Bluing is a process usually used by gun owners and firearms manufacturers to improve the aesthetic value of their weapons. It provides the steel surface with a layer of protection against rust and corrosion while reducing potential glare as well.
For most of the time, guns that utilize carbon steel components are the prime candidates for bluing but it’s totally possible to blue stainless steel as well. However, there are certain characteristics differences between the materials so knowing clearly how to blue stainless steel is really important.
If you are new to the subject and are in need of detailed instructions, then you’ve come to the right place.
First, let us go through a couple of bluing concepts which you have to know in order to achieve the desired result.
Technically speaking, bluing is more or less a conversion of red iron oxide (Fe2O3) to black iron oxide (Fe3O4). The name of the process actually comes from the blue-black appearance of the black iron oxide.
The steel is also used for producing great police flashlights with awesome durability. There are many methods you can use to blue the steel. These include hot bluing, cold bluing, niter bluing, and so on.
However, due to the unique qualities of stainless steel, you can’t simply blue the material however way you like.
Stainless steel can only tolerate hot bluing and a limited amount of chemicals. So unless you have sufficient equipment and skill, it’s advised to let a professional perform the bluing for you.
High temperatures and dangerous chemicals mean that a moment of carelessness can make you pay a heavy price. The use of stainless steel alloy varies a lot from one manufacturer to the other and that’s why the bluing effect won’t always consistent.
We strongly advise that you only push through with this process if you are absolutely confident that you are able to perform the necessary precautions.
- Necessary Gears and Tools
Necessary Gears and Tools
Safety is the number one priority so protect your body as much as possible. The ideal setup is a pair of long sleeve gloves along with splash goggles and a face mask.
Depending on the manufacturer’s manual, you’ll have to prepare roughly 6 to 8 tanks to perform the bluing effectively and efficiently.
Thermometers and stirring tools are also needed, as well as something to heat up the tanks. Gas burners can usually do the job for this.
An iron wire, stainless dipper, and part basket are required to handle the guns’ components and adjust the bluing solution as well.
For the chemical, the bluing solution should be either Oxynate No. 84 or Du-Lite 3-0. Besides those, you must also have water displacing oil and cleaning solution (Dicro-Clean 909).
Again, don’t mess around with these chemicals and only handle them with extreme attention. Accidental exposure to the chemicals could result in serious injuries. Should something happen, seek medical help right away.
When everything is set up, put on your protective gear and then get down to business.
Step 1: Ready the bluing tank.
Fill the tank with a suitable amount of water then add in the bluing salt using the correct ration. Usually, you can find the manufacturer’s recommended ratio in the product manual.
After that, slowly and steadily stir the tank to dissolve the salt. Be careful since considerable heat might be generated in the process.
When you’re done, attach the thermometer to the tank and fire up the burner. Depending on what solution you use, the tank temperature must be maintained somewhere between 240 and 310 degrees Fahrenheit.
It’s essential to keep stirring the tank to prevent the forming of hot and cold areas. Once the solution reaches its boiling point, turn down the burner to about one-third of the boiling temperature and let it stay there.
Step 2: Process the components of the gun.
Prepare the components of the metal surface before you attempt to blue using your tools. Excessive buffing on stainless steel could result in a grainy appearance so do it with care.
Next, suspend the components in a cleaning solution tank to get rid of dirt, oil, grease, and crud. Keep them in that state while you heat them but be sure to not boil up the tank.An ideal temperature is 180 degrees Fahrenheit but it also depends on the manual.
Wait for 10 – 15 minutes and then take out the components out. Rinse them in a cold water tank after. You can then use a soft brush to gently remove all the residue of the cleaning solution on the components.
Step 3: Suspend the components in the bluing solution tank.
Put all the components into the tank and wait for 5 – 15 minutes. If the solution is still boiling vigorously, then you can expect the bluing to happen naturally.
However, if the bluing effect isn’t satisfactory, then you can try giving the components an acid bath (using Hydrochloric Acid). They should start gassing up in approximately 2 to 3 minutes after exposure.
Then, you can put the components back into the bluing tank and increase the temperature until they turn blue.
Step 4: Rinse the components in a cold water tank then transfer them to a hot one.
Following the treatment in the bluing tank, relocate the components to a cold water tank. Note that it has to be a different tank from the one you used for Step 2.
Let them cool down as you take a closer look at the bluing effect. Make sure to check every nook and cranny of the components so that you can find any discoloration or blemishes.
If everything appears good, then you can transfer the components into a hot water tank. This will remove all the traces of the bluing solution and other chemicals.
Step 5: Submerge the components in a tank filled with water displacing oil.
For the final step, we let the components cool down in water displacing oil. Take them out after a couple minutes and then wipe them clean to remove excess oil. You can reassemble the gun after.
You should note that the blue layer is rather delicate so don’t treat it roughly. Wait for a day to let the bluing properly cure before you to do anything else to it.
And that’s about everything you need to know about stainless steel bluing. It’s a pretty straightforward process.
Though it may seem tricky at first, you’ll be glad to have figured it out because knowing how to blue stainless steel will come handy from time to time.
Now, using the information above, you should have little problem bluing your firearms on your own. Go on and start bluing!
You might also want to read our article on how to darken stainless steel.