Ultrasonic Cleaners

#1
I don't consider myself an expert on anything, but I will give my $.02 worth. I am viewing it from an Armorer / Gunsmith level. If you haven't had a good Armorer Course on each weapon system you use, then I would suggest seeking one out. Knowing how a gun runs, how to give it a thorough break down and cleaning, troubleshoot and repair it, is very important, especially when lives depend upon it as it has to run 100% in all field conditions.

When teaching Armorer Courses, this discussion usually comes up of what are my thoughts on Ultrasonic cleaners.

First, I will say that they work. Second, I will say that if you use them wrong, you are possibly creating issues. Third, I will say that if you use them correctly, then they can be a great asset.

I see many Law Enforcement Agencies that get them, tend to treat them as a dishwasher, where they just want to throw the gun in the cleaning tank, walk away, come back 20-minutes later and pull the gun out, and out the gun back into service. This is NOT GOOD, and you are creating issues, which could be major if the gun doesn't work when it needs to (Reliability), and you can also create problems of longevity of parts. Think of it like this, if you take dirty dishes from the dinner table and throw them into the dishwasher, run it, then upon removing the supposed clean dishes from the washer, how many of them are actually clean, and how many of them still have food remnants stuck to them?

If you put a complete firearm, or sub assemblies into the ultrasonic tank, then it will clean, but how do you get the fouling out of the assembled parts. An example would be if you field stripped a Glock into an assembled frame, assembled slide, barrel, action spring, and inserted them into the ultrasonic tank, and ran it through a cleaning cycle. The cleaning cycle would remove the fouling, but how do you get the fouling and cleaning solvent out of the assembled parts (ie: Slide assembly that has the firing pin assembly, extractor assembly)? Then you also have liquid solvent inside the firing pin and extractor assembly, where fluids are not supposed to be as it is meant to run dry.

For a shotgun like a Remington 870, Mossberg 500/590, Benelli, Winchester etc, if you drop the entire shotgun into the tank, it will clean, but how to do you get the crud out of the gun. If you pull the barrel off, it would clean the barrel. But it you through the assembled receiver, it would clean, but how do you get the crud out of the bolt assembly, trigger group assembly, or stock assembly.

If you were to drop an AR15 upper receiver assembly (Upper receiver, barrel, gas tube, gas block/front sight base, barrel nut assembly, front & rear sight assemblies, forward assist, ejection port cover assembly, into the ultrasonic tank and run it through a cleaning cycle. It would most likely loosen the fouling. But how do you get the fouling and solvent out of the gas tube, gas block/front sight base, gas port, barrel, underneath the barrel on the threads, etc? The same thing is true on other guns like Piston AR15's, M14/M1A, M1 Garands, Mini-14s, Remington 1100/1187, etc.

Then once the ultrasonic cleaning cycle and solvent as cleaned everything, all the lubricant has been removed from the pores in the metal, leaving it bone dry, and that lubricant is there to protect it from corrosion (rust), and reduce friction. The usual answer to this is to simply drop the gun or assemblies into a lube tank, which by dunking everything into a lube tank it allows the lube to go back inside the gun and lubricate everything that needs it. In reality the lube tank will allow all parts that lube can flow into and onto get lubed, but what about sub assemblies that are threaded like the barrel nut threads, sight parts (threads, pins, springs, ball bearings, detents, etc. Also you are then introducing lube into areas that are meant to run dry (Gas port, gas tube, gas block/front sight base).

The lube bath on a handgun like a Glock, would allow lube to get into areas like the firing pin assembly, extractor assembly, where it is designed to run bone dry. If you get lube into the internal parts of a slide assembly on guns like Glocks, it will cause issues.

Now for the best way (IMHO) on how to use an ultrasonic cleaner, is to disassemble the entire firearm into small parts parts, like a Glock breaks down into 30-something parts depending upon model and generation, and then if you want to ultrasonic clean it, you will get all the parts clean. Then inspect all the parts as you reassemble, making sure all fouling is removed, inspect for erosion and stress (replace parts when necessary), then reassemble the parts dry that are meant to run dry, and lube the parts that need to be lubed.

If ultrasonic cleaning an gas gun like that AR15 system (Gas impingement or piston) then you can disassemble the lower receiver into parts. This would mean removing the trigger system, bolt catch, magazine catch, front pivot pin, rear takedown pin, stock assembly, grip and safety assembly, then clean the lower receiver. Once clean, then reassemble the parts, making sure to lube all the springs, detents, detent tracks of the safety selector and takedown/pivot pins, threads of the grip screw and stock assembly, buffer retaining detent spring & detent, etc. I would not recommend or suggest cleaning the upper receiver assembly of an AR15 in a ultrasonic tank, as you are introducing solvents & lubes into the gas system, where you cannot get the loosened fouling out, and you should not put lube into, as it will cause problems.

II know an Officer who treated his Agency's ultrasonic tank as a dishwasher, and dropped an assembled M16 rifle, complete with Leupold CQT optic on top, into an ultrasonic tank, and left it there overnight. It did get things clean, left everying bone dry, destroyed the optic, and all the assembly parts in the gun still had the loosened fouling stuck under them, and all hidden parts (threads, springs, detents, etc) were bone dry and had no lube to reduce friction or protect from corrosion. This Officer was treating the ultrasonic tank as a dishwasher.

IMHO the best way to clean an AR15 upper receiver is to scrub the receiver with a tooth brush and solvent, then rinse or wipe the loosened fouling out. Clean the inside of the barrel, which includes the chamber, bore, and lug recess where the bolt locks into battery. Cleaning the chamber and lug recess is done with a chamber brush and solvent. Cleaning a bore should be done using a bore guide, bore brush, cleaning rod, solvent, jag with patches, and I like to use denatured alcohol as a rinse to remove the cleaning solvent. Then when necessary to remove copper fouling, I recommend using a copper solvent with a jag, cleaning patches, and follow up with denatured alcohol to remove any copper solvent. Imho, NEVER PUT ANYTHING INTO THE GAS TUBE, this includes solvents, pipe cleaners, cotton swabs, etc, as there is about 14,000-PSI gas pressure that goes through the gas tube, which basically keeps it as self cleaning, and any introduction of solvents/lube into this area is going to cause issues, and it makes no sense to be squirting solvent or using pipe cleaners to push things from the back end of the gas tube towards the gas block/front sight base and gas port (In the opposite direction as gas flows). In Armorer Courses we show several examples of plugged gas systems, and when lives depend upon that firearm running 100% it cannot be plugged, so don't do things that would cause it to get plugged.

For cleaning shotguns, break the down into a barrel, bolt assembly, trigger group removed from the receiver), and you can scrub and clean these easily enough by hand. Making sure that you use a chamber brush and bore brush on the barrel (Yes a shotgun has a chamber, and they make chamber brushes for them). Remove the magazine spring and follower, then scrub the inside of the magazine tube using a magazine tube brush (yes they make a magazine tube brush). If a bolt assembly can be field stripped (like a Benelli, Beretta, Franchi), do so, or in bolts like the Remington 870, Mossberg 500/590, then it is open and loose enough to scrub and flush fouling out, but at Armorer Level it should be broken down into small parts and cleaned/inspected then lubed where needed. Trigger groups can be scubbed and flushed at user level, where at Armorer Level they should be disassembled where necessary, cleaned & inspected, then lubed and reassembled. Receiver can be scrubbed with a tooth brush and solvent. Don't submerge stocks into a solvent tank, as you don't want wood soaking up solvents, and you don't want hollow areas inside wood or synthetic stocks filling up with fluids.

Do we have ultrasonic and solvent tanks in our workshop, the answer is yes. Do we use them, yes. But how we use them is to clean small parts. We do not use them to clean assembled parts, and we do not ever use them inside of guns where there are gas systems. I much prefer to scrub things by hand, especially looking at it from an Armorer or Gunsmith level of being able to remove fouling, inspect parts, and properly lube with the proper lubricants where it needs it (Keeping in mind that we lubricant for several different reasons, to protect from corrosion (rust), to reduce friction, and we also lube where we have different types of metals touching each other where we need to protect from electrolysis (Shotgun choke tubes, AR15 barrel nuts, etc).


CY6
Greg Sullivan "Sully"
SLR15 Rifles
TheDefensiveEdge.com
(763) 712-0123
 
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PoisonJelly

Newbie
Network Support I
#2
Thank you very much for the info, I have a question regarding the AR15.
For us who are in the military as the gear is issued, it does not receive the love it deserves, people just clean the "visible surface" for the inspection and don't bother with the deep nooks and crannies.
Would utilizing small-sized ultrasonic cleaners to put the bolt group in for the cleaning make sense?
Or the bolt should be taken apart, part by part and then has to go in?
of course, lubrication after the cycle and before reassembling into the gun is given.
 
#3
Would utilizing small-sized ultrasonic cleaners to put the bolt group in for the cleaning make sense?
Or the bolt should be taken apart, part by part and then has to go in?
of course, lubrication after the cycle and before reassembling into the gun is given.
Ultrasonic cleaning of the bolt carrier assembly, isn't probably going to hurt anything, and will loosen the fouling. But the loosened fouling probably isn't going to find its way out of the ejector assembly. A lubricant tank bath of the bolt carrier assembly is probably going to put lubricant in places that it is needed, and in turn NOT put lubricant in places it needs to be. Lubricant isn't probably going to find its way into the ejector assembly, as this assembly really needs to be removed, cleaned (You will often times find heavy fouling & brass shavings in this area), inspected, spring replaced when needed, and then lubricated. Then the lubricant tank may put lube inside the firing pin channel of the bolt, and inside of the bolt carrier key (gas key) where we generally run these dry.

Keep in mind that the wrong lubricant can cause issues. Issues of gumming things up, or a lubricant that freezes in colder weather will cause major issues. I am in Minnesota, where we are cold about 5-6 months of the year, usually the coldest in the nation, and I have seen guns fail due to the wrong lube. I have discussed this in other threads, but my recommended go to lube for all around is Slip2000 "EWL" Extreme Weapons Lube, which I have personally used in -37F field conditions with 100% weapons reliability, and it works well in heat of the dry desert conditions of summer in Arizona and the hot humid conditions of summer in San Antonio. All lubricants work well until they evaporate or burn off due to heat, that's where I have found that the Slip2000 "EWL", as we have seen this numerous times running rifle instructor & full auto instructor schools in the heat where the guns were ran for 2k-3k rounds over a week in extremely hot weather, and never had to relube.

A bolt carrier assembly can easily be field stripped by removing the firing pin retaining pin & firing pin. Then remove the cam pin by rotating it 90-degrees either direction so it clears the bolt carrier key (gas key), and remove the bolt by gently pulling and rotating it out of the bolt carrier.

Clean the firing pin all over with solvent & brush. The firing pin looks like a double headed nail of sorts, looking at the face of the front head of the firing pin inspecting for a carbon build up that looks like a ring. Scrape this ring of carbon off. Most firing pins are chrome plated, though we are seeing a few nitride treated ones, in either case these are okay to run dry, as the chrome or nitride is slippery enough to help protect from friction, and these treatments also help protect from corrosion. A lube in the firing pin channel can cause things to gum up or freezes, either of which can result in a fail to fire.

Clean the tail of the bolt, removing the heavy carbon build up, and scrub the entire bolt body and lugs to remove any fouling. Scrub the bolt face to remove fouling, and brass shavings.

Remove the extractor assembly by compressing inward on the back of the extractor to take some pressure off the extractor spring, while at the same time use the firing pin retaining pin (Not the firing pin, which doesn't fit through the hole) to push the extractor retaining pin out of the bolt, then remove the extractor assembly from the bolt. Scrub the extractor assembly, and scrape the lip in the extractor where it grabs the cartridge, removing any fouling build up. The only real thing to lubricate an extractor for is to protect it from corrosion.

Clean the firing pin channel of the bolt with a pipe cleaner and solvent, pipe cleaners with bristles work well.

Clean the inside of the bolt carrier with a solvent and tooth brush, a .45acp bore brush can also be of assistance to help scrub the walls of the bolt carrier. Using a scraper, scrape the back inside of the bolt carrier where the tail of the bolt sits. Using a tooth brush and solvent scrub the outside of the bolt carrier, inside of the bolt carrier from the back, and make sure you scrub the area where the two heads of firing pin sit, as there is usually a fouling build up found here.

You can clean the bolt carrier key (gas key) if you wish. This can be done with a pipe cleaner and solvent. Do not insert cotton swabs into this area, as you could leave the cotton swab behind causing problems, and if you break the stick off you will have bigger problems. This area needs no lubrication, as most bolt carrier keys are chrome lined.


Armorer level is basically the same as user level, with the addition of removing, cleaning, inspecting, and lubricating the ejector system.

If you wish to remove the ejector, you will need a 1/16" pin punch to remove the ejector retaining pin, it should go out either direction (Careful as the ejector and ejector spring is under tension and can launch if not careful). Once the ejector retaining pin is removed, carefully remove the ejector and spring, clean these with solvent and a brush, inspector for signs of stress, wear or breakage of the spring and replace when needed. Use a pipe cleaner and solvent. During installation, make sure you lubricate the spring, in Armorer Courses we teach to install the spring wet with a good lubricant as it helps protect it from corrosion, reduce friction, and a good lubricant should break the carbon down to reduce wear (Like an engine oil does inside of an engine). Use a 3/32" roll pin punch to install the extractor roll pin, which supports the roll pin and helps reduce the chances of damaging the pin, the pin only needs to be flush with the exterior of the bolt body and not countersunk as the pin is shorter than the depth of the hole (Those that are suffering from OCD can center the pin if they must, but again it isn't necessary).


CY6
Greg Sullivan "Sully"
SLR15 Rifles
TheDefensiveEdge.com
(763) 712-0123
 

Grayman

Established
#4
Greg thank you for such a comprehensive write up!

How do you feel about bore snakes? I see that you recommend brushes, jags and patches with a chamber guide. Is this only for deep cleaning or is this your normal field cleaning process for the bore?

Thanks
 
#5
IMHO, I will give you my $.02 Boresnakes and Otis Kit type cleaning systems, they work okay on the bore. What they don't do well is in the chamber. A chamber really needs to be cleaned with a chamber brush, as the rotating chamber brush is what loosens the fouling, allowing it then to be swabbed out.

We occasionally get to inspect a blown up firearm. Something I notice on systems like the AR15 / M16 / M4 / AR308 when blown up, is that most of them will have a heavy fouling build up inside the chamber, usually indicating that the chamber was not cleaned and this caused tolerance issues. Think of the fouling that is on the tail of the bolt, now being formed inside the chamber, especially where it necks down and in the throat, lead, and free bore areas. That fouling then becomes almost like a hard glass like substance. I look at it like this, what are diamonds made out of, which is carbon, now think of how hard that carbon is, and it now being built up and cooked inside the chamber. It doesn't take a whole lot of time to run a chamber brush inside a chamber, then clean the bore.

How I view the Boresnake or Otis Kit type cleaning systems is for a person to pull through the bore during training or competition sessions, when they have a few minutes of down time. They are also useful for a Soldier in the field as they pack down nice, and allow a pull through of the bore when it gets dirty or wet. What they don't do is a good heavy scrubbing, and don't do so well inside a chamber as compared to what you can do with the rotation of a chamber brush.

Personally I much prefer a cleaning rod over a Boresnake or Otis Kit type system. I keep cleaning rods in my personal vehicles, and in our work vehicles. As having access to a cleaning rod to swab something out is nice, but also necessary if you have a squib round that needs to be pushed out, stuck casing, or plugged muzzle where someone stuck it in the snow/dirt etc. I keep a multi-section collapsible cleaning rod in my range bag, and hunting packs in the field, in case I need to clean or push something out of the barrels bore/chamber, but I don't use them for regular cleaning, as the seam on the multi-section rods can flare up and scratch or damage the inside of the barrel with regular use, get yourself a good one piece rod for regular cleaning.


CY6
Greg Sullivan "Sully"
SLR15 Rifles
TheDefensiveEdge.com
(763) 712-0123