Firing problem

[Anon]

Ok so my first combustions been working fine until today. I finally fixed my ignition mount and got the gun in working order. Now I slapped on my 8 foot barrel and filled the chamber with propane using the timed amount that always worked before. I got nothing not even a small noise. So I aired it out and checked my spark and its more than big enough to ignite the propane. The weather was sunny with a bit of wind when I fired it. So what do you all think the problem is?

--edit--
Yes I tried different bottles one is brand new and the other was used a bit.

[Dom]

Leak?

[MrCrowley]

was the propane getting to the chamber?have you used the brand of propane before and it worked?did you put too much in?have you tried using hairspray just to se if it works?

[plumpthumb]

I agree with Dom; the only time I ever had the same it turned out to be a leak in my connections from tank to gun. I checked it out back at home and found my connection had loosened and the propane, at pressure was going into the thin air. New connection type and a well tightened clamp and no more problem.

[Anon]

Around my connections i used a gasket sealer when I made the cannon to ensure it to be air tight even with the glue and primer. It is possible that thier is a leak I am not seeing and about the propane brand its burnz-o-matic i think dont have the bottle near me.

[MrCrowley]

well have you used it before?does it light easily?when filling your chamber with propane pour water of the fittings and if it bubbles its leaking.

[sgort87]

First off, you use soap water. Second, that trick doesn't work for a combustion because pressure is not trapped in the chamber like a pneumatic.

My guess is that you are not using the correct amount of propane. try using less.

Your barrel probably has a lot to do with it. Are you making sure to have something in the breech end of the barrel when firing?

[MrCrowley]

i thought you could do it on the propane fittings not the chamber like if you let some propane in and blocked of the chamber there should be propane pressurized(sp?) in the fittings?

[Anon]

Ok I havent had much time to trouble shoot the gun but I will answer some of the questions posed.

Yes the barrel is loaded with something the same diameter as the barrel.
I have tried 10, 20, 30, 40, 50, 60, 70 seconds of propane using my torch head and it works best around 60-70 seconds usally but wont work with any of those times.
Only thing I can think of is I got a leak somewhere in the fittings.

[noname]

60-70 seconds!?!?!?!? How big is this thing?

[SpudStuff]

try to 1-5 seconds. Remember you need very little.

[MrCrowley]

you must have one helluva mothertrucker leak if your putting 60-70sec in.

[Anon]

My reason for using so much time is the psi my torch head is at (unsure of exact number) is kind of low. But the chamber is 353.858 cubic inches. I am guessing its a small leak somewheres on the front end of my chamber.

[WOW!!]

Since it sounds like the propane is not metered you should meter it. For that you need 7.5'' of 1/2 pipe.(steel) and 2 1/2'' ball valves. And then a 1/2" street elbow going in to your chamber. What do you have on the back of the chamber? And is the barrel glued or threaded?

[Anon]

Ok the barrel is threaded and I have a clean out plug on the back of my chamber. I was going to put a metering system on it but decided not to since my cannon funds are limited.