True about Viton being incompatible with CO2. It is permeable to CO2. Actually there is a type of Viton that is compatible but the common kind we typically encounter is not compatible. It also swells in the presence of high pressure air but it does not seem to lose pressure so it works fine for static seals but the swelling can pose problems for dynamic (moving) seals. Buna-N on the other hand is just fine for CO2. Technically most common seal materials are permeable to CO2 to some degree. I don’t have the numbers in front of me but it is low for Buna-N. A recent anecdote, my SPA 600 has Buna-N seals and was put away last fall with a partial 12gr Powerlet. When I pulled it back out 5 months later, it still had pressure. That’s good enough for me to consider it negligible.
Sounds like a good way, Travis, if you don't mind the work of removing the barrel and O-rings.... I have always used Hoppe's #9 for all my PBs, it's nice to see a test that shows it is still one of, if not the, best.... I have always wondered what it did to O-rings so I have two 0.070 CS Buna rings, a 70D and 90D, soaking in it right now.... After over an hour there is no noticeable change in diameter or hardness, although it appears that the thickness has increased about 1% (roughly a thou)…. I'll leave them overnight and check them again in the morning.... I have used them on AG's before dried afterwards with a few patches and never had a problem.... but I thought a prolonged soak would settle once and for all if they will stand up to good ol' #9....Bob
I have a box of assorted HNBR from Harbor Freight. These are the WORST o-ring material I have ever used. They compress easily creep, deform and flow under high pressure. I use them when I want an o-ring that will conform to a shape and then stay in that shape even after pressure is removed. Certainly no good for anything airgun related in my book.
Quote from: T3PRanch on June 07, 2019, 01:36:18 AMI have a box of assorted HNBR from Harbor Freight. These are the WORST o-ring material I have ever used. They compress easily creep, deform and flow under high pressure. I use them when I want an o-ring that will conform to a shape and then stay in that shape even after pressure is removed. Certainly no good for anything airgun related in my book.You get what you pay for, agree with Nervoustrigger on the usual o-ring kits Durometer, too many unknowns / lies about what stuff really is.I don't buy from discount stores or auto parts stores on items like o-rings for HPA, I spend the extra $.20 ea and get a known material and known standard qualities.Please try some of the 'good stuff' and you might change your mind. Good o-rings are not THAT expensive.Cheap is good sometimes, sometimes not so much.
Quote from: Kinetic45^ on June 07, 2019, 02:09:03 AMQuote from: T3PRanch on June 07, 2019, 01:36:18 AMI have a box of assorted HNBR from Harbor Freight. These are the WORST o-ring material I have ever used. They compress easily creep, deform and flow under high pressure. I use them when I want an o-ring that will conform to a shape and then stay in that shape even after pressure is removed. Certainly no good for anything airgun related in my book.You get what you pay for, agree with Nervoustrigger on the usual o-ring kits Durometer, too many unknowns / lies about what stuff really is.I don't buy from discount stores or auto parts stores on items like o-rings for HPA, I spend the extra $.20 ea and get a known material and known standard qualities.Please try some of the 'good stuff' and you might change your mind. Good o-rings are not THAT expensive.Cheap is good sometimes, sometimes not so much. I pay about $2.00 apiece for 90 Durometer .097" cross section (Crosman) Urethane O-rings. Nothing else really works like Urethane in a prolonged CO2 environment. I just got off the phone with Tim at Mac 1. He uses nothing but Urethane in all his HPA reg rebuilds ( He replaces the cheap Buna-A seals) in ALL of his Co2 HPA, and PCP Guns. He uses all 90 Durometer Mil spec Urethane rings on almost everything. Reason, he said," I don't want my customers coming back after 2 years." Bottom line, the higher the Durometer....the longer the life of the O-ring.Concerning the main subject on "Bore Cleaning" Tim uses nothing but WD-40 down the Barrels with 3 or 4 passes to achieve a "Grey Patch" He explained that WD-40 is the best, safest, and most effective method to liberate lead from steel....and will NOT mess with O-rings. He explained that stripping, sanitizing barrels is really unnecessary, that, if the Barrel is really tight, you will initially loose a notable amount of velocity due to pressure decrease through the stripped rifling. He told me that Pushing 1900 FPS He'll run a patch through every 100 shots BTW, He also said, "Lead IS a natural lubricant!" The use of Hoppe's No9, Oven cleaner...whatever...is totally unnecessary because the only contaminate is Lead! I'll take it from "The Master" Use WD-40! Dave
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