I was able to find most of what I needed at Lowe’s.  I bought all the PVC there, a PSI gauge, and a hacksaw.  I ended up having to go to Ace Hardware to get the Schrader valve.  One of the guys that works at Ace Hardware instantly knew what I was building when I told him I was attaching the valve to PVC.  It turns out he has built a few of these himself.  He advised me to use caulking to seal up the valve and PSI gauge to the PVC.

Once I returned home to my apartment I laid out all the pieces to make sure I hadn’t forgotten anything.  It was at this time that I had realized the 3″ Sch40 PVC I had purchased to function as the pressure tank says right on the side of it “FOR NONPRESSURE USE ONLY”.  Great.  It turns out this Lowe’s doesn’t carry PVC pressure pipe in any sizes over 2″.  I also tried the nearest Home Depot with no success.  I will be stopping by a bigger Home Depot today to try and find some.  Once I have the pipe, I can start chopping, drilling, and gluing everything into place.  I’m hoping to have this thing ready by Sunday so I can launch some potatoes into orbit.

I’m adding a page for this to the Works in Progress section.  I’m also adding a page to the ideas section for a coil gun.  While doing research for the air cannon I found many resources on building a small coil gun out of used disposable cameras.  I’ll most likely be stopping by a CVS soon to try and score some.  There are actually several ideas I have for the disposable cameras but the coil gun sounds the most intriguing to me right now.  I’ll be posting updates as things roll along.