SpudFiles

im new to making combustion guns. i have make a big pneumatic, mini pneumatic, and a mini combustion. i was wondering if the combustion chamber has to be pressure rated as it isnt holding pressure, just directing it. i was also wondering whats the point of removing the sparker from the bbq ligter. does the open flame decrease power or something?

depends on if its and advanced combusion on not if you are using simple spray n pray combustion press rated pipe is not nesscacary but if you are using meterd propane in an advanced i would reccommend it. i dont understad the last part though

Open flame (in theory) burns up oxygen needed to ignite everything else. The chamber usually will be pressure rated unless the pipe says JUST DWV. Usually there is a rating for it.

i meant that everyone posts tutorials to get the sparker out of the bbq lighter. whats wrong with just as is. thanks for help with pressure rating question.

i've changed my mind about igniter. im gonna use a upgraded fly swatter. for chamber i was going to use a packaging tube from a giant kite i got years ago. will this be ok for just a spray-and-pray combustion?(its at least 3times as thick as a fizzy drinks bottle thats pressure rated to ~160psi)

probably for that many people have built garbage cannons out of card board

Bro you should really use PVC and build the cannon properly if your going to use a fly swatter ignition and all that! Just my 2 cents.

gwoloshyn wrote:Bro you should really use PVC and build the cannon properly if your going to use a fly swatter ignition and all that! Just my 2 cents.

Why so when the damn thing blows up on him he can get shrapnel all in his ass. For a cumbustion use ABS, tardo. the ignition has jack $hit to do with the power created. just a faster more reliable metheod of ignition. the fuel used on the other hand has EVERYTHING to do with the power created. as far as the reduction between the chamber and the barrel that is the only thing i see wrong do not use a reducer because they are weak. use a couple bushing setup, much stronger.

Grib-Take it easy. Using advanced combustion, it produces about 20psi more than a standard hair spray. There are plenty of advanced combustion cannons that use abs and dwv.

For a spray'n'pray, you can use pretty much anything with some integrity, as long as it isn't cell core. ABS is ideal, and cheap, but they have been made out of lots of things.

Sorry I just get all riled up when people say you have to use pressure rated for a combustion mine advanced combustion is all cell core but for the fittings because they are the weakest point i use rated fittings and coupler/bushing setups for reducers.

DYI wrote:For a spray'n'pray, you can use pretty much anything with some integrity, as long as it isn't cell core. ABS is ideal, and cheap, but they have been made out of lots of things.

Grib, didn't you just say yours was cell core? All it is really, is lamenated foam (along the lines of that).

so.... would 2 layers of 3X thicker than fizzy drink bottle make out of more or less the same stuff as drink bottle hold and not set me alight. coz in the uk you cant get pvc above 40mm without special order and 6m lenghts

you can use a lot of stuff to make a spray and pray, but the threads are usually the weakest part
no they don't need to be made from pressure fittings but it's good to avoid cellcore, I'm sure sch40 dwv pvc fittings on a properly constructed cannon won't break. if you decide to use some ghetto chamber like a peanunt butter jar, always take caution of that cap blowing off,

(its at least 3times as thick as a fizzy drinks bottle thats pressure rated to ~160psi)

that mentality will get you killed,
your talking about cardboard right, only 3times thicker, no, but just don't hold it and the worse should be some minor burns

if its plastic then heck no because it sounds like a brittle plastic tube with some compression strength and no tension strength for holding the chamber together during the combustion, the result will probably result in a fragmentation bomb

its flexble and you can squeeze it with a bit of pressure. its like from a coke bottle