Air Arms Rifles & Vortek O-ring piston seal resolve ...

[Motorhead]

Well, been nearly a year fooling with my own TX 200 along with quite a few customers AA spring guns ( HC and PS's also )

Have found the O-ring piston seal that comes with the PG2 kits is IMO in need of being used within compression tubes that have been further honed to a finer surface finish of 600/1000.  While the O-ring does work on the factory surface finish, am seeing the o-rings service life as pretty short ( 3-5K cycles )  This figure can be +/- that count pending lubrication type and amount however.
A finer surface finish abrades O-ring less and does seem to help further o-ring life and maintaining a 100% seal between service intervals.

Next observation is that the O-ring type seal with its generally freer motion can be more consistent shot to shot ... This while the O-ring fit to the compression bore is optimal.  * A fitted parachute seal works as well.
Sadly tho have found the wear & sealing qualities happening to the o-ring degrades so quickly the shot cycle start happening faster due to compression losses having piston slamming into roof of compression chamber.  Shot cycle while still smooth gets a harsh snap that you can see in the sight picture ... Following threw with the shot becomes more difficult and 1st indicator somethings amiss.
Velocity drops a tad but seemingly not enough so to Red Flag there is an issue 
* Now it could be argued CHANGE RING SOONER ... Yea, true enough if a service nut and mechanically inclined enough to detect the shot cycle degrading 

So what this brings up is .... Shooting these rifles with the O-ring type seal makes them a LOT MORE unreliable in terms of Pick it up and just shoot it !!

Have gone back to Parachute ( OEM ) type piston seals finding if you take / make the effort to get a good fit has JUST AS FREE motion as the o-ring type with what is of my opinion multitudes more service life before needing to be fooled with or serviced.
* Also found the shot cycle vibration to be just a tad softer using a parachute seal over the o-ring type.

Your results may differ, just sharing what I have concluded as valid FYI to those using this Seal sets in there AA spring guns.

Regards,
Scott

[fusion]

Scott, awesome post!  Thank you very much.
How do you fit a parachute seal?  What is the preferred technique?
Thanks again.  Mike

[Springrrrr]

I read an article once that backs up your findings.  An "O" ring seal works best with smooth walls on the compression tube where a parachute seal likes a honed surface that holds the lub similar to piston walls in a car's cylinder holds oil.

I have tried the "O" ring in my TX200 and went back to the parachute in a very short time.  The Tx has a nicely honed wall straight from the factory.

[Sfttailrdr46]

  Thanks Scott I was thinking about the O-ring when I did the Vortek kit last month  but will stick with the Parachute seal since I bought a couple extra for the TX when I first got her from Oakey last fall. I replaced the seal when I install the Derlin spring guide you sent me also honed the cylinder at that time also.

[Dockey 454]

   Scott that is what I had in my head. Last summer I put the #14 Kit in the TX, with Krytox lube. It shot fantastic. I opened it up to have a look after 3.5k shots. It still shot great, but had to look. What I found was t he O-ring chafing. The only thing I could come up with was the cross hatch was a little coarse for the ring. Went back to the Vortek parashoot seal. Still shoots great, but lost a little FPS. Take a look at the pic, and you can see the chafing in one spot.
          Tom

[Motorhead]

   Scott that is what I had in my head. Last summer I put the #14 Kit in the TX, with Krytox lube. It shot fantastic. I opened it up to have a look after 3.5k shots. It still shot great, but had to look. What I found was t he O-ring chafing. The only thing I could come up with was the cross hatch was a little coarse for the ring. Went back to the Vortek parashoot seal. Still shoots great, but lost a little FPS. Take a look at the pic, and you can see the chafing in one spot.
          Tom

Yup ... that is typical damage. ( Fretting I would call it )
O-rings are by design STATIC seals meaning that they seal on a motionless part.  While an o-ring can and will seal with Rotating and Linear motion, Surface speed between parts being sealed is the enemy of such use.  Of which used as a piston seal is FAST !!

[EMrider]

I have had a vortek oring piston seal on my workbench for the past two years.  Never had confidence in the oring seal design.  The standard OEM parachute seal has given me very consistent velocity for 25k or more shots so was reluctant to swap. 
R

[mtsheron70]

Have a good friend who places well in State level FT shoots (and one national event) he has tried the oring kit (several times in off season) and finds there is really no way to make one last for one entire season so has given up on them, not nice to rebuild it more than once in a season. Might bbe better suited for someone with one .22 that hunted and only fired 1,000 per year.
John

John you are right.  I have never liked or understood how long that system would take the constant movement and tight fit.

[Brazos]

I asked this question a few days ago and the answer was use the oring.  Then this post is anti oring.  I am going to install a Vortek SHO kit this weekend and was not going to use to oring seal, then I was convinced to try it.  Now I am not.  For all the reasons above.  Those were my fears plus the oring breaking loose.  After looking at the oring and the seal I am not so much worried about it breaking loose.  The other reasons you guys stated confirmed my fears.

[Dockey 454]

I asked this question a few days ago and the answer was use the oring.  Then this post is anti oring.  I am going to install a Vortek SHO kit this weekend and was not going to use to oring seal, then I was convinced to try it.  Now I am not.  For all the reasons above.  Those were my fears plus the oring breaking loose.  After looking at the oring and the seal I am not so much worried about it breaking loose.  The other reasons you guys stated confirmed my fears.

      I wasn't going to use the O-ring, but thought I would give it a try. I'm sure if the compression chamber was smooth it would have worked better.
          Tom

[Brazos]

I will see how smooth it is when I open it up and make a call.

[TooJung2Die]

Not an AA air rifle but I have the Vortek o-ring seal in my RWS 45. It replaced the original leather seal. The gun is over 30 years old and has not be honed. The cylinder is mirror bright so I decided to use the o-ring instead of a parachute seal. O-ring lube is Krytox GPL 105 oil. Though it only has about 1000 shots through it I'm very happy so far. Velocity with 8.3 gr pellets exceeds original factory claim of 830 fps. What I like most is the first shot consistency. It doesn't need a few warm up shots like all the other parachute sealed air rifles. When I take it out the first shot POI is right where the last shot was when I put it away a week or more ago.

Vortek included a second o-ring in the kit. Maybe they don't expect them to last very long and spare will come in handy? My $.02 so I can follow this thread.
Jon

[Pappy]

I didn't see it mentioned here, but what do you think is the life cycle of the OEM parachute seal is ... in a stock MK3?  Just curious.
Thanks;
Allan

[mtsheron70]

I didn't see it mentioned here, but what do you think is the life cycle of the OEM parachute seal is ... in a stock MK3?  Just curious.
Thanks;
Allan

Not sure Allan but I would say you will get varied mileage of course.  I have opened up rifles with parachute seals that have in excess of 30K + shots before a issue was noted.  Then I have heard of less of course.  I think sometimes it may be a list of things that gets the varied mileage...........improper install < mainly damaging the seal upon install; a faulty seal that for whatever reason has a manufacturer flaw not visible to the eye; or a rifles chamber that may have had debris or a rough chamber surface that will affect a seal to premature failure.

I don't think anything is a constant when we are discussing mechanical parts and the way they function.

[EMrider]

I didn't see it mentioned here, but what do you think is the life cycle of the OEM parachute seal is ... in a stock MK3?  Just curious.
Thanks;
Allan

From my experience, good parachute seals (vortek or ARH) last considerably longer than springs. 

I have a couple seals in springers with way more than 30k shots.

R

[Motorhead]

Being we're talking Air Arms rifles here .......
With there precision honed compression chamber bore that creates very little wear on the OEM type parachute seal, have seen rifles shot in excess of 30,000 cycles that upon removing and inspecting the original seal it was still in serviceable & useable condition.

[TooJung2Die]

All industrial pneumatic or hydraulic o-ring sealed cylinders I have seen have highly polished, chrome-like finishes with no cross hatching. I would conclude that for an o-ring seal to last in an air rifle the compression tube should have the same polished surface.

[Brazos]

I just installed a Vortek kit in my TX a few hours ago and the compression chamber is very cross hatched (nicely done I might add).  Due to this I left the stock seal in place.  Looked like a nice, heavy duty seal.

[Sfttailrdr46]

  I left the stock parachute seal on my TX200 MK III when I did the Vortek kit 2 weeks ago for the same reason . It looked fine under my lighted magnifying glass and I am way too lazy to do the mirror polish job on the compression tube