SpudFiles

All you need is a can of suave 24 hour protection deodorant. (In a tall, light blue can.) Take the cap. Notice how well it fits in a 2" tee. (At least for PW Eagle brand PVC...) I filled it with small styrofoam blocks and hot glue, but I only used the blocks because I didn't have a lot of hot glue. Result: a cheap, easy, durable piston that performs great! (I just shot it today, and it blew me away how easy it was for the kind of results I got!) If I find time, I'll post pics, but it's nearly midnight here, and it's a school night...

i think someone has already made a gun that uses an old deodrant can.

I am fairly certain he is talking about the cap of the can. Reguardless, please post some pictures so that we may be able to see.