Pistons

[ProfessorAmadeus]

YEAH!!! i just found a perfect fit for a 2 in coaxile pistons but dont know if it will work. its an old elmers ruber cement container. Can you use glass for a piston?

[carlbelcher]

It depends, but I'm afraid it might shatter.

[ProfessorAmadeus]

even if you use a good bumper?

[carlbelcher]

That’s hard to say. I think it might just work. Glass is just kind of unpredictable, you might fire it 100 times with no problem and then it would just shatter, or it might just break on the first shot, or it could work just fine. You just don't know with something that brittle. I would just say go for it all you have to lose is an old glue jar anyway.

[Shrimphead]

You could try and fill it with something to try and help stop it from shattering, I don't know.

[mark.f]

If you're making a 2" coaxial piston, maybe try using a caulk gun as a piston? I've only shot one of these once before, but it fit pretty good inside 2" SCH-40 NSF-pw. If you were to add O-ring grooves and some O-rings on the piston, (which I recommend, for more predictable equalization control), you would get an even better, airtight fit. Although it would need to be lubricated, with this method you could even install a check valve for equalization, allowing you to fire your piston with even a measely 5 cent blowgun.

[noname]

If you actually do use the glue jar, pad the back with sponges or something that absorbs energy but if I were you I just wouldn't use it. Pistons are annoying aren't they. I love my diaphragms. Try getting a peice of pipe that goes inside 2", some gaskets, some neoprene, a long bolt, and some nuts and you got yourself a piston that holds pressure.

[Atlantis]

I found a pill bottle that fit in 2" nicely, it's from a dog medication bottle, so it's pretty big. Caulk tubes would work also, you can keep them filled or empty it out part or all the way, your choice.

[frogy]

I'd fill it will Durhams water putty for weight\durabity...

I think if it had a solid inside and it's solid glass seal on the outside it wouldn't shatter, just make sure you have padding on the glass bottom...

[ProfessorAmadeus]

i was going to fill it with bondo. That sould work right?

[frogy]

Anything for weight\structure will work, bondo's fine...

I wonder why anyone hasn't make an entire piston out of bondo....

[noname]

I was thinking about doing it but I use my friends huge can of it when he left it at my house. He took it back now though.

[pneumaticman]

well if you're afraid that it will break i have a very simple solution. just take duct tape and wrap it around the glass so if it breaks i wont go every where kinda like shatter proof

[carlbelcher]

If it does break just dump out the broken glass and go back to the drawing board. Not much to loose. It could just be a really easy solution to a common problem.

[noname]

Except that when it broke it would shoot glass out of your barrel everywhere. Just get a piece of 2", set it on the ground and fill it with bondo. When the bondo's dry you have a perfect rock hard piston.