Bluing is most commonly used by gun manufacturers, gunsmiths and gun owners to improve the cosmetic appearance of and provide a measure of corrosion resistance to their firearms. It was also used by machinists, who protected and beautified tools made for their own use. Bluing also helps to maintain the metal finish by resisting tangential scratching, and also helps to reduce glare to the eyes of the shooter when looking down the barrel of the gun. All blued parts still need to be properly oiled to prevent rust. Bluing, being a chemical conversion coating, is not as robust against wear and corrosion resistance as plated coatings, and is typically no thicker than 2.5 micrometres (0.0001 inches). For this reason, it is considered not to add any appreciable thickness to precisely-machined gun parts.
Bluing may be applied, for example, by immersing the steel parts of the gun to be blued in a solution of potassium nitrate, sodium hydroxide, and water heated to the boiling point, 275 °F to 310 °F depending on the recipe. Similarly, stainless steel parts of the gun to be blued are immersed in a mixture of nitrates and chromates, similarly heated. Either of these two methods is called hot bluing. There are many other methods of hot bluing. Hot bluing is the current standard in gun bluing, as both it and rust bluing provide the most permanent degree of rust-resistance and cosmetic protection of exposed gun metal.
Rust bluing was developed between hot and cold bluing processes. It was originally used by gunsmiths in the 19th century to blue firearms prior to the development of hot bluing processes. The process was to coat the gun parts in an acid solution, let the parts rust uniformly, then immerse the parts in boiling water to stabilize the rusting process by removing any remaining residue from the applied acid solution. Then the rust was carded (scrubbed) off, using a carding brush or wheel. A carding brush is a wire brush with very soft, thin (usually about .002 thick) wires. This process is repeated until the desired depth of color is achieved or the metal simply will not color any further. This is one of the reasons rust and fume bluing tend to be more rust resistant than any other method. The parts are then oiled and allowed to stand overnight. This process leaves a deep blue/black finish.
Fume bluing is another process similar to rust bluing. Instead of applying the acid solution directly to the metal parts, the parts are placed in a sealed cabinet with a moisture source, a container of nitric acid and a container of hydrochloric acid. The cabinet is then sealed. The mixed fumes of the acids will produce a uniform rust on the surface of the parts (inside and out) in about 12 hours. The parts are then boiled in distilled water, blown dry, then carded, as with rust bluing. These processes were later abandoned by major firearm manufacturers as it often took parts days to finish completely, and was very labor intensive. It is still sometimes used by gunsmiths to obtain an authentic finish for a period gun of the time that rust bluing was in vogue, analogous to the use of browning on earlier representative firearm replicas. Rust bluing is also used on shotgun barrels that are soldered to the rib between the barrels, as hot bluing solutions would dissolve the solder during the bluing process.
There are also methods of cold bluing, which do not require heated solutions. Commercial products are widely sold in small bottles for cold bluing firearms, and these products are primarily used by individual gun owners for implementing small touch-ups to a gun's finish, to prevent a small scratch from becoming a major source of rust on a gun over time. At least one of the cold bluing solutions contains selenium dioxide, to accomplish the bluing. Cold bluing is not particularly resistant to holster wear, nor does it provide a large degree of rust resistance. It does, however, often provide an adequate cosmetic touch-up of a gun's finish when applied and additionally oiled on a regular basis, however, rust bluing small areas will often match and blend better and wear better than any cold bluing process.
Parkerizing, bonderizing, phosphating, or phosphatizing is a method of protecting a steel surface from corrosion and increasing its resistance to wear through the application of an electrochemical phosphate conversion coating. Parkerizing is usually considered to be an improved zinc or manganese phosphating process, and not to be an improved iron phosphating process, although some use the term parkerizing as a generic term for applying phosphating (or phosphatizing) coatings that does include the iron phosphating process.
Parkerizing is commonly used on firearms as a more effective alternative to bluing, which is another electrochemical conversion coating that was developed earlier. It's also used extensively on automobiles to protect unfinished metal parts from corrosion.
The Parkerizing process cannot be used on non-ferrous metals such as aluminum, brass, or copper. It similarly cannot be applied to steels containing a large amount of nickel, or on stainless steel. Passivation can be used for protecting other metals.
The process involves submerging the metal part into a phosphoric acid solution whose key ingredient is often zinc or manganese, with varying additional amounts of nitrates and chlorates and copper. In one of the many processes that have been developed, the solution is heated to a temperature of 190–210 °F (88–99 °C) for a period ranging between 5 and 45 minutes. A stream of small bubbles is emitted from the metal part as the process takes place; when the bubbling stops, the process is complete. In addition to this particular processing temperature, there have also been various similar Parkerizing processes developed and patented that permit using either lower temperatures (for energy efficiency) or higher temperatures (for faster processing).
The Parkerizing reaction equation in a metal-phosphate-solution is as follows:
2 Fe(s) + Fe3+(aq) + 3 H3PO4-(aq) → 3 FePO4(s) + 3 H2(g)
Cerakote™, state-of-the-art, firearm coatings provide a durable, weather and corrosion-proof, ceramic-based, protective finish that resists scratching, chipping, abrasion and chemical cleaning solvents. Hardener and paint chemically bond into an ultra-thin coating that adheres to almost any surface for a clean, professional finish.
Duracote Paints provides a protective paint finish that won’t chip, crack, or flake; works great on any material. Hardener and paint form a chemical bond for durability and elasticity.
Teflon/Moly, is a great looking coating with the increased durability and friction-fighting properties of Teflon® fluoropolymer resin and molybdenum disulfide that can be applied to any firearm or metal part. As the metal heats, its pores open allowing the Teflon component to penetrate. On high-wear areas, like slide rails, the coating will eventually wear away but the Teflon will still be in the pores, lubricating and protecting. Plus, dense colors won’t lighten, dissolve or break down under all common gun solvents. One application makes any properly prepared metal almost impervious to oxidation.
While walnut is the favored gunstock wood, many other woods are used, including maple, myrtle, birch, and mesquite. In making stocks from solid wood, one must take into account the natural properties and variability of woods. The grain of the wood determines the strength, and the grain should flow through the wrist of the stock and out the toe; having the grain perpendicular to these areas weakens the stock considerably.
In addition to the type of wood, how it is treated can have a significant impact on its properties. Wood for gunstocks should be slowly dried, to prevent grain collapse and splitting, and also to preserve the natural color of the wood; custom stockmakers will buy blanks that have been dried two to three years and then dry it for several additional years before working it into a stock. Careful selection can yield distinctive and attractive features, such as crotch figure, feathering, fiddleback, and burl, which can significantly add to the desirability of a stock. While a basic, straight grained blank suitable for a utilitarian stock might sell for US$20, an exhibition grade blank with superb figure could price in the range of US$2000. Blanks for one piece stocks are more expensive than blanks for two piece stocks, due to the greater difficulty in finding the longer blanks with desirable figure. Two piece stocks are ideally made from a single blank, so that the wood in both parts shows similar color and figure.
Once the wood surface is prepared and stained, a number of coats of finish may be applied, often sanding between coats. Commonly used wood finishes include wax, shellac, drying oils (such as linseed oil or tung oil), lacquer, varnish, or paint. Other finishes called "oil finish" or "Danish oil" are actually thin varnishes with a relatively large amount of oil and solvent. Water-based finishes can cause what is called "raising the grain" where surface fuzz emerges and requires sanding down.
Finally the surface may be polished or buffed using steel wool, pumice, rotten stone and other polishing or rubbing compounds depending on the shine desired. Often, a final coat of wax can be applied over the finish to add a slight amount of protection.
Hydrographics or HydroGraphics, also known as immersion printing, water transfer printing, water transfer imaging, cubic printing, or hydro dipping, is a method of applying printed designs to three-dimensional objects. The hydrographic process can be used on metal, plastic, glass, hard woods, and various other materials. In the process, the substrate piece to be printed is pre-treated and a base coat material is applied. A polyvinyl alcohol film is gravure-printed with the graphic image to be transferred, and is then floated on the surface of a vat of water. An activator chemical is sprayed on the film to dissolve it into a liquid and activate a bonding agent. The piece is then lowered into the vat, through the floating ink layer, which wraps around and adheres to it. After removing the piece from the water, a top coat is applied to protect the design. With multiple dippings, hydrographics printing can achieve full 360° coverage of the part surface, including small crevices.
Custom artwork is available upon request.