Anyone know just why they use the poly O rings instead of nitrile, viton etc? And has anyone changed, them out for an alternative?
Skout Why do Skout use Poly O rings?
- Thread starter Tricky-Dicky
- Start date
I asked them personally while I was there. They feel they are just better and chemically resistant. Just don’t deform from prolonged exposure to what we use for assembly. Like probably many other long time PCP guys, I was curious seeing my gun full of paintball orings. But I also have a few guns left with paintball regs on them and no issues. So I’ll try not to concern myself with it until I have an issue that points a finger at those orings being the cause.
Upvote 0
That is an interesting response from them. All 3 materials (Buna-N, Viton, and polyurethane) have excellent chemical resistance to anything commonly used in airguns.
And the statement about not deforming is counter to industry guidance about polyurethane, which is that it is more susceptible to compression set than the other two. If instead the rep meant resistance to extrusion, that is more a property of durometer.
Where polyurethane excels is where abrasion is a factor, such as a breech O-ring (pellet head and skirt push through it) or bolt O-ring (rubs the barrel leade when seating).
And the statement about not deforming is counter to industry guidance about polyurethane, which is that it is more susceptible to compression set than the other two. If instead the rep meant resistance to extrusion, that is more a property of durometer.
Where polyurethane excels is where abrasion is a factor, such as a breech O-ring (pellet head and skirt push through it) or bolt O-ring (rubs the barrel leade when seating).
Upvote 0
That's exactly what I thought and one of the reasons why skout recommend de pressurising if not using for more than a couple of weeks, yet I can leave my other PCPs pressurised for more than a year without leaking, but the Epoch does loose pressure which is why I asked if anyone have changed them.
Upvote 0
For what it’s worth, I don’t think compression set is responsible for the pressure loss but it could be because of insufficient hardness (durometer).
Upvote 0
My thoughts exactly. But we will see. They seem to be committed to them in most but not all of the gun.
Upvote 0
Probably. Because paintball guns don’t get stored under pressure. But interestingly enough when I get home from this trip tonight, I will screw a bottle onto my Skout and start drilling the center out of my 75 yard target.
Upvote 0
I spoke to an engineer at an oring manufacturing plant about polyurethane a couple years ago.
He said Buna is good for static applications. Poly. is for maintaining a seal with moving parts and wear resistance.
I have 2 -90 durometer. polyurethane orings inside of a balance valve I made that has been under pressure for 2 years.
Literally many thousands of rounds without any leaks. So I don't think polyurethane is the problem.
He said Buna is good for static applications. Poly. is for maintaining a seal with moving parts and wear resistance.
I have 2 -90 durometer. polyurethane orings inside of a balance valve I made that has been under pressure for 2 years.
Literally many thousands of rounds without any leaks. So I don't think polyurethane is the problem.
My experience leads me to agree with this.
Upvote 0
I was questioning this 2 years ago when I first started my internal work on my EPOCH ... made no sense to me either 
Upvote 0
I do not have any leaks..no pressure loss over time when pressurized
when the valve is shut off...the bottle retains it's pressure
I did have a bad ring, but that was my fault, that resulted in a slow leak
it was really hard to find, but the silicon oil did a little better than soapy water to reveal the location of the tiny leaks
when the valve is shut off...the bottle retains it's pressure
I did have a bad ring, but that was my fault, that resulted in a slow leak
it was really hard to find, but the silicon oil did a little better than soapy water to reveal the location of the tiny leaks
Upvote 0
Which tends to fail after very few operations, hence the question about using different O rings, as I would rather keep it pressurised.Thus WHY fitted with an On/Off valve .... Don't store rifle with the action charged up
Upvote 0
ya..that little o-ring gets clippedWhich tends to fail after very few operations, hence the question about using different O rings, as I would rather keep it pressurised.
became very quick at replacing that one
works better with the air adapter
i believe you can also try break the edges off on the flow hole if you have a dremel tool, but i haven't tried that one
Upvote 0
Being design uses O-rings UNDER & FOR every seat under pressure ( Poppet, Both regulators and solenoid ) the issue with recession/deforming of o-rings is just going to happen faster.Which tends to fail after very few operations, hence the question about using different O rings, as I would rather keep it pressurised.
Upvote 0
Skout has used poly for 30+ years. Tom Kaye (Owner of Airgun Designs/Shoebox compressors) used poly in his Automag. The Automag was indestructible. Skout/Smart Parts was very close to Tom at one time, before they started making their own guns. They probably felt it was a good way to go.
In some ways they are more durable than buna but less forgiving.
I think the poly may help with 'stiction' issues but that is just my uneducated opinion.
In some ways they are more durable than buna but less forgiving.
I think the poly may help with 'stiction' issues but that is just my uneducated opinion.
Upvote 0
Skout needs to do both Buna N & Polyurethane O-rings. There is no doubt that poly is better in some applications…….AND there is even no less doubt that Buna N is better in a lot of applications. A PCP can utilize both in the same gun. That’s my .02.
Again, my opionion here; Skout used poly previously and they are not only accustomed to such seals but that’s what they had in paid for stock and available. Now, with PCPs please diversify your seal use portfolio
Again, my opionion here; Skout used poly previously and they are not only accustomed to such seals but that’s what they had in paid for stock and available. Now, with PCPs please diversify your seal use portfolio
Upvote 0