What material make a best piston?

[AnotherSnappedLine]

Im debating my choice...it will be a spring loaded QEV so I need something light and quick(Epoxy). Im thinking of a 3/4-1" valve to a 1/2" barrel. me design will be sort of like this: [/url]

[daniele tn]

Has anyone tried to cast a piston out of this stuff? http://www.instructables.com/id/Making- ... dly-Plast/

It look like it could be solid and lightweight.

[AnotherSnappedLine]

I looks pretty flimsy. I wouldn't take it above 50PSI

[saefroch]

Bioplastics info
Other plastics info
UHMWPE is usually considered the best material for a solid piston.

[nadjatee1996]

Bioplastics info
Other plastics info
UHMWPE is usually considered the best material for a solid piston.

I'm going to use it as a filler

[clemsonguy1125]

I've tried the bio plastic, be molded as it shrinks when it dries and can only be rolled out in flat sheets if you want it to end in the same shape

[r00kie]

I've read about Bondo, epoxy, and hot glue to make a piston; which is the best substance?

Don't use hot glue if you have a warm climate, I found out the hard way that they tend to expand and become far less efficient, sometimes even jamming completely.
Epoxy is great, I can't fault it for a piston, it's highly mouldable, and sandable once it dries. JSR has a good thread somewhere showing epoxy pistons with different cores to reduce weight.