starting fluid

[nibbler125]

! know some people here have tryed to use starting fluid in there cannons with not so good results. the problum is that the stuff is soo hevely concentraded. the way i got it workin is i sprayed some into the cap on my cannon and screwed it in. and waited 30 seconds for it to evaporate into the chamber (a chamber fan would help) and it shoots with some pretty high ammount of power close to propane.

[c11man]

by starting fluid do you mean the stuff that you spray in engines to get them to start?

if it is my friend has been using if just like hairspray for several years now.

the trick is to take of the top nozzle thing and put a hairspray nozzle on it. this creates a much finner mist and works very well. you just have to be careful not to spray the ignitor other wise it just shorts and doesnt spark

his cannon has a 18inch by 4inch chamber with no fan or multiple ignition just a bbq lighter, and 3 layer foil burst disks and it works great shooting gbs. we only have to use a quick 1 second spray for the most power. if we use too much (sometimes on perpose without burst disks) we get severly decreased power but we do get a 4 foot flame.

[grock]

i think he means starter fluid, like the stuff you get from the camping section to pour on your fire, and that stuff does work, like crazy. getting the mix right is tricky though

[jimmy101]

Hmm, "starting fluid" = BBQ starter fluid (basically kerosine?) or automotive starter spray (often propane + dimethyl ether).

For hydrocarbon type liquids take a look at this page on liquid fuels. It'll give you an idea of how much of a particular fuel should be used for a given chamber size.

In general it takes about 2 "drops" of most hydrocarbon fuels per 100in³ of chamber volume. "Drops" are not a very precise measure and it is difficult to measure drops with high vapor pressure fuels (kerosene, gasoline, alcohols...). A "typical" drop is about 1/12 of a ml.

Even if you don't use a syringe or a dropper to measure the fairly small volume of fuel needed it is handy to have a rough idea of about how much fuel it should take to get a stoichiometric mixture.