Finally, a good pvc! (and chamber help)

[elad311]

Today i went to a shop..
and i saw a between the thin PVC (as usual..),
a black pvc(i think it was a pvc), and i couldn't bend it..
so i finally found a good material for a combustion..
and because i don't have pvc glue in my country, i'll use screws. 8)
so now.. should i buy a 25" 4" diameter chamber..
or a 25" 3" chamber?
(Because, i don't know what goes better with a tennis ball and golf ball barrels.

and one more thing, are over/under cannons making the
launcher weaker?

[TurboSuper]

I think the black stuff is ABS, good stuff for combustions.

And no, an over-under configuration won't affect performance too much. You add a bit of dead space with the elbows, but nothing significant.

[starman]

Please check again for the cement. Both PVC and ABS use a special cement to attach pipe to adapters, couplers, clean-outs, etc. Screw connections are fine to adapt to other threaded materials but the pipe doesn't have threads and uses cement to assemble.

Having to use screws to connect all of your adapters and pipe together makes no sense whatsoever. What do you think the plumbers use? Yes, primer and cement. Ask the dealer where you bought the ABS pipe for the ABS cement.

[psycix]

Hmm, does it read anything?
Could you post a picture?

[jackssmirkingrevenge]

If you can't find proper cement, a good roughening up with sandpaper followed by some quality epoxy is a more than adequate substitute, much better than screws.

[elad311]

Hmm, does it read anything?
Could you post a picture?

yes, here's the pipe:
(this is an internet picture, not my pipe, but this
is exactly the pipe i have, but mine is more black.)

[psycix]

Hmm cant really tell from that pic.
Should be okay for a comby.

Whats the wall thickness?