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piston sealing
Posted: Tue Sep 24, 2013 3:28 pm
by dart guy
has anyone found a good sorce of rubber that is good enough for a qev
Posted: Tue Sep 24, 2013 3:54 pm
by MrCrowley
We're gonna need a bit more information than that, dart guy.
What size QEV are we talking about? Do you mean a piston (shuttle) or diaphragm QEV? Do you want to replace the shuttle/diaphragm in a store-bought QEV or are you planning on making your own?
I imagine any rubber of reasonable thickness and flexibility would do, it depends if it needs to be a diaphragm or shuttle piston.
I've successfully used this crappy little suction cup thingsas a valve replacement for a 1/4" QEV:
The edges fold over each other backwards when inserted in the valve body, which keeps the rubber body stationary. Then the middle bit can simply move back and forth like a diaphragm valve. Just an example to demonstrate that you may as well try any rubber you get your hands on but whether it works or not will depend on it's exact purpose.
Posted: Tue Sep 24, 2013 3:59 pm
by dart guy
l was thinking of the way that wyz(whatever the heck the rest is) made that is mostly soft i so far gave made a golfball pistion but the thin rubber band under the bike inner tube but it doesnt glue well with epoxy and it doesnt seal.
Posted: Tue Sep 24, 2013 4:14 pm
by MrCrowley
dart guy wrote:l was thinking of the way that wyz(whatever the heck the rest is) made that is mostly soft i so far gave made a golfball pistion but the thin rubber band under the bike inner tube but it doesnt glue well with epoxy and it doesnt seal.
Strangely enough, I think that's easier to understand if you read it backwards
You still didn't answer any of my questions. I have zero idea what your intended use for this rubber is.
Posted: Tue Sep 24, 2013 5:20 pm
by Talk
you can get these kind of piston seals from some shop which sell ball bearings and similar stuff like that
Posted: Tue Sep 24, 2013 9:01 pm
by Gun Freak
Try ripping apart a printer. I've found some really nice rubber parts suitable for pistons on their own in there.
Posted: Wed Sep 25, 2013 1:35 am
by ToasT
Shoes.
You can find them everywhere and they often contain plenty of rubber. Play around with different glues until you find a combination that works.
Posted: Wed Sep 25, 2013 3:51 am
by oneocim
you can use the rubber used for this aquarium air-pump to sit. I use them for mine.
Posted: Wed Sep 25, 2013 2:58 pm
by dart guy
Sorry mr crowly but ive been a little rushed and my computer is screwy
also i need it to be cheap and easy and i dont have any broken printers or aquarim filters and i need my like 2 pairs of shoes

Posted: Wed Sep 25, 2013 4:03 pm
by PeteS
Lowes sells sheet rubber that I have crazy glued or bolted to piston faces. It has worked well for me in calibers from .5" to 2". The 1/8" did not work as well with my pen gun, probably due to the higher pressures and smaller surface area for the seal. I went to a solid teflon piston so I did not try the 1/16" on the pen gun.
1/16" 6"x6"
http://www.lowes.com/pd_31448-143-PP255 ... lumb%20Pak
1/8" 6"x6"
http://www.lowes.com/pd_31446-143-PP255 ... lumb%20Pak
Posted: Wed Sep 25, 2013 4:10 pm
by dart guy
i havent been able to get to lowes in a while and i also want my first gun to be cheap so that i figure out the basics
Posted: Wed Sep 25, 2013 5:01 pm
by Gun Freak
That rubber is less than 2 dollars... Are you serious? And you'll use it multiple times... Go to a hardware store and buy a neoprene washer for 35 cents then. You're gonna have to buy something eventually... You're not gonna make a piston valve gun with toothpicks and straws and hot glue.
Posted: Wed Sep 25, 2013 5:59 pm
by dart guy
gunfreak i may have left out the detail that i am fourteen and they ( the goverment) dont like kids driving a dirtbike on the road(im like23 miles from a lowes or home depot
Posted: Wed Sep 25, 2013 7:23 pm
by Zeus
When I joined I was 15 and 30 miles from any stores, I still built a few things. You can buy pipe fittings from UXCell cheaply if you've no transport.
Posted: Wed Sep 25, 2013 7:48 pm
by Gun Freak
dart guy wrote:gunfreak i may have left out the detail that i am fourteen and they ( the goverment) dont like kids driving a dirtbike on the road(im like23 miles from a lowes or home depot
So... You don't have a parent or guardian or friend that can drive either?
At this rate I wouldn't be surprised if you expected us to give you not only advice but free parts too
