What material make a best piston?

[AnotherSnappedLine]

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

[chinnerz]

what pressures are you planning on using it at??

[clemsonguy1125]

I personally like rubber stoppers with epoxy cat around them for my small boar cannons and for large cannons steel washers with a coupler in between with a sealing gave bolted on.

[jackssmirkingrevenge]

Epoxy FTW!

For small projects likethis I usually cut the piston out of thick rubber sheet.

my small boar cannons

Sorry, couldn't resist!

[Gaderelguitarist]

Epoxy will last the longest out of those choices.

Several people turn their pistons on lathes or drill presses from plastic stock. HDPE, UHMWPE, Polyamide, PVC, Nylon, etc etc.

I've made a wooden piston (big surprise) for a small wild boar cannon.

JSR, I don't know if I'm laughing more at the edit, or at that hunched over kid's facial expression.

[Gun Freak]

Sorry, couldn't resist!

That just made my day lol!!!

@Gaderelguitarist- It's quite the jizz face huh?

[clemsonguy1125]

Lol. my ipod changed it.

[Gaderelguitarist]

It's quite the jizz face huh?

It's as if Igor threw the main switch and doctor frankenstein lost control all over his hump.

And thats about as off topic as this should get

[jackssmirkingrevenge]

What if I told you that was me 20 years ago?

lol no seriously, that was a random pic lifted from here, hope the poor child doesn't suffer the same fate as scumbag steve

[Labtecpower]

...or the angry german kid!

[youtube][/youtube]

I'm sure most of you know him

I made the piston for my copper gun out of nylon, as the previous one broke down every few shots.

The cannon i'm building now uses a PVC piston.

Both are made on a lathe.

[saefroch]

UHMWPE can be machined using a drill press, and if you round off one end, you can slowly force it into the part you want it to seal to and melt it with the friction while it's still spinning for a perfect fit, and probably a seal.

[Labtecpower]

Just turn it down to the right diameter. I got a 0,01 mm fit on a lthe

I had to make it even smaller, because it didn't slide smooth. just keep 0,05 mm of space.

0,01 mm is 0,000393700787 inch by the way. google FTW!

[Gaderelguitarist]

...or the angry german kid!

Is that a 2 girls one cup video reaction???

I'm a little concerned that the author of the post hasn't responded to any of these suggestions.

[AnotherSnappedLine]

No, Im here...just had an all day wrestling tourney so Im finally getting on the computer. Im pretty confident on using epoxy.

Thanks for the feedback!

[mark.f]

I guess the most pertinent question would be: what size of piston are you making?

Epoxy or bits of metal hardware with some sheet rubber are great for smaller pistons. For larger (1-1/2"+) pistons, I usually make them out of PVC (just use a sufficient bumper).