All guns have metal parts, or are made entirely from metal, and metal can corrode. Sad fact of nature when considering what it can do to our firearms slowly over time. Whether you use your guns the way they were intended or keep them safely ensconced in a cabinet or gun safe, rust is still a pervasive and insidious threat, and one we must perpetually be on the lookout for.
It does not matter if it appears on a gun in complement of a collection of scars, scrapes and other wear from rough times in the field or it magically pops up overnight on a pristine safe-kept specimen, you must deal with it. Left unchecked, unsightly rust can lead to serious damage, even breakage of any firearm.
So if you have a gnarly working gun, blemished showpiece or ragged rescued blaster, this article will give you the knowhow and info you need to smite the red menace.
The Life of Rust
Full disclosure, I am not a metallurgist, and I do not play one on T.V., so this article may be brushing over what are surely fascinating minutiae pertaining to the formation and processes of rust, no doubt to all of the chemists and metal professionals in the audience.
To you, I apologize, but I regret nothing since I will have doubtlessly saved many of us a heap of tedium. This section will serve as a fast overview of what rust is so that we might better understand how to combat it.
Rust forms on metal surfaces in response to the presence of moisture, even trace amounts of water in the air. Water and iron, rather oxygen and iron get frisky and form iron oxide, or commonly, rust.
Compared to other surface reactions on other metals, take for instance the patina that forms on copper, rust offers no protection or other beneficial perks to the metal beneath, instead remaining completely permeable to more air and water, allowing ever more iron to be converted to iron oxide. This conversion process is rusting.
With enough time and neglect, all iron in an object can be converted to iron oxide, quite literally rusting away to nothing. Even a small amount of rust on the surface can leave unsightly pits and blemishes after it has been scoured away; these are little bites taken out of the metal itself, and long the bane of anyone wanting to keep metal pristine and shiny.
While all rust we are concerned with is more or less the same, its appearance and behavior can vary significantly. Most rust appears as a typical red-brown, but some will appear much browner or much redder. It can be faint, even dusty in appearance, or show itself as a big, obvious blemish.
Lesser deposits of rust can be simply wiped off the surface of the afflicted metal but more substantial instances will need serious attention. These latter, larger deposits are more likely formed by some drop of water or perspiration from the body, while “dust rust” is more likely occurring from moisture in the air versus direct contact.
What Causes Rust to Start?
We know what rust is, so what in practical terms causes it to appear, what is the culprit? Well, it depends on a few things that make metal susceptible to rusting or inhibit it. The specific type of metal is a big one, as all metals and alloys are more or less prone to rusting.
The environment is another huge influencer: high humidity, salty air and corrosive atmosphere from smog and chemicals will greatly accelerate rust, all other things equal.
Incidental contact with rust-causing agents is another common culprit, and depending on the agent, one that can be quite severe. Any old-timer who has left a gun in a leather holster that was tanned with chromium salts knows what kind of havoc that will visit on a nice sixgun.
Some poor folks have especially corrosive body chemistry, and in the course of carrying, and perspiring on, their gun, are astounded to see exposed metal parts covered in furry, red rust!
Some people that handle guns regularly without wiping off acidic fingerprints will see the evidence of inscribed in thin rust the next time they pull out the gun.
Guns exposed to any of the above will need through and frequent care to eliminate these contaminants and protect them against ongoing rusting.
The good news is that this care is actually quite simple in any case except one where the gun has been completely immersed in something like salt water, or soaked so thoroughly in sweat that the internals show sign.
Metal Finishes, Rust and You
This preventative anti-rust regimen will need to be performed more or less often based on the finish applied to the metal of the gun. This is another major variable, as some finishes are extraordinarily strong against rusting, while others will blossom red if you breathe on them.
Some metallic finishes are damn near rust-proof, some are fair, and others are poor, or actually encourage rusting. Non-metallic finishes are actually proof against rust so long as they remain intact with no scrapes or gouges reaching the underlying metal.
No matter what the finish is, just like your grandpa told you, it is easier to prevent than fix, and stopping rust before it starts is your mandate.
Knowing how often to wipe down and oil your gun to prevent rust is going to broadly be determined by what kind of finish it has. Guns over the years have been made with, and are still made with all kinds of finishes, so we’ll discuss a few of the most common here below.
Your modern guns, especially handguns, will be finished with either a tough, hardworking finish like nitrocarburizing, have a bare “steel” finish or be coated with a non-metallic finish like Cerakote (which is uniformly excellent). Other finishes exist, or were more prevalent in older days, like classic gun bluing, or Parkerizing.
Your heavy-duty finished, like nitrocarburizing, are usually mentioned with a trade name to make it less of a casserole salad. Glock uses the trade name Tennifer. S&W dubs the coating on their M&P’s Melonite.
H&K calls theirs HEM, for Hostile Environment Finish. These finished are often applied and then overcoated to achieve either a duller or glossier look and coloration, but all are supremely rust resistant among metallic finishes if applied properly and require very, very little care.
These coatings both have an extraordinary and nearly infinite color range, and both offer total resistance to rust so long as the metal beneath is not exposed through the coating from damage or misapplication.
Of these two, Cerakote is superior in every way imaginable, and is amazingly thin while still offering incredible abrasion resistance. Cerakote is also mostly responsible for the wildly varying patterns and colors you see on custom guns today.
A gun that has a “steel” finish is likely made of stainless steel, which as most dads and other handy types know is not stain-free but merely stains-less-often. Depending on the exact type, it will offer good to very good rust resistance, but will need periodic care, especially from salt.
Other bright, shiny metals may be in actuality chrome plating, long legendary for its rust resistance but a bastard to keep mirror shiny, or nickel plating, which is highly corrosion resistant in some situations.
That bluing I mentioned that appears midnight blue to near black and is so beloved (rightly!) by shooters is a highly traditional and sadly very vulnerable finish as far as rusting is concerned.
Fun fact: bluing, and its cousin browning, are actually themselves a form of rust, and both will need regular or even constant care to prevent “real” rust from eating them alive.
Older steel guns that are a hazy, rough gray or charcoal color, and sometimes a greenish color, may be parkerized. This was the O.G. tough finish before the common use of nitrocarburizing above, and is still in use today. Depending on how carefully it was applied, rust resistance is anywhere from okay to good, though you should still be taking care to lube regularly.
No matter what kind of gun you have, and no matter what finish, you probably noticed my mantra throughout the section: “regular care, oil, lube.” That is because regular wipe downs with a clean, oiled cloth is the simplest, best way to prevent rust from forming on any finish.
This is not to say you should not care about or find out precisely what your gun’s finish is because you should, as understanding what your finish is capable of withstanding will help you take better care of your gun.
This is important info should worse come to worst and you have to scour rust off your gun’s surface: you cannot whale away on bluing like you can some other metal finishes, and you must use care when choosing cleaners and so forth, as more aggressive ones might attack the finish itself!
Rust Prevention 101
The easy way: wipe the gun down regularly with a clean, oiled rag and keep them in a dry location with some kind of moisture control solution, desiccant or similar to tame ambient moisture in the air. If you use the gun and it gets wet from any source, dry it thoroughly before lubing it.
If the gun was inundated with water, you’ll have no choice but to have it detail stripped and re-lubed, especially of it was salt water. Some folks have success in that case by using high pressure air to thoroughly blow out the gun, but invariably there is a nook or cranny where water collects, waiting…
Plastic parts obviously do not need to be oiled, but take care that every metal surface, part, control and place on the gun gets a light sheen of oil on it.
If your guns are used in corrosive atmospheres, near salt water of or in very humid environs, or you are one of the unfortunately very sweaty people, you’ll need to increase the frequency of your preventative maintenance regimen, used the gun or not.
Also, take special care in the following situations: keeping the gun in a case or holster of any kind, especially leather as leather traps moisture and may itself leech harmful chemicals or dyes onto the gun and wreak havoc on your finish. As a general rule, if a gun is carried or shot often it should be inspected and treated for rust formation at least once a week.
Getting Rid of Rust
Sometimes it is never enough, and it didn’t make any difference no matter what you tried: you have rust on your gun! Ack! Now is not the time for panic, let’s deal with it as best we can before, and if, we need to call in the cavalry. What we need to be honest about is the severity of the rust.
A badly rusted-through or rust-covered gun, or one that is showing significant deep pitting, is probably in need of a trip to a gun doctor (your gunsmith) to assess, potentially repair and refinish.
You probably lack the skills to assess the structural integrity of the gun! Rust corrodes metal! You cannot assume a severely rusted gun is safe once the rust is removed!
Assuming the rust is not too bad, you can proceed to the next section, our supply list for doing the job right.
You’ll need some specialty supplies, but most handy types and shooters will have most or all of this stuff already. You’ll need either some bore cleaner or gun-specific rust remover
Caution: Ensure the rust remover is safe on your gun’s finish, and wear protective gloves and eyewear as many of them are harsh, a natural cloth rag or old shirt, steel wool in 000 and 0000 grades, and a fine copper brush. Gather all of this then head to your work area. This will get smelly and messy most times, you have been warned.
Start by soaking your rag with your rust remover chemical. Wipe down the rusty area so it is wet, but it does not have to be dripping. Follow the instructions on the package, or give it 5 minutes. Next we will attack our rust deposits with ascending levels of aggression with the intent of removing the rust but saving the finish, if we can.
Start with another clean rag soaked with your rust remover. Rub the rust firmly and see if any is coming off on the rag. That may do it. If not, switch to the copper brush, and taking care to scrub in the direction of the grain in the metal, see if that will take it off. Every so often wipe the area down with the rag and cleaner to check your results.
If that doesn’t work, step up to the 0000 steel wool. Again, go back and forth with the grain of the metal. If that still does not work, switch to the 000 steel wool and repeat. That is starting to reach the end of things you might try, as anything more aggressive, wither brushes or metal wool, has a good chance of mauling your finish.
Some old timers claim to have used a genuine copper penny to remove stubborn deposits because the copper marks left behind are easily removed, but your mileage may vary.
Assuming that the above worked, inspect the pitting, if present, carefully to ensure no rust lurks within. If left behind, rust will return quickly. Once you are all done, wipe the whole area down one more time with a clean rag and cleaner, then wipe dry and re-lube with your favorite gun oil. Whew! You did it.
As a last measure, pay close attention to the condition of the gun’s finish where the rusting was. If the finish was compromised, you’ll need to have it touched up, refinished or otherwise covered unless you want to be dealing with rust more or less constantly at that location. Keep the gun well oiled this time at any rate.
If the gun is for defense, and lacks a modern, heavy-duty finish, you might consider having one applied.
Rusty guns are eyesores but more crucially may suffer impaired function or even breakage if neglected. Even with the best high-tech finishes, rust is always a concern so you should understand how rust works, how to prevent it and how to remove it from your guns. Keep them cleaned, checked and oiled, and you’ll get no issues from rust.