SpudFiles

I've been experimenting a little since I got a bunch of schrader valves, pressurizing anything in sight, and I've found water bottles are fantastic noisemakers.

Mid pressurization. Small leaks mean that when you stop pumping vapour inside condenses, as soon as you start pumping it disappears in about 2 pumps. It's fascinating to watch.

A coke bottle after about 160psi. Even a small amount of heat (hairdryer) causes it to deform, and it has none of it's normal elasticity when you squeeze it. Repressurizing it brought back to this bulged state.

The best (loudest) bottle I tested. It's one of the smooth walled ones available in boots. This lack of imperfections meant it bulged around 120 and blew at ~140 It made my ears ring slightly through earplugs, and I felt the concussion!

The re-usable burst disk lucozade bottle*. I cut a hole in the lid and used plastic as a burst disk. Only tested it to around 100psi when the lid broke, but sounded good, a fair gunshot crack. I plan to test it with tougher burst disks and see how it compares to a whole bottle. Plastic and Al foil aren't really strong enough. Can anyone suggest anything similar that might work? The diameter of the opening is about 2cm and anything too thick means the lid can't screw on properly.

As for the safety of using fizzy drinks bottles as chambers, I reckon they're pretty safe up to 100, then ambiguous to 140, then dangerous. Even past 160 I couldn't get it to burst, despite the swelling. I removed it from the pump (probably dropped to about 150psi) and threw it to the ground - nothing. I then threw it with all the force I could and the lid blew. The bottle itself crumpled on what I assume to be where it hit the ground but I'm not totally sure. The lid had split completely and the schrader was nowhere to be seen.

Mr.C had a thread a while ago about dry ice and bottles. I've pressurized bottles to 120 psi then shot the bottom out with my pellet gun. The noise was quite loud.

They do make perfect targets..

Wouldn;t that make a very simple cannon now..

Precharged bottles, and a spike.

Test if that would completely rupture them...You could make it a breech loader.Open up the back, put in a tater, followed by a 110psi precharged bottle, close the back.
And fire a springloaded spike!

I believe selfcontained ammo is illegal, so that's why I suggested the two step load.
It does have potential...

Precharged bottles, and a spike.

My uncle did that with 12g Co2 cartages and a spike

What size pipe would 2 liter bottles fit in then, or would soda bottles work also ? You could then use a chamber insert bottle then boom !
Time to start downing mountain dew

dudeman508 wrote:

Precharged bottles, and a spike.

My uncle did that with 12g Co2 cartages and a spike

Jesus .




I suddenly really want to try that .

trigun wrote: Time to start downing mountain dew

Already started!

I did one test to see if the burst disk would rupture fully from being punctured and the answer was no, however, it was nowhere near it's burst pressure. I will try again today because I think that could be a pretty cool idea.

Also, I plan to try adding butane for a hybrid effect. a 7x mix like that should really give a good concussion, but I need a way to add the butane in a metered fashion. I was thinking syringe, because there isn't really a way I can add fuel when the bottle is pressurized, but there aren't any syringes that big!

Insert butane -> then start pumping.

Might need some kind of heavy duty cap replacement or get one cap and reinforce the heck out of it to have the ignition and fill valve safe from going sightseeing after the combustion.

Something along the lines of building up the outside of the cap with polymorph could work.

ok, you uys do know that we are tyring to get people to stop using bottles as chambers it doesnt matter if its just a 'noisemaker' it can still end badly ie loss of sight, and then you go and sugest hybrid mixes? sorry guys not in in my book.

sending COMPLETELY the wrong message.

I personally have never seen the problem with using soda bottles. So maybe they can't hold as much pressure as pvc or other types of chambers but I can't recall seeing one that failed explosively.

i have seen many that have failed explosively, one in person which left my mate with a permanent ring in his ear and a scratch near his eye

the problem is there is too many factors that relate to thier failure such as lower manufacturing tollerances.

SilentCyan I can tell you now, I've seen around 10 fail very explosively. I think the danger is not so much shrapnel as it is hearing damage because this things are LOUD!
Carlman - Not one of those however was one designed for pressure. Dr pepper and coke bottles both swell at 180 but do not explode even when given a good smack at 160. I would love to know the circumstances of your friend's accident, perhaps these can shed light on why - temperature, re-use etc?
Hotwired - thats exactly what I was thinking, except keep the normal lid and secure the wires and schrader with polymorph, then tie it with some secured fishing wire, so that I can find it if (when) it shoots into the distance.
My problem is more how to measure the propane. I don't want to pump it up all the way only to find the mix was incorrect. Perhaps this will never come to reality...

i guess mileage varies with the things

darn it, another idea stolen out from under me (even thought I never posted it). I was going to make a mold of Plaster of Paris, and pour a new cap out of zamak 27, and put on a sparkplug and a schrader.

I just bought an ignition coil off eBay, so you may see it posted. BTW, I have an EX-F1.