Divers Silicone Lubricant??
I’m new to PCP Air Gunning and enjoying setting up my Condor .22 but some things aren’t working as expected.
For one, I’ve seen the videos and articles that we should be using divers silicone lubricant in PCP air guns and by doing so, we should seldom need to clean them. Well, today, my Condor was starting to open up on the groups. I was trying a different scope, and shots were going all over. I got suspicious and ran a patch down the barrel.
I’ve had black powder smoke sticks that were cleaner. It took a stack of patches and about 20 minutes to get the gunk out. I’m surprised it was shooting as well as it did.
Contrary to what I had been led to believe, the divers silicone lubricant had been burning just like petroleum based lubricants.
So, what’s the story? Is there a lubricating product that resist burning under PCP pressures?
One thing that I really like about my CO2 powered air guns is they don’t burn the lubricant and seldom need cleaning.
Tuko
All Replies
Very good discussion on Krytox and air guns on this forum.
From that discussion, there may be a corrosion problem unless there is an additive to prevent it.
They are also expressing concern that once applied, it’s difficult to remove. That could be good or bad.
Near the end, there is a recommendation for Krytox® 2Cx Grease.
Thanks Dyotat,
Been looking for another, thinner option. The Krytox comes in many “flavors”; is the one you recommend the Standard GPL 205 (#10195K29) ?
I just checked my tube of Permatex dielectric grease and, sure enough, 100% Silicone. But also, the tube has a caution that it’s an eye and skin irritant.
Looks like I had air gun O-ring lub on hand and didn’t know it.
Thanks to bogman and everyone also.
Looks like this Silicone Lubricant really gets around under a lot of different names.
I was at the dive shop today and got my SCUBA tank topped off. Sure enough, it got hot being filled from 2,500lb/sin to 3,500lb/sin
Tuko
Just don’t lube your eyes with it! :rofl:
Knife
I use krytox 205 on all my o rings.
It is a little pricey but it is not effected by temperature. It also doesn’t have the consistency of peanut butter like divers silicone.
2 ounces is $46 at McMaster Carr
Thanks Knife
I just checked my tube of Permatex dielectric grease and, sure enough, 100% Silicone. But also, the tube has a caution that it’s an eye and skin irritant.
Looks like I had air gun O-ring lub on hand and didn’t know it.
Thanks to bogman and everyone also.
Looks like this Silicone Lubricant really gets around under a lot of different names.
I was at the dive shop today and got my SCUBA tank topped off. Sure enough, it got hot being filled from 2,500lb/sin to 3,500lb/sin
Tuko
It can also be found at auto parts stores in small tubes, usually by permatex. Butt there are other brands also. It is sold as dialetric grease for spark plug boots. Same=Same, just not a food grade as fund in divers grease. so if you don’t plan on eating your guns seals, 😆 It will work just fine! 😉
Knife
I need a beer!
Thanks guys.
Tuko
Tuko,
I’ve been shooting pcps and springers for over 30 years and do not lube the barrel. The outside, yes, to resist moisture, finger sweat, etc. If your pellets are dirty, study the clean and (barely) lube techniques for those. For o rings and other sensitive areas where tiny amounts of lube can get into the breech, I use silicone lube paste. It’s in the plumbing isle at Lowes, in small plastic jars (usually white). It’s often called “plumber’s grease” or “silicone grease”, but it has no petroleum; this appears on the labels. Oatey and Gunk market these. They’re cheap and usually easy to locate. I use the tiniest film on o rings, etc.
Oil filth in the barrel is coming from somewhere: barrel lube, pellet lube or ( :suprisedn: ) o rings disintegrating because they got exposed to petroleum.
TUKO, this is exactly what we have been telling you. The scuba tanks are being filled. So the pressure is increasing. Not decreasing. The large resivor tank, that is feeding the bottle WILL cool to an extent.
As to why the temp doesn’t drop when shooting, it is simply too small of an amount of air being released to show up as a cold bottle gun or bottle.
On the other hand, if you have had a bottle dump, (as many of us have), you will find that the tank will be cold. Nothing different than what the laws of physics indicate.
Knife
Except, I had the owner of a SCUBA store demonstrate to me that when Scuba Tanks are filled from air storage tanks of even higher pressure, the SCUBA tank gets hot? Hot enough that one will not hold a hand on one and, after filling, as the SCUBA tank cools, it’s pressure drops a couple hundred pounds. We can see the same thing when filling our PCP air gun tanks from a SCUBA tank. After closing the fill valve, the pressure will drop on the PCP air gun gauge. The air we put in the PCP air gun tank was hot and cooled.
I’ve also noticed that when shooting PCP air guns, even when shooting several shots in a row, nothing feels cold to the touch?
According to Charles, Boyle, Gay and Lussac, The SCUBA tank and PCP air gun should feel cold?
Is turbulence heating the air, offsetting the expected cooling? There’s something here that I don’t understand. The air is getting hot when it should be getting cold.
A tank that is being filled is experiencing a pressure build, hence the heat. The valve from the higher pressure vessel probably gets cold, but the vessel being filled gets warm.
The rifle won’t necessarily get cold through shots as the ambient temp negates the small amount of cooling.
Tuko,
You’re making me think to hard here :confusedn:
So am I to assume that the low atmospheric pressure is pulling the pellet out of the barrel or is the high pressure in the pcp tank pushing it ❓
OR, if they are working together can there be any significant friction between the two ❓
Turbulence in a hydraulic system produces enough heat that it’s a design consideration. Air is a fluid for these purposes, and so is susceptible to heating. I can’t imagine that’s the problem, though. I have wondered why I can’t sense any cooling when I pull the restrictor and really crank it up. I suspect it’s because it’s not enough change to amount to much. Of course, the thin-wall section of barrel doesn’t heat during heavy firing, either.
As for SCUBA tanks, the air in the tank and in the plumbing undergoes considerable compression while air from the reservoir gets minimal net expansion. I’d think it’d take a lot of plumbing to heat much, but I’m way to lazy to figure it out.
John
In Charles’s law, Boyle’s law, Gay-Lussac’s law and the Combined Gas Law,we understand that when air pressure drops, temperature drops.
Except, I had the owner of a SCUBA store demonstrate to me that when Scuba Tanks are filled from air storage tanks of even higher pressure, the SCUBA tank gets hot? Hot enough that one will not hold a hand on one and, after filling, as the SCUBA tank cools, it’s pressure drops a couple hundred pounds. We can see the same thing when filling our PCP air gun tanks from a SCUBA tank. After closing the fill valve, the pressure will drop on the PCP air gun gauge. The air we put in the PCP air gun tank was hot and cooled.
I’ve also noticed that when shooting PCP air guns, even when shooting several shots in a row, nothing feels cold to the touch?
According to Charles, Boyle, Gay and Lussac, The SCUBA tank and PCP air gun should feel cold?
Is turbulence heating the air, offsetting the expected cooling? There’s something here that I don’t understand. The air is getting hot when it should be getting cold.
The problem with using ordinary compressors for breathing air is that the piston rings create a region of high heat along their leading edge, causing micro combustion which produces CO which is harmful. I don’t get much fouling with JSBs, which are typically pretty clean. Eun Jin pellets are downright greasy in some tins, and they gook up my barrel in a few shots. I’ve concluded that the pellet lube “burns” from friction as the pellet moves down the barrel like a piston ring. I may be wrong, but washing pellets solves the problem.
John
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I use this
http://www.agscompany.com/lubricants/automotive/168
I has a -20* working temp. I was using divers silicone but at low temps with lead build up it can make things not work so well =)