N/A Fill Port Silicon Oil

I don't add silicone oil directly into the fill port, but I do add a small drop to the O-rings on each side of my fill whips. I guess that can be considered as adding silicone oil into the PCP system. On my Avenge-X it did not help or keep the O-rings from hardening and eventually failing. On my other rifles - who can say. Like you have mentioned in your post, small amount (very small) shouldn't hurt and may help. Don't know.

I use Super Lube Silicone Oil - High & Low Temperature stable from Amazon.

rdtricks said:

I don't add silicone oil directly into the fill port, but I do add a small drop to the O-rings on each side of my fill whips. I guess that can be considered as adding silicone oil into the PCP system. On my Avenge-X it did not help or keep the O-rings from hardening and eventually failing. On my other rifles - who can say. Like you have mentioned in your post, small amount (very small) shouldn't hurt and may help. Don't know.

I use Super Lube Silicone Oil - High & Low Temperature stable from Amazon.

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I also use the same silicone oil Super Lube Silicone Oil 100 cSt Part Number 56104 for various applications, and have used Permatex Super Lube Multi-Purpose Synthetic Lubicant with Teflon Item No. 82325 for many years for various applications including heat sink potting, and O ring lubrication. It is more recently replaced bySuper Lube with Syncolon PTFE Part No. CA21030- This is an NLGI GC-LB Grade 2 Food Grade grease.

There seems less technical data available for the oil.

I am also curious about any downsides to applying the oil into PCP air. "when chatting with tech support he mentioned to me about adding a drop of silicon oil into the fill port." is the first report from an authority. All other mentions have been of owners speculations.

Adding a drop of "Silicone" oil into a fill probe or at entrance hole on a foster fitting is to lube the o-ring that seals it ( Check valve )
Said oil will harm NOTHING ELSE in the pneumatic system !!
Said drop or several will never make it inside regulator even over time as area within air tank is vast and entrance into regulator sits mid air tube or receiver ... it's just not happening.

Bad o-rings, dry o-rings when assembled do happen & only way to lube and service these problem areas generally are by taking apart and servicing / lubing them when & where required.
Sure you'll read these miracle stories time to time ... tho in most instances when one has a high pressure leak, a simple drop of lube someplace curing it is far & away the exception, not the rule.

I use a Q-Tip and silicone to lube breech Oring that's about it however, most air tools like Nailers ETC use a drop or two of some sort of pneumatic oil to keep them lubed so who knows? OfCourse I would never use petroleum-based products internally on any of my air guns.

I think this may have come from the notion that adding a drop of Pellgun Oil on the tip of a CO2 cart will blow oil through the whole gun. I read about that a while back from Tom Gaylord, who was still pretending to NOT be Tom Gaylord at the time and was writing as BB Pelletier. I'd read it before where folks have translated that to PCP somehow and never bought into it.

The only time I've found that useful in PCP was with certain guns that would 'squeak' when filling, in particular the older Evanix guns. A drop of silicone oil (not Pellgun oil) on the foster fill would quiet them down.

What Motorhead above said! It keeps check valve in fill port from sticking closed (a not uncommon problem). Used sparingly it causes no harm.

The only of my guns that squeak when filling are 2 of my Nova Vista Liberty's. No problem holding air but it's annoying when filling. I will try a few drops next time I fill.

I have two fill lines in active duty.
One is for my Leshiy2 with an Easyfilll, and the other I am using for tethering my BR Impact variant through a Huma externally adjustable regulator.
I am regularely "greasing" all the quick disconnect orings with silicon oil,
also
2-3 small drops of PTFE oil inside the hole of the hose line- from entry end.
The air pressure will distribute the thin layer of lube all over the gun internal air path.
Doing this for years

Jalan said:

Hello All,
I've seen a couple threads discussing this but none really gave a clear answer.
I recently had the reg fail in my 3 mo old A.V. Avenger Bullpup 2 (25 cal). Tech support was great. I decided to send it in for warranty repair vs them sending me the reg.
I only mention all this as when chatting with tech support he mentioned to me about adding a drop of silicon oil into the fill port.
From what I've seen guys are on both sides of this. I first thought maybe it falls into the 'Can't Hurt' so why not category. But now I'm not so sure and thinking what really is the benefit? Is that drop atomizing to reach all the little places it needs to be? I would guess anything more than a tiny drop could cause some problems.
Ok. I believe I'm overthinking this. I would really appreciate any thoughts.
Thanks in advance..
PS: Advice of the silicon oil best used in general would also be appreciated. Thx

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According to ChatGPT:

• FX: No official guidance—stick with caution. Many avoid silicone on metal surfaces.
• Air Arms: Strongly avoid silicone oil in the system unless you want to risk losing your warranty.
• Umarex: Permissive for certain models—especially the Gauntlet—with their own chamber lube; many users find it helpful when used as instructed."
  
  Air Arms are reported to state: “Air Arms very clearly states if silicone oil is found in one of their airguns then the warranty is void.”
  
  Umarex are reported to recommend:
  Umarex
  
  A manual excerpt via a forum user notes regarding the Umarex Gauntlet:
  
  “Apply a drop of RWS chamber lube on the tank’s O‑rings and also into the valve hole where the tank screws to the block any time the tank is taken out.”.
  
  Does anyone know what RWS chamber lube is?
  
  
  I am unclear as to risks of silicone oil regarding O rings as we routinely used silicone oils and greases as O ring lubrication, dielectric compounds in electric and electronic connections, module heat sink potting, etc.
  
  My overriding concern is to evaluate these issues with more than uninformed opinion, as we all know how prolific that is.

putting a drop every 3 fillings on my Avenger X fill port helped a lot with the regulator. It is still not great but it does at least now hold some pressure for a while.

Normkel said:

According to ChatGPT:

• FX: No official guidance—stick with caution. Many avoid silicone on metal surfaces.
• Air Arms: Strongly avoid silicone oil in the system unless you want to risk losing your warranty.
• Umarex: Permissive for certain models—especially the Gauntlet—with their own chamber lube; many users find it helpful when used as instructed."
  
  Air Arms are reported to state: “Air Arms very clearly states if silicone oil is found in one of their airguns then the warranty is void.”
  
  Umarex are reported to recommend:
  Umarex
  
  A manual excerpt via a forum user notes regarding the Umarex Gauntlet:
  
  “Apply a drop of RWS chamber lube on the tank’s O‑rings and also into the valve hole where the tank screws to the block any time the tank is taken out.”.
  
  Does anyone know what RWS chamber lube is?
  
  
  I am unclear as to risks of silicone oil regarding O rings as we routinely used silicone oils and greases as O ring lubrication, dielectric compounds in electric and electronic connections, module heat sink potting, etc.
  
  My overriding concern is to evaluate these issues with more than uninformed opinion, as we all know how prolific that is.

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I think it is generally agreed that a small amount of silicone is fine on O rings that need lube (some do not). The "bad press" on silicone comes from its misuse as a metal-to-metal lube, something for which it is not designed. This can also occur if silicone is used (especially over used) in places where it can migrate to such metal surfaces or threads. It can (and has) caused certain metals to seize when used in a high pressure/high temperature setting. There are not many places in most air rifles that need lubrication. Use a small amount of the correct type of lube and life will be good.

elh0102 said:

I think it is generally agreed that a small amount of silicone is fine on O rings that need lube (some do not). The "bad press" on silicone comes from its misuse as a metal-to-metal lube, something for which it is not designed. This can also occur if silicone is used (especially over used) in places where it can migrate to such metal surfaces or threads. It can (and has) caused certain metals to seize when used in a high pressure/high temperature setting. There are not many places in most air rifles that need lubrication. Use a small amount of the correct type of lube and life will be good.

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I am troubled by the generic "silicone" that many seem to apply without context. As you know, "silicone" is an element closeby carbon on the periodic table*

*NB. You know this so my intent is not to lecture but for context. Please excuse if this appears condescending as I am only looking for clarification as to what people mean by many of the claims. The metal corrosion or thread concerns are not articulated clearly, IME.

A silicone compound that has similar properties to those of a carbon compound, has similar properties so one needs to consult the properties of the compound rather than to jump to conclusions based on the label.

Some silicone greases or oils have good high-pressure lubricating characteristics, as do some carbon based greases or oils, and others have poor HP characteristics. I am trying to work out what people mean when they say "silicone this" or "silicone that".

If one checks the data for Super Lube Multi-Purpose Synthetic Grease NLGI GC-LB Grade 2, it seems evident that it is more than capable for high-pressure (high contact pressure) applications such as PCP guns. Slding friction applications, anti-galling, etc. seems well covered.

Oil and grease conversations can be the most tedious threads on line as the general public exhibit the most extreme Dunning-Kruger Effect regarding lubricants, IMO.

I think the many lubes available are confusing as it relates to silicone. For example, the Super Lube Multi-Purpose Synthetic Grease does not contain silicone, although it is routinely confused with the company's silicone based grease. I've decided to err on the conservative side and just don't use silicone in my air rifles and firearms.

elh0102 said:

I think the many lubes available are confusing as it relates to silicone. For example, the Super Lube Multi-Purpose Synthetic Grease does not contain silicone, although it is routinely confused with the company's silicone based grease. I've decided to err on the conservative side and just don't use silicone in my air rifles and firearms.

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I think that people are confusing the term "silicone" as indicating some product or class of products. What is it that "silicone" indicates that doesn't require more indepth information to describe the product in question? Silicone is an element in the same relative area as carbon on the periodic table.