SpudFiles

hey guys 8)
after playing with my first cannon, i'm ready to make a piston!
so, i got everything for it except a neoprene sheet.
where can i get one besides the internet?

thanks

There's lots of options, what size is your chamber?

If you square off your barrel end and piston face sufficiently, you could try tire patches. Available everywhere and even come with the glue (repair kit).

Might not be neoprene, but it will work.

Bicycle inner tube is also a reasonable source, though you might have to layer it.

its a 2" chamber coaxial with a 1" barrel.

how many layers would it take for a bike tire?
i tried the tires and they try to curve up

they wont curve up if you use a washer to hold it down.
And you can get neophrene from Mcmaster

if you can get a busted high pressure regulator for gass bottles it is a diagramph in them and they are pretty much the best you can get. i use one on my copper marble gun to seal against a 1" copper tube and i have shot at least 400 shots of it and you barely can see it is used
and it is armed really well as well

bigbob12345 wrote:they wont curve up if you use a washer to hold it down.

Use a large washer that is slightly smaller than the ID of the barrel, this will keep the innertube down so that it doesn't fly into the barrel. Also, put grease inbetween each layer of innertube, it works much better for some reason.

On my last piston i used a large rubber washer sold at lowes. I then used a smaller metal washer to hold it in place. I was very pleased with it, never had a leak problem, sealed up every time.

I'm not sure if ace hardware is a national chain or not, but they sell neoprene fender washers that get pretty large. I bought one for a 3/4 inch piston that seals against a 1/2 inch barrel and the washer was big enough to cut a solid circle of rubber from the side of it. Also I havn't tried anything else yet but I heard good things about BARGE contact cement so I tried it, and it has held very well. One more little thing, make sure that the back end of the barrel where the piston seats against is cut very square and sanded super smooth. If you round the edges of it a bit I think it will help your sealing face from getting messed up. I have shot mine a lot and the neoprene still looks new.

Good luck, Lock

You can get rubber sheeting from any DECENT hardware store, from thin to up to 1/2" thick. Whether I know if Home Depot or Lowes falls into that category... I haven't really checked there yet.

EDIT:

Also, put grease inbetween each layer of innertube, it works much better for some reason.

This would prevent chafing of the rubber near where the sealing surface presses, so grease is a good idea if you're layering. That, or just use rubber cement to glue each layer together.