SpudFiles

im guessing around 90 psi(for regular foil) ...but you guys would know better....or the burst pressure for paper.

I don't have a hybrid nor do I use burst disks in my combustions very frequently, but I can assure you, one layer of heavy duty grocery-store type aluminum foil bursts at MUCH less than 90psi. I'd wager closer to 20.

Peace,
Pete Zara.

Cut out the plastic from milk bottles.That would go around...well im not sure you should find out.

shizm...well i was hoping for more then that...what about layering it up...like 3 layers, that would give you 60 or so

Just use milk bottles,more reliable,how big is your union going ot be? You should get loads of burst disks from a milk bottle.

aboot (hehe) 1"...i think...with a 2 inch chamber. and its gonna be a triggered burst disk gun. the only problem i have is that i use the organic paper milk jugs...not the gallon plastic ones. aybe i can use soda can metal...i have like a billion v8s that i never drink.

im gonna make a qev cannon in a month or so...but for now i want to make something and then maybe ill sell it to my friens.

Im using a 1 1/4" union and with one sheet of the cheep grocery store foil it bursts at +-5psi. But then when I layer it like 3 (if I remember correctly) burst at around 25.

Ill have to try out that milk carton idea! I didnt think of that.

Spose that will work, you might have a high bursting pressure unless like you said its triggered.

Plastic soda bottle burst disks hold the most pressure, unless you just want to use thin sheet metal.

Tracing paper works well, it holds more that foil (no idea on the exact burst pressure)

also i only have a bike pump (one day...one day) so i cant exactly just pump it up to 125 psi or untill it bursts..i need something that bursts at aprox 90-100 psi. i think ill do some test this weekend. i might post em for the greater good of everybody.

and speaking of burst disks, sgort gets the tip of my hat!

you could have a burst pressure of over 100 psi, because, as you said, it will be a triggered burst disc gun. just get a thicker material that will still burst when it is punctured. you could use pop can metal like gort did. good luck with this gun.

good point..i had thought of that at 11:30 last night while studying for my english test...but i forgot it when i fell asleep. im aming for pressures around 100, so the secondary chamber would be pressureide to ~50. so the 1st one would have to hold 50-60 psi and the second one just ~60.

also, how hard to you have ti puncture a burst disk to get it to fire (like sgorts design) he had a broad head moving pretty fast. cut he was using relatively thiick material. could you just design some sort of solenoid that oul hit it with a needle and would that fire it?

A solenoid is a small electromagnetically activated valve. What were you thinking?

You could just stick a nail in the back of whatever you're shooting and drop it in the barrel, mortar style.