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Umarex Looking for Polyurethane sheets, 2mm thick and 90A durometer for CO2 seals

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Bluemill

Member
Mar 14, 2023
30
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Scituate, MA
Looking for Polyurethane sheets, 2mm thick and 90A durometer for CO2 seals

The heading says it all but I'll elaborate. I have been successful with 80A durometer poly sheet but the seals will only take about 3 CO2 cartridges before the seals fail. I'd like to try a 90 to see if that improves durability. The closest I have been able to buy is 80A, 2 mm thick. Please advise if you know of any to buy. Thanks!

Bluemill
 
If 80 durometer is failing after single-digit cartridges, 90 durometer will not be meaningfully more durable. Are they failing by getting mashed forcefully and permanently deforming? If so, the solution is to figure out why so much force is being applied, or why it is necessary to apply so much force. A gas-tight seal at the nose of a CO2 cartridge should not need so much squeeze that it damages a polyurethane seal so quickly.

For example, if the act of installing a new cartridge places a lot of squeeze on the seal before the piercing feature breaks through the cartridge, that may be the culprit. In which case it might be a simple matter of backing down from 2mm stock to 1/16" stock.

I know in prior threads you have detailed a number of different trials and experiments you have tried, and unfortunately I can't remember everything with sufficient detail so if I'm repeating earlier advice that didn't work or isn't relevant, my apologies.
 
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There's these square cut o-rings they make from either a sheet or turned on a lathe.

Square-Profile O-Rings

Standard AS-568 size Rubber Square Rings can sometimes be used interchangeably in AS-568 standard size O-Ring gland designs. Square Rings can be used in static applications where high sealing load force is required or when the sealing area is too thin to accommodate anything else. In most static...
www.theoringstore.com

Contact the manufacturer, who may be able to get you a source of sheet materials you want. They may even have a seal the right size that will work for you.
 
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the main problem is finding material at a price with shipping that is less then the factory seal
you are still after the seals for the PPK/S
DonR will have to tell us how to buy from them because there is no exit from the cart it looks like you get a quote ever though there was a price
i have some 3.22mm black urethane hard as hell, i used it to make stem seals for S&W 78-79G's
year ago you could find it on Ebay at cheap prices but the cheap prices are gone and the product selection is thin
now there is polyurethane rubber and urethane sheet good, the rubber you do not want
the sheet goods is as tough as can be
it is a hard nut to crack
so, a side thought
i have in the pass tried to solve a problem but all i got was a square peg for the round hole i needed and wasted too damn much money out of stubbornness and i still do it, just a thought
i will search for some 2mm material i have lots of time but you get a sheet at 20+ bucks cut some pieces and it fails like now
and i have boxes of stuff that did not work we all will get there in time

mike

if the material that you are using can be compressed with your fingers it is not the right material
 
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thanks Don i will do just that
i did find some on Ebay that looks good but listed at 75 dura and the poster said he had 80 already
urethane as you know is very hard and 90 dura buna doesn't even have the same fell as 90 dure urethane
quite frankly the dure rating on sealing type of material is vague at best to me
the problem with forums in general is that we have to guess too much because we do not have a gun per say or material in hand
so we help by pointing and hoping what we are pointing at is correct
in this case i would thing that 80 dure in urethane would be as tough as anything out there but in this case it seems to fail and here is the rub you, me or anyone doesn't know for sure what the material is, as stated urethane 80 dure but as stated it should be fine but why isn't it
the only thing i can think is the material is urethane but the wrong type but here we go with the guessing game
i like to help but hate to guess on anything
questions and no answers but as the try and fail process goes it get very expensive

thank you Don for the info
 
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TheBeardedGunsmith said:
I bought a 1/16 thick 6"x6" sheet on Amazon a few weeks ago for an airgun project and it worked perfectly. It should work fantastic for a co2 seal.
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Teflon is terrible for a co2 seal. It scars and takes a set. The short piercing pin requiring thinner material as posted above is the likely culprit. I have seen piercing pin seals thinner than 1mm. I may not be replying to the correct post. You mentioned teflon, so I reacted. The short piercing pin and need for thinner material was mentioned by nervoustrig . Teflon can seal very high pressure, we even used in paintball at one point, just not for piercing pins becuase any abraded material would end up imbedded in the teflon. I have no idea why everything is coming out in big letters.
 
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yes at 1.5mm+ it would seem to be a great source of material
i have a bad habit but i think others should do it
as time goes on you pick up more and more guns, or at least i do somewhere at 100 but my point is if you read a post like this what do you do
well, what i do is buy some of the material in this case or at least search it out and when you have a need or idea, you have it on hand
and it called boxes of stuff
i bought some .3mm and .5mm Teflon sheet good and use it as fill material in the rear cap of Giss System pistols, at those 2 thicknesses i can make any mm thickness i want and it works great

tricks, ideas and imagination are a tinkerer's best friends

1.5mm could be used to make cart seals for the Gamo R-77 maybe
 
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marflow 777 said:
to tell you the truth Teflon has never been tries by myself
when the 850 forum was up and running the point of using urethane seals was hammered into us and has been my opinion from that point on
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It works fine. I've personally used it and my compressor even uses it as a seal against brass from the bleed valve. It doesn't need cranked down on so it doesn't deform as suggested.
 
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