Piston Orings

[C Mellon]

OK I see a lot of things written on this. This is waht I know. Viton is the best material for a piston. It's good for most lubes, & is rated for 369 degrees. Urethane is one of the worst for a pumper. It is only rated for 200 degrees. You do not need a 90 duro oring to get the power from a pump. As for that matter I think they just plain suck. When I tested them in my gun. If it snagged on anything it tore a chunk out. I went thur 3 orings before I got one in the gun. They don't make anymore power, & if you have to be so carefull with them they just aren't worth the time.
Now for part two. I have had the same orings in one of my guns that I shoot almost everyday for more than 2 years. It has lost maybe 10-15fps. I think if I clean the valve I'd get that back. If used properly an oring rides on a film of lube & never touches the the tube. That's in a perfect world I know. However as far as wairing one out I did a little test when I started making pistons. I cut three different piston grooves. One .450", one .445" (the correct size), & one .435". The tight one.450 was super hard to pump, but didn't make any more power than the correct size. I had to drown it in oil to keep it moving. The surprise was the really loose one .435" made the same power as the correct size as long as I kept it oiled.
One last word I hate it when I hear people saying what junk these guns are. They cost $50, we push them way beyond what they are supposed to do, & they do it pretty well. Take your family car to the 1/4 mile & run it all day. Let me know what you got left when the sun goes down.   

[quickster47 †]

Great post Mr. Mellon.  Lots of good information and hopefully will dispel some of those nasty rumors about o-rings.

So, why do you think it is that some really push the 90 duro o-ring?

Carl

[1377x]

thanks for posting!
everything makes sense.my local air gunsmith basically says the same thing hard o-rings are not needed
i dont think we are looking for more power from an o-ring just longevity.lubrication is the most important part.
i am curious as to why you think cleaning the valve would get the lost fps back i kind of have a clue

[C Mellon]

The reason we need 90 duro orings is because we are AMERICANS. If two aspin are good, 4 must be better. The other reason they push them is jut because people want them, & they get $5 for 2-3 orings. Anything will last longer if you use it as intended. If you are going to pump your gun 15 times. pump 7-8, & give it a little break to cool off. Then finish. You won't build as much heat, & you'll get a better charge in the valve. My tires last 50,000 miles. My buddy lies to go fast. His last 15,000.
   

[NorthStaR]

One last word I hate it when I hear people saying what junk these guns are. They cost $50, we push them way beyond
what they are supposed to do, & they do it pretty well.

This is something most people seem to forget and a very valid point indeed. 

Everything has a limit. Everything.

[1377x]

mr.mellon,
i now see why you said cleaning your valve gets the fps back
cleaned my valve it is now shooting better than before
at first it was getting 500fps per 10 pumps and 584fps at 20x
after cleaning it is now 530fps at 10x 8.9fpe  and 596fps at 15x 11+fpe
at 15 pumps there is air left in the valve

[quickster47 †]

at 15 pumps there is air left in the valve

Was working on a 1377 with air conservation in mind and had a similar problem after I installed a HDD.  Took care of that extra air by making myself a power adjuster and trimming the spring.  Now I can get rid of all the air even at 15 pumps.

Carl

[1377x]

i usually add a preload to my hammerspring in this case i didnt because i dont need the extra power
10-12 pumps is all i really need for my 10-20yd shooting

[AZAG]

mr.mellon,
i now see why you said cleaning your valve gets the fps back
cleaned my valve it is now shooting better than before
at first it was getting 500fps per 10 pumps and 584fps at 20x
after cleaning it is now 530fps at 10x 8.9fpe  and 596fps at 15x 11+fpe
at 15 pumps there is air left in the valve

How do you clean the valve? Or more importantly is there anything i shouldn't do when cleaning the valve.

[quickster47 †]

I just take my valve out, take it apart and then clean all the surfaces using WD-40.  WD-40 is actually a very good solvernt/cleaner as it tends to free up all the gunk.  And there are better solutions you can buy but all they do is cost more money and really don't clean any better.

The worst thing you will find in the valve is some corrosion and this is the hardest to clean.  Start with an old tooth brush with stiff bristles or some other type of brush with stiff bristles.  If it is deep then a soft wire brush or maybe even a brass wire brush.

When I'm through with that part I immerse everything in Palmolive dish washing liquid and scrub everything.  After that I take all the parts out and dry them off and the use compressed air to blow them off.  The next day I wipe everything down and then assemble the valve.

Others will do it different I'm sure.  This is just my way that works for me.

Carl

[AZAG]

Thanks

[Cross Pistol Packer]

We have one of those small ultra sonic cleaning baths,spot of washing up liquid in warm water cleans out valve a treat
then dry down with kitchen towel..
Ray.

[quickster47 †]

We have one of those small ultra sonic cleaning baths, spot of washing up liquid in warm water cleans out valve a treat
then dry down with kitchen towel..
Ray.

Now there is a good idea.        

I think my wife has one of those I bought her for cleaning her jewelery.  Thinking I might have to confiscate it and give it a try on one of my valves.

Carl

[AZAG]

We have one of those small ultra sonic cleaning baths,spot of washing up liquid in warm water cleans out valve a treat
then dry down with kitchen towel..
Ray.

Good to know.  I was planning on get one of those for cleaning PB cases, so now i have another excuse...er, I mean completely valid reason for getting one.

[JEBert]

I was planning on get one of those for cleaning PB cases

You have peanut butter cases?
Sorry, too many SLA's, (stupid little acronyms) my brain can't keep up.
Cheeers,
Jerry