Metal water bottle thread size?

[NatoHub]

Do most metal water bottles have a common thread size for the cap (for use as an air chamber)? If so, what is it?

I'm looking to make something similar to this:
http://www.spudfiles.com/forums/viewtopic.php?t=15091&

[VH_man]

If you look, I beleive that tank was JB-welded on.

Try the threads used on garden hoses. At the paintball place i was at last, I could thread it onto the hose spigot....... Sending me on a great way to get the dents out of the dang things.

[brplatz]

Most likely it is a proprietary thread.
I used a old fire extinguisher bottle and it needed to be J-B Welded on.

[NatoHub]

I've never messed with QEV's or homemade piston valves (I've made a modded sprinkler), but could I basically make the above cannon with a QEV replacing his homemade valve? Seems like it should work, but I want to know if I'm right before buying a QEV online.

Thanks

[NatoHub]

Sorry to double post, but could anyone give me a quick answer? It's all I need to know to start buying parts. Thanks!

[MrCrowley]

could I basically make the above cannon with a QEV replacing his homemade valve?

Yes.

[mark.f]

They are 3/4" Garden hose threads, I believe. Just buy an adapter to NPT for around 5 bucks.

EDIT: Yup.