots with 320 to 400-grit sandpaper before applying the solution again. Try to sand no more than the stubborn spots themselves.
Do not use the cleaning oil for this process, as it will take off the bluing you worked so hard to put on. [16] X Research source
