Aiming for Protection: An Overview of Firearm Finish Options

June 14, 2023 9 min read

Aiming for Protection: An Overview of Firearm Finish Options

Introduction

Firearm finishes play a crucial role in protecting a gun's surface from corrosion and wear. Although the core material of the gun, typically steel or aluminum, provides the necessary structural integrity, finishes provide an outer layer of protection that enhances and prolongs the life of the firearm. The type of finish used can also impact the aesthetics, feel, and functionality of the gun.

With the wide variety of finishes available today, from traditional bluing to modern ceramic and polymer coatings, selecting the right finish requires evaluating factors like corrosion and scratch resistance, ease of application and maintenance, and desired visual appearance. The finish choice also depends on the type of firearm, its intended use, and environmental conditions it will be subjected to. Understanding the key properties and tradeoffs of different finishes allows gun owners to make an informed decision when refinishing or purchasing a firearm.

This article provides an overview of the most common types of modern firearm finishes, examining the durability, aesthetics, maintenance needs, and typical applications of each.


Bluing

Bluing is a hot chemical process used to rustproof and finish metal firearm parts. It is one of the most common finishes and likely the "default" finish you think of when visualizing a standard pistol or rifle.

The bluing process oxidizes and converts the surface of the metal to magnetite (Fe3O4), an iron oxide that is very stable and protects the metal from rust and corrosion. This is similar to how rust forms on steel over time, but it is a controlled process that creates a uniform dark gray or black finish.

To blue steel parts, they are first polished thoroughly to remove dirt and imperfections that can affect the final result. The parts are then immersed in a hot bluing solution containing various chemicals like sodium hydroxide, potassium nitrate, and sodium nitrate. This initiates an oxidation reaction that forms the protective magnetite layer.

The depth and shade of the blue-black color depends on the temperature, chemicals used, and length of time in the solution. Multiple immersions are often done to produce a darker finish. The parts may also be placed in boiling water between immersions to keep the bluing solution active.

Once removed from the solution, the parts are rinsed, dried, and sometimes coated in a protective oil to prevent fingerprints and handling marks. The bluing provides a nice aesthetic while protecting the steel, though it does require some maintenance to keep the finish looking its best over time.

Bluing Finish{Blued finish on the steel parts of a Chinese AKM}


Nickel Plating

Nickel plating is a common metal finishing process that electroplates a thin layer of nickel onto a metal surface. It offers several benefits for firearms:

  • Corrosion Resistance - The nickel coating prevents corrosion, rusting, and tarnishing. This protects and maintains the gun's appearance over time. Nickel does not react with moisture or sweat like blued steel does. This makes it a popular choice for guns used in wet conditions like hunting or combat.
  • Lubricity - Nickel has an inherently smooth, slick surface that reduces friction. This lubricity allows gun parts to operate smoothly. Nickel plating on high-wear components like slides and bolts decreases wear. The reduced friction also minimizes galling where metal surfaces rub against each other.
  • Bright Metallic Luster - Nickel plating has a shiny, chrome-like appearance when polished. This attractive finish enhances the aesthetics of engraved, customized, or plated guns. The lustrous finish makes nickel a popular decorative choice.
  • Hardness - Nickel plating has a hardness around 400 HV, compared to non-stainless steel at 150-200 HV. This increased hardness provides scratch and wear resistance. It helps maintain the gun's finish over extensive use and handling.
  • Customizable Thickness - The thickness of the electroplated nickel layer can vary from a couple microns to over 75 microns thick. Thicker nickel plating further enhances the protective qualities for highly durable firearm finishes.

Overall, nickel electroplating is an excellent firearm finish coating option. It is decorative, protective, hard, smooth, and corrosion-resistant - ideal properties for functional and beautiful guns.


Stainless Steel

Stainless steel is a popular material for firearms production due to its strength, corrosion resistance, and attractive silvery appearance. There are several grades of stainless steel used for firearms:

  • Martensitic Stainless Steel - This type contains 12-14% chromium and only trace amounts of nickel. It is stronger than other stainless steels but not quite as corrosion resistant. Common martensitic stainless steels used on firearms include grades 410, 416, and 420.

  • Ferritic Stainless Steel - With chromium content between 11-18%, these steels are less strong than martensitic but provide good corrosion resistance. Popular grades include 409 and 430.

  • Austenitic Stainless Steel - Austenitic stainless contains more nickel, with 8-10% nickel and 16-26% chromium. It offers excellent corrosion resistance and is non-magnetic. Common austenitic grades are 303, 304, and 316.

  • Duplex Stainless Steel - As a mixture of austenitic and ferritic, these combine high strength with good ductility and corrosion resistance. Common grades are 2205 and 2507. Duplex stainless is becoming more popular for firearm finishes.

The most common stainless steel grades used are 416, 420, and 304. When compared to finishes like bluing, stainless steel provides greater protection against corrosion and scratches while maintaining an attractive, durable exterior. It offers the strength to withstand repeated firing without erosion of the steel. 

Stainless Steel Finish{Stainless Steel Revolver from Smith & Wesson}


Cerakote

Cerakote is a ceramic-based coating originally designed for the automotive industry/  It comes in a wide range of colors and finishes and is applied through a spray and cure process.

The Cerakote application process begins with thoroughly cleaning and degreasing the firearm surfaces. Any oils, grime, or contaminants will prevent the Cerakote from properly bonding. The surface is lightly abraded to promote adhesion.

Once prepped, the parts are hung on a rack and wheeled into a spray booth. The Cerakote is mixed per the manufacturer’s specifications and loaded into a spray gun. Multiple thin coats are applied, allowing time for each coat to briefly air cure before applying the next.

After spraying, the parts go into a curing oven. Temperatures and duration will vary based on the specific Cerakote product, but typically range from 150-300°F for 1-2 hours. This hardens the coating fully.

Cerakote bonds exceptionally well to metals, plastics, and other firearm materials. The resulting finish is durable, corrosion resistant, and provides excellent protection in most any environments a firearm may see. Maintenance involves simply cleaning - no need to reapply. With proper prep work and application, Cerakote coatings will last for many years of hard use.

Cerakote Kryptek Camouflage{AR receiver sets finished in Kryptek Camouflage Pattern Cerakote}


Duracoat

Duracoat is one of the most durable and robust firearm finishes on the market. It is a resin based coating that is also applied as a spray and then oven-cured. The durability of Duracoat comes from its resin properties and bonding process.

When applied properly and cured, Duracoat forms an extremely strong bond to the firearm surface. This resin based coating is resistant to scratches, chips, chemicals, solvents, corrosion, and high temperatures. Duracoat has been tested to withstand temperatures exceeding 1,200 degrees Fahrenheit.

The resin-based composition also provides excellent abrasion resistance. It can withstand rubbing, scrapes, and surface wear far better than traditional bluing or paint finishes. Duracoat will not rub off from repeated handling and holstering.

In salt spray and corrosion tests, Duracoat performs exceptionally well. The coating prevents rust and oxidation, even when subjected to salt air and humidity exposure. Firearms finished in Duracoat can be used in harsh conditions and maintain their protective finish.

Duracoat is designed to provide lasting protection and durability for firearm finishes. Its unique properties, bonding process, and resistance to wear, corrosion, chemicals, and heat make it one of the toughest finishes available. Much like Cerakote, Duracoat's durability has made it popular among military, law enforcement, and civilian firearm owners who need a finish that can hold up to rugged, long-term use.

DuraCoat Multicam Camouflage{AR finished in Multicam Camouflage with DuraCoat}


Anodizing

Anodizing is an electrochemical process used for coloring and corrosion protection of aluminum parts on firearms. During the anodizing process, the aluminum surface is converted to an aluminum oxide layer through an electrolytic process. This aluminum oxide layer is very hard, durable and provides excellent corrosion and abrasion resistance.

Anodizing works particularly well for aluminum parts and components due to the reactive nature of aluminum. When exposed to the environment, aluminum readily forms an aluminum oxide layer. However, uncontrolled oxidation results in unsightly discolorations. Anodizing allows this oxidation layer to be carefully controlled and accelerated through electrochemistry.

The anodizing process starts with an acid etching bath to clean the aluminum surface and remove impurities. This is followed by immersion in an electrolytic solution and applying an electric current which accelerates the growth of the oxide layer. By controlling the thickness of this oxide layer, anywhere from 0.0001" to 0.001", the protective qualities can be optimized.

The final step involves applying dyes or pigments. The porosity of the anodized layer acts like a sponge and absorbs these coloring agents. A sealing bath is then used to close the pores and lock in the color. This creates a uniform and durable colored finish.

The hardness and thickness of the anodized layer provides excellent protection from scratches, corrosion and weathering. It also provides good electrical insulation. The dye absorption allows a wide range of color options. Overall anodizing is an ideal finish for aluminum firearms and components when color and protection are desired.

Anodizing Finish{Rare Breed Spartan Lowers Anodized in standard Black finish}


Teflon Coatings

Teflon coatings, sometimes referred to by brand names like NP3 and EXO, provide excellent corrosion resistance and lubricity for firearms. The slippery surface reduces friction and allows the parts to move smoothly. Teflon also repels water and many chemicals.

Pros of Teflon Coatings:

  • Extremely durable and long-lasting finish
  • Provides excellent corrosion resistance
  • Creates an ultra-smooth, slippery surface
  • Repels water, oils, and many chemicals
  • Easy to clean
  • Available in a variety of colors

Cons of Teflon Coatings:

  • Expensive compared to other coatings
  • Surface can be easily scratched or damaged
  • Difficult to apply properly without industrial equipment
  • Limited number of certified applicators due to complexity of the process
  • Provides less overall protection than some coatings

Overall, Teflon coatings offer exceptional lubricity and protection against corrosion. The ultra-smooth finish allows parts to operate smoothly with less friction and fouling. While durable, Teflon coatings can be scratched or damaged, so care must be taken to avoid marring the surface. The application process also requires hazardous chemicals and specialized equipment. For maximal corrosion resistance and protection, other coatings may exceed Teflon. But for smoothness and lubricity, Teflon is hard to beat.  Finishes such as Nickle Teflon are highly effective for use on moving parts such as bolt carriers.

NP3 Nickel Teflon Plating Finish{Nickle Teflon (NP3) plated on a AR port door cover}


Hydrographic Printing: Patterns Galore

Hydrographic printing, also known as water transfer printing, is a method of applying printed designs to three-dimensional objects. It has become a popular finish option for firearms due to the wide variety of patterns and designs it allows.

With hydrographic printing, the pattern possibilities are nearly endless. Anything that can be printed on paper can be applied to a firearm through this process. That means photorealistic images, artistic designs, wood grain effects, and abstract patterns are all possible. The prints utilize high resolution imagery, so even the smallest details come through in the final finish.

Some common hydrographic patterns for firearms include:

  • Camouflage - From classic camo looks to modern digital styles, hydrographic printing can recreate camouflage patterns with precision. Popular options are woodland camo, desert camo, and multicam.
  • Carbon Fiber - The weave and texture of real carbon fiber can be mimicked through hydrographic printing. This gives a firearm a lightweight, high-tech look.
  • Wood Grain - Convincing wood grain finishes like oak, walnut, and maple can be applied for a traditional aesthetic.
  • Marble - Elegant marble patterns containing swirls of color resemble polished stone.
  • Animal Prints - Animal fur patterns like snakeskin, leopard, tiger, and zebra come through in realistic detail.
  • Artistic Designs - Abstract shapes, graffiti art, and other graphics can make for unique prints. Even custom artwork is possible.

The variety of available hydrographic patterns allows for complete customization when it comes to finishing a firearm. Shooters can choose a print that aligns with their style and personality. While hydrographic printing started out as a way to apply camouflage, it has grown into an art form all its own in the firearm world. The pattern options are virtually unlimited.


Conclusion

Firearm finishes serve an important purpose in protecting gun metal from wear, tear, and corrosion while also providing aesthetic customization. There are a variety of finish options to suit different needs and preferences.

  • Bluing and nickel plating are classic metal finishes that provide protection and an attractive look, but require more maintenance and care than modern finishes. Stainless steel has excellent corrosion resistance for a minimalist look.
  • Cerakote and Duracoat offer excellent durability and customization with a wide range of color and pattern options.
  • Anodized finishes provide a very hard surface while adding bold colored accents for Aluminum parts.
  • Teflon-based coatings like NP3 provide effortless lubricity and cleaning.
  • Hydrographic films can create unique camo or graphic patterns.

Proper cleaning and maintenance are essential for any finish to maximize longevity and performance. With proper application and care, any quality finish should provide many years of service.