what would be a good material to use for the piston

What would be a good material to use for a piston other than pvc rod that's too expensive. I was thinking along the lines of cast epoxy or shapelock. I need a material that's pretty cheap too.

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Kiteman9 years ago
What dimensions are you planning on making it?
bob the builder #1 (author)  Kiteman9 years ago
I was thinking a two inch, like a mauler valve.
You could try discs of plywood, bolted through the centre or epoxied. If weight is a problem, maybe replace the middle layers with expanded polystyrene?
bob the builder #1 (author)  Kiteman9 years ago
tHANKS FOR THE HELP BUT i'M TYING TO FIND SOME THING EASY TO USE THAT DOESN'T REQUIRE WATER PROOFING. P.S. MY CAPS LOCK IS STUCK ON.
You can buy "marine ply" that is already waterproof. PS. I noticed!
bob the builder #1 (author)  Kiteman8 years ago
sorry, I didn't want you to think I was yelling though.
Lftndbt9 years ago
Use a bolt, two washers, two nuts and a thick piece of rubber cut to size. Or a plumbing rubber washer if you can find one the same size. Sandwich the rubber washer between the two steel washers. Tighten with nuts. Lubricate the rubber washers and there's your piston..
Lftndbt Lftndbt9 years ago
Are you set on a piston setup? You could achieve similar results with a garden 9V irrigation valve. My last cannon ran through a "pop it" valve . It was a sand blaster handset..
bob the builder #1 (author)  Lftndbt9 years ago
YEAH I'M KIND OF SET ON A PISTON VALVE BUT THANKS FOR YOUR HELP ANYWAYS.
I'm working on a mini coaxial now 1.5 inch chamber and half inch barrel. instructable coming soon.
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