8 replies to this topic

[0bs01337]

When making an air tank is plumbers goop alone strong enough to hold on the end caps, or do I need to go through and use purple primer?

I ran a search for air tank construction, but didn't find anything.

[GeneralPrimevil]

For PVC? Use primer and cement if pressures are over 40 psi. Otherwise, use brake cleaner and cement for lower pressures. Plumber's Goop I don't think would work to well; however, I don't have any experience with Plumber's Goop. I was under the impression it was a sealant, not an adhesion agent.

[fobpawwor]

The best all around sealant is probably exposy. From experience, everything thing I made, had epoxy glue used on it.

[davidbowie]

Even if you're using less than 40 psi, it's not a hassle to use primer and cement. It's better to be safe than sorry. It's not like primer costs much anyway.

[GeneralPrimevil]

Brake cleaner is free for me and works the same as PVC cleaner. It also doubles as a propellant for certain...wrong forum.

Yeah, for what it's worth, just use primer if you have it. If you don't, you'll need it later so pick some up now.

Is "exposy" a brand of epoxy or something? All I know is that if you want your fingers to have to be surgically seperated, glue 'em together with an epoxy for use with either plastic or metal.

[ShadowSniper]

I would definitely recommend using the purple primer along with the cement. Even if your not getting high pressures its still gives you a reassurance. I've had an only cemented gun explode at 100 PSI...not cool. Also adding the primer makes it less likely to leak. All in all I'd say the primer is worth it.

Edited by ShadowSniper, 28 March 2006 - 08:16 PM.

[davidbowie]

Why use goop at all? Use primer and PVC cement. I'm pretty sure the cement is cheaper than goop. It seems like you're going out of your way to produce a weaker joint. It's simple, easy, and reliable to use primer and cement, and you can save your goop for things you need it for.

[0bs01337]

Thanks for the replies. I'll pick up some primer and cement soon. Does anyone know of a calculator or formula for the expected range loss on each shot when using two tanks? Or reccomended ratios between the tank sizes? Don't know if there's a name for it, but it's the set up explained below.

Set up
Big tank-valve-little tank-trigger valve- barrel

Firing
open first valve to equalize pressure, close first valve, fire

[crackshot]

^^^That sounds a lot like the Walloper (3DBBQ's favorite/newest homemade). I wouldn't expect too much air loss from it, if you do a tight valve assembly.
-cs