Viton "O" Rings?

[Myrkul]

A while back I was doing a rebuild on a friends F-2 illustrator. Considering the age of these things, I figured the first step would be to replace all the seals.

Upon opening it, I immediately noticed that the "O" Rings were brown, not the mushy and rotted black Buna I was expecting. When I started pulling the "O" Rings I got another surprise. They were still springy, round, and not even the least bit rotted or deformed.

Curiosity got the better of me, so I slapped a siphon tank on it, and sure enough, it aired up with the original "O" Rings, zero leaks. Once a quarter of a century plus of old paint was cleared out of it, it cycled perfectly fine as well.

I did a quick Google, and it appears that the shelf life of Viton is 20 years, which is a great deal longer then that of ordinary Buna. Even more googling, and it appears that viton "O" Rings are also available in most standard sizes and durometers from Amazon.

So, I guess my question is: Is there any reason to not just place a couple bulk orders and start slapping these things in a lot more markers? The idea of not having to worry about "O" Rings going bad from a gun sitting for a decade plus is extremely appealing from both hoarder and a maintenance perspective.

Thoughts?

[BrickHaus]

You know more about o rings than me, bit from a little research viton has poor cold performance.

So for a co2 fes shooter you would think they aren't the best.

The other downside I found was they can offgas in the event of a fire. Not sure if friction from using them as dynamic seals would cause the bad chemicals to off gas also, but it would make me leary of them causing health issues over time.

[latches109]

HBNR, Viton (FKM) are fine replacements for standard NBR (Nitrile). Viton I have is 25yrs shelf life, NBR is 15yr shelf life. fyi the amazon Viton (FKM) are not very good - maybe a different seller could be. https://www.globaloring.com/ or https://www.theoringstore.com

[OpusX]

In this thread I learned things.

[Trbo323]

Viton are a pretty good replacement for Buna. Ghille-Man has done viton rings in vanguard demons and they typically do better with them than the standard Buna. The only real down side is cost

Sent from my motorola edge 5G UW (2021) using Tapatalk

[wthomas333]

I have used them from time to time without a problem. Some of them come in a slightly harder 75 durometer. So if you want something in-between they are good. McMaster-Carr has a large selection of them as well.

[flyweightnate]

To answer a few questions:
They only "outgas" over 460F, when they begin to release the fluorine and make hydrofluoric acid. It's only an issue if you're trying to burn off adjacent red Loctite. But then, it can be a big issue.

They do tend to be stringy, and less wear resistant. They're not generally recommended for dry dynamic applications for that reason.

There are different "cures" of FKM, some with peroxide, some with... oh, I forget. But they will behave differently. I think Parker and theoringstore.com have explanations.

My recommendation?

HNBR.

It's a more saturated NBR that retains all the best properties - wear resistance, resistance to set, lubricity - with better crosslinking, so they last longer. They're tougher, more chemical resistant, and a cool green color, usually.

But with any elastomer, quality is important. Don't get the Harbor Freight set - they're horrific. Go to theoringstore.com and get good, high quality rings, and you'll be good for quite a while. Pick up some Superlube while you're at it for the static seals.

[latches109]

https://www.espint.com/products/o-rings/fluorocarbon-fkm-o-rings

this site has good diagrams and explanations

[Myrkul]

What is the shelf life of HNBR?

The only "O" Rings I've ever actually worn through are the crappy colored kit ones. My collection is getting kind of bloated at this point, but I still make an effort to rotate through most of it in a given year. Obviously my favorite guns get used more, (and oddly seem to need repairs less) but there is a large handful that probably take 5 years before they get through a full case of paint. Those guns oddly seem to need new "O" Rings the most often, so I was thinking that by switching to something more age resistant I could save myself quite a bit of time.

[Toestr]

The main advantages of buna is that it's the cheapest material cheap and very resistant to solvents.

You'll probably be ok replacing any buna seals on HPA only guns (especially staic seals) but if it's a critical high wear dynamic seal or you're using CO2 stick with urethane. Urethane has the best abrasion resistance (if you've ever gotten a pin prick in a nitrile glove you know that it will be completely shredded in a minute) and cold resistance but is also the most expensive material. Urethane is typically used for things like reg pistons and blowback hammers.

My rule of thumb is if the gun works fine stock just leave it as is (ie I won't be changing all the dynamic seals I my Emek to urethane). If a gun was made with CO2 in mind I might replace the static urethane seals with bunanin I'm using HPA since it's cheaper and lasts longer than urethane.

[infamoussmiley]

A while back I was doing a rebuild on a friends F-2 illustrator. Considering the age of these things, I figured the first step would be to replace all the seals.

Upon opening it, I immediately noticed that the "O" Rings were brown, not the mushy and rotted black Buna I was expecting. When I started pulling the "O" Rings I got another surprise. They were still springy, round, and not even the least bit rotted or deformed.

Curiosity got the better of me, so I slapped a siphon tank on it, and sure enough, it aired up with the original "O" Rings, zero leaks. Once a quarter of a century plus of old paint was cleared out of it, it cycled perfectly fine as well.

I did a quick Google, and it appears that the shelf life of Viton is 20 years, which is a great deal longer then that of ordinary Buna. Even more googling, and it appears that viton "O" Rings are also available in most standard sizes and durometers from Amazon.

So, I guess my question is: Is there any reason to not just place a couple bulk orders and start slapping these things in a lot more markers? The idea of not having to worry about "O" Rings going bad from a gun sitting for a decade plus is extremely appealing from both hoarder and a maintenance perspective.

Thoughts?

Hello

Viton supposedly does not spring back and hold shape after a while. Viton tends to deform easily. But Viton is resistant to moisture and gas, and various chemicals.

Warmly,

Smiley

[Toestr]

My early F4 had urethane for everything that held a seal.

[Chappy]

I can’t confirm but I really seem to remember f1s having urethane. I think yours was rebuilt at some point.

[Toestr]

Anyone here familiar with the durometer of orings in an illustrator?

[crazyboy78]

I recall using some VIton 004 o-rings as replacements for my Tiberius 8 mag valve seals. They worked well but were prone to chunking apart. They were usually good for about 20-ish mag changes before needing replacement. But they were cheap enough.

[latches109]

HBNR is my favorite too. Last and wear better than standard NBR, comes in 70D, 75D and 90D, green and black.

My first order from global oring came in and I would recommend them. Orings are fresh and shipped same day. I am not affiliated with them at all. “The oring store” upped their minimum qty and prices. https://www.globaloring.com/

i went a wild and ordered a few sets of each kind of 003 for 3 ways. Going to see which is best.

[Myrkul]

This is glorious!!!