North Coast Electric down on 8th & Lander sells that stuff! Yes, I work there. :)

Memo Memo. Befriend Ken.

Ken, you may be my new living legend!

I have fired an even more dangerous version a friend of mine built.

It was iron pipe and nine feet long, rifled inside. It fired tennis balls from a ridge top (edited) repair shed nearly half a mile onto main street of a small town (which shall remain nameless since the cops are still looking for the maker) into the valley below. We stood behind a cinder block wall with a heavy Plexiglas window to fire it.

It used acetylene for the propellant and fired with a spark plug and ignition relay and a long cord for the switch. This was not the first model as a previous model had left shrapnel embedded in the shed wall and was the reason for the new door as well as the blast shield.

If the gas was not carefully metered, it fired yellow confetti instead of tennis balls.

Spud guns are cool and teach kids some basic engineering concepts. However, there are long lists of accidents, some with pretty serious repercussions, usually for children. My nephew made two and then converted them to marshmallow guns.
Not the same bang for the buck, but still loads of fun.

If your car has a sunroof you can turn it into a hashbrowns tank.

You guys gonna shoot potatoes at off leash dogs? ;-)

If all else fails there's the plumbing supply place just off the intersection of Marginal and Highland Park Way.

3" is standard sewer pipe...home depot has everything you need

I work at the home depot and im fairly sure you can find most of these there..... But im just a cashier......

My son and I want to make a potato cannon from plans in the Backyard Ballistics book (check Square One). We are having no luck finding the right kind of pipe. Most hardware stores only carry PVC pipe and fittings up to 2".

We need:
14 inch length 3" SCH40 PVC pipe
3 to 2 inch diameter reducing bushing
3" coupling, one side smooth, one side threaded
3" threaded PVC end cap.

We have/can get all the other items we need. Anybody (plumbers?) know where I can secure these items to begin construction?

Thanks in advance!