How to lubricate your spring-piston airgun
by B.B. Pelletier
Today’s report is a guest blog from our favorite Russian reader, duskwight. Some of you know that he’s fabricating a dual-opposed recoilless piston air rifle for himself that will function similar to a Whiscombe. He jokingly calls it the duskcombe.
If you’d like to write a guest post for this blog, please email us.
Take it away, duskwight!
Oiling and greasing your springer
This report only concerns springers and is meant for those who perform their own service. This is a collection of things taught to me by other very experienced airgunners, and things I learned from my own experience with springers.
Every springer is an air-compressing mechanism made mostly of steel. This is the key that defines everything about your springer’s need for lubrication. So, there are three areas to be addressed:
1. Your springer must be airtight everywhere except for the barrel channel.
2. Your springer works under a significant amount of load and its parts are prone to mechanical abrasion.
3. Your springer is made of a metal that’s prone to corrosion if it contacts water, acids or humidity.
Proper lubrication will address all of these concerns.
Zen monks say, “Forget what you have learned and learn again.” To lube your springer correctly, you need to remove all the grease first, especially if your gun is new.
Airgun makers prefer to be on the safe side and usually put lots of grease on guns to make their products corrosion-proof for storage. Sometimes, they think that their customers are a bit irresponsible and will never again service their springers. This holds true for every airgun maker – IZH, Gamo, Air Arms, RWS/Diana rifles, as well as the makers of Chinese and Turkish guns.
But the simple truth of this is that no matter why they do it, you need to correct it. Be your own gunsmith. I also noticed that production means reduction, or simplifying things. Makers prefer to cut their expenses even on grease, so they use the same cheap grease for the whole rifle. Not only is that wrong, but it’s also where you can gain the advantage by doing it right.
Things you’re going to need
Tools to disassemble/assemble your airgun.
A cleaning rod, a set of brushes, and cotton wads or patches.
A wooden stick — 1/2-inch thick 1-1/2 feet long, or something similar that’s not made of steel.
Lots of cloth (cotton is the best, nylon is the worst).
Solvent: Here you must be careful to not use anything that will dissolve the synthetic seals in your springer. Many modern gun solvents are made expressly for synthetics because of the proliferation of synthetic gun parts these days, so take some time to acquire a safe solvent.
[Editor’s note: The next step involves disassembly of your airgun. Do not attempt this unless you know what you are doing. Disassembly can be dangerous and can also void any warranty on your airgun, so know what you are doing before taking this step.]
What comes next?
Time to disassemble your rifle. I hope you know what to do and how to do this, and remember that springs are springy and steel is a bit harder than the flesh. Here’s a tip: Place all the parts on the same surface in the order that you have removed them. That will ease the assembly process.
Inspect every part. In most cases, you’ll see a thick cover of grease or a thick film of oil on each of them. That’s when the cloth comes in. Wipe every part. Do not try to wipe it dry, just wipe it. That will leave the right amount of oil on the surface and in the pores of the metal. That’s more than enough lubrication. You’ll probably see an oily shine on the surface of the metal parts.
Pay special attention to the trigger assembly. Sometimes, manufacturers fill it with grease. That’s not proper. Wipe all the parts, and what’s left would be enough for a very long time. Some users just dump it into acetone assembled. Well, that’s also a solution, but then you have the problem of lubricating it properly afterward.
A price on Mr. Diesel’s head
The piston and compression chamber that the piston rides in are a completely different matter. They must be as close to greaseless as possible.
You probably know the German surname Diesel — that’s the guy who invented piston engines where the fuel/air mixture ignites when pressure goes very high. It’s the simple physics of the fuel/air mixture igniting from the heat of compression. The diesel effect is good under your car’s hood, but not inside your rifle. Oil fumes and dispersed oil are an excellent fuel for dieseling. All it brings is trouble — burnt seals; deafening sound; overstressed and broken springs, mounts and sights; even damaged barrels, not to mention lots of smoke, bad smell and soot. In short, diesel is a killer.
[Editor’s note: By dieseling, I believe the author refers to detonation, which certainly does all the bad things he says. All spring-piston airguns that shoot over about 600 f.p.s. will diesel to a certain extent; but if you aren’t hearing any explosions and see only a little smoke, the diesel effect won’t destroy your gun.]
Take the piston and remove the seal. Space between the piston head (“mushroom”) and the seal is an excellent reservoir for oil. And the most common place where this nasty guy diesel lives. You’ll probably see that seal’s surface is covered with grey/black oily residue. This is due to your rifle being dry-fired or test-fired at the factory. Check the seal. It must not be cut or melted. If it is, install a new one and take care of all the edges around its circumference. A very fine file or scraper will remove any burrs or extra material.
Take a fresh piece of cloth and thoroughly wipe the piston and the seal with solvent to dry it. If the seal material allows it, wipe it with a cloth wetted with solvent. Then wipe the piston. I prefer acetone; it dries very quickly and leaves no spots.
Now for some inside work. Take a long wooden stick and wrap some cloth on its end. You can use your cleaning rod, but a stick is less prone to bending. Apply a few drops of solvent and use it to clean the inside of the cylinder. The compression chamber must be dry metal — oil and grease have no place inside (for now).
And some finishing touches if you have a rifle with a fixed barrel that cannot be removed. If you’ve got a cleaning rod long enough, use it to clean the barrel by accessing it through the cylinder. Some manufacturers put grease into the barrel, some sort of technical petroleum jelly most times. The barrel also deserves a solvent wash, as the diesel effect can happen inside the barrel, as well.
Alright, the gun is clean. Now we’re ready to lube.
Dos and don’ts of lubricating
Use petroleum-based oils and greases for this lubrication. Do not use silicone-based lubricants for metal parts. Silicone-based lubes are for plastic parts that have low levels of load. Steel lubricated with silicone allows a hard steel part to eat into a softer steel part.
There are also reports that silicone-based lubes can decompose inside the compression chamber and give you a fine SiO2 (silicon dioxide) on the inside walls. SiO2 is basically sand. I don’t know if these reports are credible, but I prefer to stay on the safe side.
Do not listen to the hype about “Teflon coating” or “liquid Teflon” or “contains Teflon.” From a chemist’s and physicist’s point of view, they’re nearly worthless. Stick to tested lubricants, and you’ll be okay.
Do not use organic (vegetable- or animal fat-based) lubes. They tend to decompose and produce weak acids.
Placing the lubricant
Things you’ll need:
Cloth (cotton is the best, nylon is the worst).
Toothpicks to apply the lubricant. I use small flat screwdrivers; they work like little shovels .
A cleaning rod and set of brushes and patches.
Three different types of lubricant are all you need to keep your springer going.
First, some oil for the seal and piston. By “some,” I mean a single drop. I would say that full synthetic motor oil (the real stuff now, not just petroleum that has synthetic oil added) is the best among those most easily available. A quart will last for tens of thousands of jobs. Take an assembled piston. Put one drop of full synthetic motor oil on your fingertip and just rub it over the seal and piston front. That will do the job for years.
Now install the piston in the cylinder. If your rifle is properly tuned, it might give a very light diesel with very light white smoke on the first one or two test shots but no more. Always load the gun for test shots and shoot it into a pellet trap. It’s very convenient to store and apply this kind of oil in a single-use syringe.
Let’s use something for the mechanical parts. This is the second type of lubricant we’ll be using. I’d say the best for this purpose is oil jellified with lithium salts. I’m not sure if there are the same markings and names in the U.S., so let’s describe it. It’s somewhere between jelly and soft butter spread, yellow-orange semi-transparent, with a distinctive petroleum smell. In case it’s doped with MoS2 (molybdenum disulfide), it’s often deep blue with a greenish hue. MoS2 is great, as it reduces friction but simple lithium jelly is more than enough to maintain your rifle. Use it wherever friction occurs. Apply a thin (very thin!) coat onto any joints (cocking lever assembly, barrel joint, etc.) rails and cogs (Whiscombe and IZH-60/61 rifles).
[Editor’s note. In the U.S., we have white lithium grease, which the U.S. Army recommended for lubricating guns like the M1 Garand. It has many automotive applications, where there’s heavy metal-to-metal contact and wear, so I think this will serve the author’s intended purpose. There’s also red lithium grease and general-purpose lithium grease. I would go with the white lithium grease for this purpose.]
I’m not among those who cover mainsprings with heavy tar-like grease. This substance is an invitation to Mr. Diesel, as well as a dust trap. A good plastic (e.g., Coke bottle side) piston shim to reduce the space between the piston and mainspring and a properly fitted spring guide will kill the twang, and wiping the spring with a lithium grease cloth is more than enough.
You can now finish assembling your gun. Check if everything is correct and check for 2-3 “spare” parts on your table. Test how it cocks and then make some test shots…of course, no dry-firing. Your airgun now works as it should, plus all the internal parts are lubricated with the correct substances.
But what about the third type of lubricant? What’s that used for? That’s easy. The third type is the preservative oil you’ll use to clean and wipe your beauty after you use it. I like using How often should I lubricate?
You should not lubricate your springer very often. It mostly depends on how you use your rifle. Hunters and outdoorsmen must clean and lube their rifles more often than backyard shooters. Pistons and seals should be lubed only once in 4-5 thousand shots, together with mainspring maintenance.
[Editor’s final comment. Duskwight wrote a much longer report than what you see here. I condensed it and removed references to certain things that are not accepted in the U.S., such as using gasoline for cleaning parts. I also removed a couple references to types of materials that our readers probably are not familiar with.
Bear in mind that duskwight is in the middle of building a recoilless dual-opposed spring-piston air rifle that will work on the same principle as the Whiscombe, but will be entirely different in design. He’s contracting for each part to be made to his specifications — so this man is light-years ahead of most of us when it comes to spring-piston airguns. He’s also writing from the viewpoint of a different country, and he isn’t even writing in his native tongue!
I don’t know about you, but I learned something in today’s report. The bit about using pure synthetic automotive oil as a piston seal lube was brand new to me. I think we owe duskwight our thanks for sharing his experience with us.]