Easy Piston

Atlantis · Mon Oct 23, 2006 9:01 pm

I found a way to make a piston that will work for any size pipe.

Push a grocery bag into the pipe, try and get the bag against the walls.
Fasten the bag into place.
Fill the bag with Silicone Rubber (Any filler should do, I just liked that it made it's own rubber face.)
Before it hardened I put a golfball inside it for no reason, later turned out to be useful, the rubber does not stick to the golfball and I was able to peel the piston off of around the ball, this made the piston hollow, the outside fits inside the pipe and the inside makes a sealing face.

The golf ball was not sunk all the way into the rubber, part of it was sticking out. You'd have to find a differnt ball for different size.

Basically a really simple molded piston that can be made to any size.

judgment_arms · Mon Oct 23, 2006 9:04 pm

Could you use Duck tape?

Slugfoot · Mon Oct 23, 2006 9:56 pm

Hmmmm.......sounds like a plan.

Have you tried it out yet? I'd be concerned about it being a bit soft and getting blown/sucked through the barrel. Is there a harder setting silicon stuff?

Just a thought.......It occurs to me that one of those hard rubber "bouncy balls" of the right size with a spring behind it to push it up against the outlet port/barrel may make a good piston. Has anyone here tried this?

Velocity · Mon Oct 23, 2006 9:58 pm

That is an ok idea for a piston, but it will not have a perfect size fitting, and rubber pistons generally have a lot of friction. But a bit of vaseline should solve the friction issue.

A similar way to do this is to cut a small length of the pipe, and stick a piece of paper under it. Cover the sides in cooking spray. Fill with something (hot glue, silicone rubber, etc). Take out, and there you go: piston

SpudStuff · Mon Oct 23, 2006 11:23 pm

Yah I atempted to make a 2" one. I used expanding foam. It cracked the pipe?

Atlantis · Tue Oct 24, 2006 1:45 pm

I never removed the plastic bag, it is stuck to the rubber, the sides and one end are covered in grocery bag plastic, the other end is hollow, the sealing face is IN the piston in the back of it. It slides pretty easily.

Slugfoot · Tue Oct 24, 2006 4:23 pm

So in effect the piston sits around the barrel?.......ingenious.

Atlantis · Tue Oct 24, 2006 5:17 pm

Yep, even though that happened completely by fluke chance. I had intended the golf ball to be for weight, then I noticed I could'nt get the bag off and the golf ball came out, did'nt really have a choice, worked out nicely though. This helps too, you don't need any extra space for the piston to move.

Benny · Tue Oct 24, 2006 5:27 pm

Could you use Duck tape?

you could use anything that makes the pipe leakproof temporarily.

Just a thought.......It occurs to me that one of those hard rubber "bouncy balls" of the right size with a spring behind it to push it up against the outlet port/barrel may make a good piston. Has anyone here tried this?

Demon Did.

Atlantis: i like that idea, because i have like a 5 kg container of it.

Atlantis · Tue Oct 24, 2006 8:50 pm

Cool, how much did that big of a bucket cost? I'll probably stick to tubes but all...corection...A LOT of power to ya, that much rubber, wow. Is somebody in your house a plumber?