Missinformed at its finest.
IF THAT IS ABS YOU NEED TO TRASH THAT GUN AND GO MAKE IT OUT OF SCHEDULE 40 (or greater) PRESSURE TESTED PIPE.
TRUST ME on that one.
Hairspray is rather rich in fules. A 1-2 second shot should be about right for your combustion chamber.
Also, for a better gun you need to learn about propane injection and fule adjitators. small, brushless fans work, as do chains. Propane is cleaner, leaves no residue, is more powerful, and IIRC cheaper in the long run. Also a 1: 1.2 - 1:1.5 combustion chamebr to barle volume is optimal for most gasous fules you could use.
If you want me to tell you how to make a propane injection system I will. You will need to learn about the combined gas law and have a little bit of innovation as each gun will be different.
If you are really interested in kickass potato fun I will give you some insight on hybrids and more reliable ignition systems. Just a little spark for you to catch the fever...larger hybrids have been known to brake the sound barrier.//content.invisioncic.com/y282845/emoticons/up2something.gif.dd110ecf3ae4b76050d87598f2f8de7c.gif