CO2 Seals. making them last longer....

[S_Bluck]

Hi All....
This has probably been asked here many times before.. BUT what is the best way of
getting the longest life from the CO2 seals in your air-pistol? I have a couple here.
both use the usual 12g? capsule. and I was just wondering if special oils are a good
way to go.. OR should a capsule be kept in the pistol to keep the seal correctly-shaped.?
In the past I have kept a new capsule in my CP88 but only gently (not fully in and pierced)
is this a good or bad thing to do? Any ideas gratefully Rx'd

[blooregard]

My view often seems to be fairly controversial. However since CO2 guns came off ticket, and having owned over 30 of them and never had to replace a seal, I think it is valid. I've actually had a Umarex pistol fall apart on me due to metal fatigue before it's seal failed.

Keep them lubed with something like pellgun oil when replacing a cartridge, and do not replace cartridges too often or too soon after shooting. NEVER remove a cartridge with a good amount of CO2 in it as the seal will expand due to pressure relief and the CO2 will vent across it causing a rapid temperature drop and contraction.

Mechanical expansion with temperature induced contraction is not going to lead to a reliable seal, you will end up with a warped or cracked seal that will not hold gas.

Other's wouldn't dream of leaving a gun with a CO2 cart in it. For me the only issue is safety, but as long as it is cleared and secured I see no reason not too.

As others will have different views I can only give you this advice, listen to everyone and ake your own mind up, but most of all don't worry about it too much!!

[S_Bluck]

Thanks blooregard.. Cool advice.!.

I have just ordered some pellgun oil.... I didn't think about the temperature change. I
usually plink about 5 to 10 magazines through it in the garden. and this uses pretty-much
all of the CO2 in the cartridge. and it's usually cold but not freezing...

I do occasionally put the pistol away with gas in it (but open and no magazine).
But only if I'm going to use it again very soon.. I am in the habit of using it all up and
taking out the empty capsule. But I generally leave a full one in the pistol un-pierced.

I will start using pellgun-oil and try not to send the thing into thermal shock by shooting
off dozens of rounds quickly......

If I want to drop the last bit of CO2 out at a sensible rate to avoid excess cooling is there
a preffered method... Pointing in a safe direction and continuously pulling the trigger
just seems like a good way to wear the pistol out... After about 10 mags of 8 pellets I
can often just push the hammer in a bit and allow the excess CO2 to escape. But this
more rapid release will cause the capsule and the seal etc to chill.....

Thanks.

[PaulR]

You could also use Crosman Co2 cartridges which have Pellgun oil in them.

I tend to buy 100 CO2s at a time online and go for the cheapest option - they can sometimes be Crosman believe it or not. If using others then a drop of Pellgun oil every third cartridge will keep things sweet.

TBH - I have quite a few CO2 pistols and only had one seal fail over the last few years (and that was on a 50 year old Crosman 600 on it's original seals) and this is regardless of whether they are stored with or without a charged cartridge installed.

[Benelli B76]

Nitrile and Viton seals which are usually the black type rubber seals that are used can absorb CO2 in its liquid state and expand when exposed to the air. They do return to standard size after a time as the gas evapourates from the rubber. Polyurethane is the best material for seals and is usually any colour from almost clear to red green blue etc depending on the dye colour used by the manufacturer. Polyurethane does not absorb CO2 and is usually also a higher Shore hardness around 90 degrees to 95 Shore A. All the seals benefit from a smear of clear silicone grease.

Baz

[airgunnut]

http://www.co2airguns.net/CO2_Links/index.htm
This has links to some good articals about co2 (the collection is worth looking at as well)

[Benelli B76]

Another point to mention is that some older polyurethane seals suffer from bacterial degradation and can crumble or become softer and lose their resilience. I have just resealed an old Smith and Wesson 79G that had this problem, and it is often found in old Original 6 piston seals. If you can cut or mark polyurethane easily with your finger nail it has a problem.

Baz

[Aimstraight]

I once bought a used C02 pistol that have a deep imprint on the C02 bulb seal, which did not seal particularly well when the bulb was loaded, for this reason I prefer not to leave the bulb in for extended periods. The point made about not releasing/venting off CO2 onto an expanding seal seems very valid.

If I occasionally leave a CO2 bulb in an unloaded pistol for a few days (to finish off the gas later), I place a rubber band around the barrel and trigger guard.
This way if I go back to it later than planned, the band serves as a reminder that it is gassed up. The Postman used to drop red bands all over the place which were ideal.

I am convinced that the Umerex bulbs also contain a lubricant but have never seen it mentioned when on sale.

There are a few threads on bbs where folk have had the valve seal stick open, causing all the C02 to vent down the barrel. In some cases, they found that Pellgunoil resolved the issue. I am a great believer in the occasional use of a lubricant (Pellgunoil or a bulb containing lubricant) after having a problem with the valve seal in an SSP pistol that leaked. Strip down showed that the internal valve seals were bone dry and failed to seat properly; Pellgunoil fixed that.

[airgunnut]

I am convinced that the Umerex bulbs also contain a lubricant but have never seen it mentioned when on sale.

I was told the crosman bulbs contain lubricant, the umarex bulbs that have the lube in are the ones labled maintenance, usually sold in boxes of 5.
But thinking about this, the co2 is liquid due to the pressure it's under, can oil mix with this liquid? If it can then when the co2 bulb is pearced the liquid vaporises, co2 boils at a stupidly low temp so as the pressure drops liquid co2 becomes a gas that propels the pellet, the thing is oil vaporises at a much higher temp (well over 200 C) so when the co2 becomes a gas the oil will be left behind, won't it?