A few things you should know before starting out...PVC:
Always used pressure rated PVC. Never used DWV, which is unpressure rated PVC and can explode at such pressures. DWV may be cheaper or easier to find but it is not worth it. I live in New Zealand and pay 1300% more then you Americans do for pressure rated PVC, so just buy the proper stuff.
I made an article on how to identify pressure rated PVC here:http://www.spudfiles.com/spud_wiki/index.php?title=Identifying_Pressure_Rated_PVC
I'm sure most of you are familiar with 'Sch 40' PVC. The 'Sch' rating is not a pressure rating
. It is a thickness rating.
In NZ we use a different system but i'll convert it over for you.
You want to make this cannon with at least Sch 40 NSF-PW pressure rated PVC. Do not take this cannon over 120psi, it can take more but you don't want to push it. If you live in Australia or New Zealand you want to use at least PN12 rated PVC pipe and fittings.Metric/Imperial
Since I built this cannon with metric fittings, it may differ slightly in America, but it shouldn't be too much off. The only big difference is that in NZ and Australia, 40mm pressure rated PVC fits golfballs. In America you will have to find 1.5" SDR 21 PVC
. It may be a bit flimsy so you can sleeve it with 2" Sch 80 PVC. Or you can just buy it online from www.bcarms.com
I will convert all the units to imperial as well as metric. To help everyone out.Cost and Time
If you live in America this shouldn't cost more then $70-100USD. If you live elsewhere it could cost up to $300 NZD. This cannon took about a weekend to build for me, it will probably take you more. Be preapred to commit to this project.