The only pressure rated schedule 80 PVC I could find here was one inch diameter, but it did come threaded at one end. This saved me a bundle because I didn't have to buy a separate size PVC pipe, reducer, threaded adapter, larger cap, primer or glue (this would bite me later). The PVC and a cheap grill ignitor were all I needed for some tests.
I couldn't afford the grill ignitor with the remote switch, so I hacked the button built into the built in AA 'flashlight like' battery holder. Removed the rubber button, attached two wires; positive to side spring to complete the circuit.
Screws with washers, locking washers, and nuts were drilled into opposite sides. My multimeter found both grounds and hot connections, so I doubled each together for extra spark. I had to adjust the gap inside between the screws to get a spark large enough (not all sparks can start a fire).
(Opps! Sorry it's fuzzy)
I made a make shift blast area against brick and cement, and a wire long enough so I could duck around the corner.
I ended up hating the hairspray. The residue is smelly and it leaves the barrel very sticky, which I thought could eventually lead to a jam and explosion. The residue also stays on fire, and ended up scorching the PVC. The worse part is that it was inconsistent and would not fire in my cheap set up most of the time. I tried a few experiments with butane, but it was still inconsistent. I had some foam rubber darts shoot out, but it all had a risky feeling to it. Getting it to work would require money for a larger back chamber.