Gun Bluing: What Is It & How To Blue A Gun

Gun bluing is a chemical process you apply to steel or iron parts of your weapon to give it a sleek finish and improve its corrosion resistance. From ancient rust prevention techniques to aesthetic marvels, the art of gun bluing has a rich history and diverse methodologies.

You can choose from several gun bluing methods, including hot, cold, rust, niter, and charcoal bluing. Ultimately, bluing your weapon can improve its performance; just make sure you have a gun barrel that is compatible with the particular bluing technique you have chosen!

What Is Gun Bluing?

Gun bluing is a passivation process to protect the gun’s steel against rust. The bluing process involves treating your gun with a solution that converts oxide/rust into black iron oxide.

The process creates a thin protective layer that increases the barrel’s rust resistance and protects against damaging pollutants. Bluing has been performed for centuries by gunsmiths, manufacturers, and gun owners to improve the cosmetic appearance and rust protection of steel gun parts.

Gun Bluing Instructions

What Is The History Of Bluing A Gun?

The history of bluing dates back to when guns were invented. Bluing gun parts served as a way to combat the corrosive effects of black powder residues and atmospheric elements on steel.

Since the inception of bluing, we’ve seen the rise of different methods and techniques of bluing, such as cold bluing and hot bluing.

What Does It Mean To Hot Blue A Gun?

To hot blue a gun means to immerse the gun parts in a boiling solution of potassium nitrate, water, and sodium hydroxide. This process is the most common commercial method today. The hot bluing method results in a deep, lustrous blue-black finish that is exceptionally durable and corrosion-resistant.

How Do You Perform Hot Bluing?

Hot Bluing Gun

The hot bluing method is quite straightforward and involves preparation, bath, heating, cooling, and oiling.

  1. Preparation: Preparation is key when doing the hot method. You must degrease the gun parts and ensure they are free from rust or old bluing. Otherwise, the bluing won’t be as effective as it should be. I use a ball of soft steel wool to do this step.
  2. Bath: Immerse the parts in the hot bluing solution of potassium nitrate, sodium hydroxide, and water.
  3. Heating: Heat the solution to about 275-310°F. Make sure you maintain this temperature.
  4. Cooling: Once the desired finish is attained, rinse parts with water.
  5. Oiling: Apply gun oil to prevent any rust.

Congratulations! You’ve just enhanced your rifle’s corrosion resistance and given it a sleek finish.

What Does It Mean To Cold Blue A Gun?

To cold-blue a weapon, is to apply a chemical solution to the gun, creating a thin layer of black oxide. The cold bluing process is more of a touch-up method. Cold bluing solutions are less durable and corrosion-resistant than hot bluing, but it is much easier to perform and can be done at home.

How Do You Perform Cold Bluing?

Cold bluing firearms are much easier than hot bluing and can be done in five easy steps:

  1. Clean: Like hot bluing, you first must remove all grease and old bluing.
  2. Apply: Next, use a clean cloth or brush to apply the cold bluing solution.
  3. Wait: Be patient and let the solution work for the time specified on the product.
  4. Neutralize: Rinse with water and dry.
  5. Oil: To protect the finish, apply a coat of gun oil.

What Does It Mean To Rust Blue A Gun?

Rust bluing is a traditional technique that involves coating the gun parts in an acid solution. The key is to let the parts rust uniformly and then immerse them in boiling water to convert the red oxide (rust) to black oxide. Rust bluing creates a deep, rich blue-black finish.

How Do You Perform Rust Bluing?

Rust bluing requires five steps:

  1. Clean: Thoroughly degrease the parts you want to rust blue.
  2. Rusting: Apply a solution that promotes rusting – usually an acid solution.
  3. Wait: Be patient and wait for the parts to rust properly – preferably for a day or two.
  4. Boiling: Boil parts in distilled water to convert the rust.
  5. Repeat: This process might need several repetitions to achieve desired results.

What Does It Mean To Niter Blue A Gun?

Nitre bluing is a technique that incorporates bluing salts such as potassium nitrate to create a vibrant blue finish. This method is often performed on small gun parts, such as screws and pins.

How Do You Perform Niter Bluing?

Niter bluing is pretty easy to do and can be performed in four easy steps:

  1. Clean: Ensure no residues remain.
  2. Heat: Heat the niter bluing salts.
  3. Immerse: Dip gun parts into the hot potassium nitrate salts.
  4. Rinse: Quench in water and oil for protection.

What Does It Mean To Charcoal Blue A Gun?

Charcoal bluing is also a traditional gun bluing technique that involves heating the gun parts in a bath of bone charcoal to create a deep blue-black finish. The color produced by this technique is my favorite, as it looks incredibly sleek and premium.

How Do You Perform Charcoal Bluing?

Charcoal bluing is done in three steps, involving the preparatory step, heating step, and cooling step:

  1. Preparation: Clean gun parts thoroughly, ensuring no residue is left. Then, pack the gun parts in a crucible with bone charcoal.
  2. Heat: Heat the crucible to a high temperature.
  3. Cooling: Once your desired coloration is achieved, you can remove the parts are removed and allow them to cool.

Does Bluing A Gun Improve Its Performance?

Bluing a gun improves its durability performance. While it does not directly affect the weapon’s accuracy, bluing adds a layer of rust protection – preserving the life and quality of your gun.

Furthermore, bluing adds an aesthetic appeal, giving you more confidence when shooting. While you don’t feel this is a valid point, it’s important to consider that if you feel confident about your weapon, you’re much more likely to shoot tight groupings. This is one of the main reasons why I often re-blue my weapons, especially my AR-15s. Go test it for yourself and see!

Is It Possible To Re-Blue A Handgun?

It is possible to re-blue your handgun. You’ll first need to strip the old finish before applying your chosen bluing method. Re-bluing is great for restoring older firearms or repairing cosmetic damages.

Can All Types Of Gun Barrels Be Blued?

You can blue all types of gun barrels, but it isn’t advised as the incorrect method on a certain type of metal can damage the metal’s physical and chemical qualities. Blueing is excellent for barrels made of steel and iron, such as AR-15 barrels, but aluminum cannot be blued using traditional methods.

Furthermore, hot or cold-bluing vintage guns can negatively affect the firearm’s value. Also, hot bluing can damage guns with silver-soldered components.

Frequently Asked Questions

What Types Of Guns Can Be Blued?

From rifles to handguns, most types of guns can be blued, especially those made of steel and iron. Those with aluminum or silver-soldered components should be handled carefully, and a gunsmith should be consulted before attempting any bluing process on these types of guns.

Is Bluing A Gun Different Than Painting A Gun?

Yes, bluing a gun is different than painting a gun. Bluing is a chemical process that alters the surface of the metal, while painting is a topical application - adding a layer to your weapon.

The Bottom Line

From experience, I can tell you that bluing is both an art and a science, preserving firearms while showcasing their elegance. You might not get it right the first time, but no worries, few people do. Simply restart all the steps and improve where you think you might have made an error. Whether you’re a gun enthusiast or a history buff, gun bluing offers a fascinating dive into craft and chemistry – permanently altering your weapon’s appearance for the better!

About the author

Charles Neser

I'm a life long hunter & gun lover. Currently pursuing my Master's Degree (M.Sc.) in Animal Nutrition at University of the Free State.

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