How To BLUE A Gun Or Gun Parts? [3 Ways For Rebluing]

How To BLUE A Gun Or Gun Parts? [3 Ways For Rebluing]

Though not commonly discussed, rebluing a gun is an important process for maintaining your firearm’s look and utility.

By rebluing your weapon, you can ensure that it maintains a superior look and feel without sacrificing functionality or safety.

While rebluing can be done professionally, and perhaps should be for some more expensive guns, you can reblue your weapon at home.

Doing so will take a thorough understanding of the rebluing process so that you remain safe and do a good job.

In this guide, we’ll go over everything you need to know about rebluing your gun, giving you the tools you need to get your gun back in tip-top shape.

Let’s dive right in!

What Is Gun Bluing?

Bluing or black oxidizing is basically a way of treating the steel through which it creates a thin protective shell type of layer around it.

The method used works by converting the red iron oxide (or rust, Fe2O3) into the black iron oxide (Fe3O4).

The name of the process “bluing” is given due to the blue-black look that is achieved as a result.

The process of bluing a metal can be used on any kind of sheet metal. However, it is particularly more common for gun barrels and other components of the different types of firearms.


Why Do You Reblue A Gun?

Let’s start off with an important question: why exactly should you reblue a gun? Is it really that important?

The truth of the matter is that it’s up to you.

When you bought your gun, it came with a thin coat of iron oxide; this chemical gave your gun that sleek, professional feel and look that likely attracted your attention.

Over time, however, this coating can fade, which ultimately leads to gun rust. Without rebluing your firearm, you’ll find that it begins to lose its luster and can rust in a hurry.

Instead of buying a new firearm, which can be expensive, you can always reblue your gun instead.

This also helps you restore guns that have sentimental value.

Let’s face it: there’s nothing quite like your favorite gun—even a fancy new one.

For this reason, understanding how to reblue your gun will allow you to keep your guns longer. This is perfect for individuals who don’t wish to give up their guns due to strong attachment.

Of course, you may also plan on maintaining your gun’s monetary value.

Here’s the deal: if you let your gun rust without taking action to correct it, it will lose its value—and a lot of it.

As such, you’ll want to be sure that you are doing everything you can to take care of your gun’s appearance.

By rebluing your gun, you can help prevent gun rust that will ultimately make it harder to maintain your gun’s value down the road.

Another important reason you’ll want to reblue your firearm (perhaps the most important one of all) is that you want to make sure that you are retaining your gun’s functionality.

The truth of the matter is that it’s not quite as easy to handle your weapon when it’s rusted and potentially doesn’t fire right.

Knowing this, you’ll want to do what’s necessary to make sure that your gun is working optimally at all times.

This is crucial to your safety and the safety of all who happen to handle your weapon.

Knowing all of this, we’ll take an in-depth look at the three best ways to reblue your gun in the next section!

3 Ways To Reblue A Gun or Gun Parts

Rebluing a gun can be easier than you think.

Below, we’ll go over the three most common ways firearm owners reblue their weapons to help secure firearm longevity and aesthetics.

1- Cold Bluing

Let’s start with the simplest of all bluing techniques.

If your gun has only just started to lose its bluing, you’ll find that the easiest and most appropriate way to correct the problem is by using a cold bluing kit.

These kits are designed for guns that do not have extensive damage to the existing bluing.

Because they are designed for guns with minimal damage, these gun bluing kits are also the cheapest of the three options we’ll discuss.

Keep in mind, however, that they are also the least durable, meaning you may find yourself having to repeat the process sooner than if you had chosen the other two options.

So what is cold bluing?

It’s actually simpler than you may think. Let’s go over the proper method, step-by-step, so you can make sure you get it right the first time.

  1. Remove Old Bluing (Optional)

You’ll want to start by judging the state of your bluing. If you think it’s too damaged, you may decide to go ahead and remove it entirely.

For many cold bluing projects, however, you’ll likely find that the majority of your bluing will remain intact.

To remove your bluing, you’ll want to use specific chemicals, such as Naval Jelly (which is actually an automotive rust remover made from a phosphoric acid).

Or you can use white vinegar, which possesses acetic acid that will naturally remove your bluing.

  1. Polish Gun Metal

Using either 600 to 1200-grit sandpaper or 000 steel wool, gently polish the gun metal to remove any blemishes, scratches, or rust.

This will help to give your gun back its natural shine.

  1. Clean the Metal

If you’re simply looking to enhance your current bluing, simply apply cleaning oil to the locations you wish to blue.

This will help to remove the old bluing completely. When you are done, go over the spots with acetone to make sure you remove all of the cleaning solutions.

If you wish to clean the entire gun, however, you’ll find it easier to simply put the entire gun into a cleaning solution. Consider using sodium triphosphate or denatured alcohol.

  1. Heat the Metal

Heating the metal before applying the bluing solution can help the gun soak in the material better and keep it longer.

For this reason, consider leaving your gun out in the sun for several hours, heating it with a heat gun, or using a blow dryer to prep the gun for bluing.

  1. Apply the Solution

Using a clean applicator, begin to gently apply the solution to the area you wish to be blued.

Instead of applying it broadly over large areas, make sure to apply it in a single swipe and then use a piece of steel wool to even it out.

This will keep your coat smooth and polished looking.

Make sure to keep these tips in mind: use a cotton T-shirt for large area applications and a cotton ball or swab for smaller areas.

Additionally, remember that you can soak screws and other hard-to-blue items in the solution.

Do not simply apply the bluing solution once. For a proper finish, you’ll likely need to apply it around seven times, using a new piece of steel wool to smooth out every new layer.

You want to end up with a dark-blue finish. If you do not, you may find you have to go back to the beginning to sand out any rough patches in your gun.

  1. Top with Gun Oil

To finish, apply a coat of gun oil and then wait for a few hours. Then, using a cotton ball, remove the oil and apply again.

Repeat the process every few hours to provide your gun with the ultimate finish.

If you are wondering what works better between – painting a gun and cold bluing – let me tell you that cold bluing method is generally much better than epoxy-based special spray paints.

However, if you are looking to save a few bucks then painting can be a good alternative.

2- Hot Bluing

When compared to cold bluing, hot bluing involves a bit more patience—and tougher work.

Despite this, you’ll find that it works better for guns that have lost significant amounts of their bluing.

What’s more, guns that are treated with the hot bluing process tend to hold up longer, so you’ll definitely want to consider giving this a shot depending on the state off your firearm.

  1. Polish Bluing Location

Using the same sandpaper or steel wool you would use for cold bluing, begin by polishing every location you wish to blue.

  1. Prepare Gun for Dipping

Doing this step correctly will help you later when you clean your gun and apply the bluing solution.

Start by threading a soft wire through the barrel of your gun and putting the small parts of your gun into a wire basket.

This will substantially simplify later steps when you need to dip your parts into the bluing solution.

Later, when you move your parts from the cleaning solution to your bluing solution, you’ll thank yourself for going ahead and getting your parts prepared.

  1. Dip into Cleaning Solution

Using an appropriate solution (like any of the ones described in the cold bluing section), dip your gun into the tank and immerse it for a full ten to fifteen minutes.

As it is submerged, you want to be sure that you are wiping it so that you remove any impurities and give it a fine polish.

  1. Rinse with Cold Water

Once you are done with this, rinse off for two to three minutes in cold water.

Keep in mind that if you used dishwasher detergent to rid the gun of cleaning solution, hot water is the preferred rinsing solution.

  1. Dip into Bluing Solution

You’ll want to start by stirring your bluing solution.

Using Traditional Caustic Black, give the solution a solid stir to break up any salt clumps and other tough areas in the solution.

Then, you’ll want to heat it to a temperature between 275 to 311 degrees Fahrenheit.

Once you have done this, you’ll want to dip two parts: your gun barrel that you’ve wired and the basket of parts.

Be sure to dip your barrel in at an angle to let all the air escape from it. You’ll also want to move your basket around in the solution to be sure that your parts are completely covered in solution.

You can leave your parts in the solution between fifteen or thirty minutes. Be sure to check appropriately to tell when your gun has the right amount of blue hue.

Importantly, make sure that you do not put your gun’s stainless steel parts into the bluing solution.

These should go into a separate mixture of heating chromates and nitrates.

When you are satisfied with your bluing, remove the gun parts and rinse them off thoroughly in cold water.

  1. Boil Gun Parts

To remove the remainder of the bluing solution, boil your gun parts in hot water.

Consider boiling smaller parts for five to ten minutes and more complex parts for up to thirty minutes.

  1. Place in Oil

As the final step, you’ll want to place your gun parts into a solution of water-displacing oil.

This solution will help cool the parts off and protect them from external elements such as sweat, rust, and body oil.

Leave in the solution between forty-five to sixty minutes.

3- Rust Bluing

Rust bluing is a simple bluing technique that will have your gun looking as good as new. Let’s take a look at how this technique is performed in the steps below.

  1. Polish Bluing Location

Using the same sandpaper or steel wool as you would for the other techniques, polish all bluing locations so that they are free from impurities.

  1. Clean Chemically

Clean off any excess dirt or grease with one of the aforementioned cleaners brought up in the cold bluing section.

Before doing so, check with the manufacturer to make sure that the solution is appropriate for your particular rust bluing solution.

  1. Coat with Bluing Solution

Open your acid bluing solution and leave it in a closed cabinet with your gun parts for twelve hours.

Make sure the cabinet is sealed. During this time, your weapon will soak up the fumes and blue naturally.

  1. Boil in Distilled Water

Once done, boil your gun parts in distilled water to halt the rusting process instigated by the acid solution.

  1. Remove Red Oxide

Using a carding brush, gently remove the red oxide that has formed on top of the weapon.

Underneath will be a coat of fine black oxide. Repeat the process (starting with the acid fume bluing) as many times as desired so that you get the level of finish you are looking for.

  1. Coat with Oil

After this, coat your gun parts with oil. This will protect it from rust and other unwanted elements.

Allow the oil to stay overnight before you put your gun back together.

Which Gun Bluing Method To Use?

  • Perform hot bluing process if you want to get the longest-lasting metal coloring effects
  • Perform rust and fume bluing process in order to achieve the best protection from the rust


While working with any of the bluing processes, make sure that you do it in a well-ventilated area.

Especially when performing hot bluing process care that you stay protected from the noxious caustic salts that are being used in the process.

What Products Should You Use for Bluing?

Usually, I make use of Birchwood Casey Perma Blue Liquid for bluing my firearm barrels (available on Amazon HERE).

It works fine for me and I believe that it’s a proven way to remove the less stubborn scratches and worn spots on rifles, shotguns, pistols, axes, and even other household items like a steel knife.

If you are seeking a quick touch-up or to completely re-blue your favorite shotgun it may work excellently.

Well, in case you do not like Birchwood Blue Liquid, you can use any other bluing solution.

For instance, there is a “Du-Lite” solution which is often good for professionals and manufacturers such as Colt or Smith and Wesson.

Whatever product you use, just make sure that you do not get that on the inside of the barrel, especially when hot bluing.

As a prevention, you can consider plugging the ends of the barrel which will ensure that no solution gets inside.

Can Bluing Remove Fingerprints On The Barrel?

In most cases, Birchwood Casey’s cold bluing kit can work great in removing all types of scratches, stains and even fingerprints that are hard to remove.

But in case if the fingerprint is etched completely into the body it may be hard to get them removed.

In case you do not find these solutions useful, you can try other alternative methods like wiping it using a ball of super fine steel wool soaked with some lubricant or oil substitutes like WD-40.

Even if it may not remove the fingerprints completely, it can work to make them less noticeable. Also, it will avoid them from reappearing back after some time.

Few Warnings and Tips when Bluing Your Rifles and Guns

While rebluing is a great way to bring extra shine and luster on your firearms, you need to be extra cautious while performing the process (the scientific term “passivation”) in order to achieve the desired results without getting any damage to parts like wooden stock.

Below are a few warning tips you may need to know;

  • Before starting with the process, make sure that the gun you are bluing is unloaded
  • If possible, remove the stock and gun handle from your gun
  • Do not work the hot bluing method on aluminum. It can react and can be dangerous

In addition to above also, avoid the hot bluing on old double-barreled shotguns or your vintage shotguns, particularly the ones that come with any kind of soldering or are brazed with silver solder.

The Bottom Line

With the information contained in this guide, you’ll be able to get your firearm reblued in no time.

If you’ve got a weapon you wish to firearm, follow these steps carefully to make sure you get the job done right.

In the end, you should wind up with a weapon that looks better than ever!

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