Whats the deal with O-rings and wood?

[SpudUke5]

Ok, im crazy :banghead:

I have been working on my copper gun piston (after the hot glue one broke), in which has not been working for me.

So, instead of hot glue, i was trying wood. So i got a 1 inch dowel, and put a sealing face with a screw and a washer and viola!! Doesnt work

Why?

Because air is leaking past the piston and somehow out the barrel.

Next idea,

O-ring.

So i make an o ring grove, and put a o ring on, then put it in the gun. Ok now it seals, but no air is getting into the chamber. Whoops forgot the equalization hole. Ok i go through the whole process and put one in.

Then, i put it back in and pressurize. All the air is leaking out the barrel.

Why?

O, because the o ring is preventing my piston from moving it to seal the barrel.

So can someone help?

If i can get it to work, i will pray to the epoxy gods and create a shrine where i will cast my piston with loctite marine epoxy and then tommorow ill praise them for it will work!!!

Praise epoxy.

I shall start the church of epoxy, made of epoxy, with JSR

P.S. I also did hurt and cut myself (accidentally) from all of this which added to my frustration.

P.S.S. A quick answer will be so helpful because its night time here and i got work tomorrow and i want to shoot this today

[Darkside 6ix]

One word.......LUBE

[SpudUke5]

Did try that but didnt work. (already had lube)

More info.

It did slide up all the way with lube, but didnt seal. Maybe its not heavy enough?

The support for my sealing face is the wood itself, is that bad or should it be something else?

[Sticky_Tape]

It is leaking out the barrel pvc phyco is there anything to seal the sealling face to the wood like glue? (BTW I know there is a screw but is there anything else?)

[SpudUke5]

Well that shouldnt be necessary, all of my other piston cannons never used a glued sealing face and they work fine.

[Darkside 6ix]

hmm.....Try putting a washer behind the sealing face...adds a little weight and support. Maybe your problem is that it isnt that heavy. But taking advice from me is like taking candy from a stranger because im not that familiar with pistons

[brogdenlaxmiddie]

try a spring behind it with potentially a guide rod.....

[SpudUke5]

I dont think i need a spring because the compressed air does the same purpose as the spring and i dont know what you mean about a guide rod.

[noob of noobs]

For a good sealing face, I found these washers at Home Depot with neoprene sealed to one end. When screwed onto a piston with a screw, they work magnificently, although they might need a slight bending in order to accomodate a non-linear lip and piston.

If the piston isn't moving forward however, you might want to check the piston's allingment. On my current gun, the piston was crooked, and it wouldn't push the sealing face up against the lip correctly.

You could also consider:
-Guide rod to accurately place the piston on the sealing lip (No, I don't know how to do this)

-Longer piston for more linear/consistent movement toward the sealing lip

-A spring behind the piston to push the piston forward

-A higher powered airsource pushing the piston forward (On one of my guns, you have to pump like a monkey on meth in order to get the piston to seal, but it's smooth sailing from there)

-Rebuilding the piston? It's somehow worked for me.

-Softer sealing face



EDIT:
brogdenlaxmiddie: GYAAARRRR!!! YA BEAT ME!!!!

I'd still try a spring though if you can, because it doesn't look like the pressurized air is enough.
Can you somehow open up the valve after you've applied compressed air? If the piston isn't pushed up firmly against the lip, then at least you know that the sealing face isn't the primary problem

[SpudUke5]

I think ill go with rebuilding a piston.

Im gonna go cast a epoxy one right now so i can use it tomorrow

The good thing about casted pistons is that they have never failed me.

[JDP12]

yea i'd also go with epoxy.. and if you dont mind would you go quick reply to my thread about 4" piston? I slapped a couple questions i would like answers to if ya dont mind?

[Gippeto]

Pictures of the offending part(s) will go a long way toward ending idle speculation, and usher in a speedy resolution to your dilemma.

[hi]

i didnt read other replies, but maybe try more pressure... you could also just wrap it in duct tape. it wont be as tight.

[SpudUke5]

I tried duct tape but it wouldnt seal correctly.

Its all good now a piston is casting right now and im just gonna wait until its done. Then ill make a big bumper to take up volume and them i hope it works.

Then i go to my high pressure pump.

[MrCrowley]

Hmm weird, I tripple o-ringed a wooden dowel once and still got air to leak past the sides. Baffled me, it was one helluva fit.