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Pistons

Posted: Mon Jun 26, 2006 9:58 pm
by 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?

Posted: Mon Jun 26, 2006 10:06 pm
by carlbelcher
It depends, but I'm afraid it might shatter.

Posted: Mon Jun 26, 2006 10:20 pm
by ProfessorAmadeus
even if you use a good bumper?

Posted: Mon Jun 26, 2006 10:30 pm
by 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.

Posted: Mon Jun 26, 2006 11:20 pm
by Shrimphead
You could try and fill it with something to try and help stop it from shattering, I don't know.

Posted: Tue Jun 27, 2006 6:46 am
by 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.

Posted: Tue Jun 27, 2006 10:04 pm
by 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.

Posted: Tue Jun 27, 2006 10:28 pm
by 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.

Posted: Wed Jun 28, 2006 9:09 am
by 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...

Posted: Wed Jun 28, 2006 10:19 am
by ProfessorAmadeus
i was going to fill it with bondo. That sould work right?

Posted: Wed Jun 28, 2006 10:28 am
by frogy
Anything for weight\structure will work, bondo's fine...

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

Posted: Wed Jun 28, 2006 2:48 pm
by 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. :(

Posted: Wed Jun 28, 2006 10:18 pm
by 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

Posted: Thu Jun 29, 2006 6:48 am
by 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.

Posted: Thu Jun 29, 2006 9:58 am
by 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.