1L Coke Bottle with 7mm( ~ 0,3") barrel?

[VirusX]

Hi,

I got nothing to do so I wanna build a little combustion cannon with a 1L Coke Bottle.

I wonder wether the Coke Bottle would explode when I use a 7mm (or ~ 0,3", I think) brass pipe as barrel for steel softair ammo. I mean, the air pressure would be very high in the bottle because of the little barrel!? (I think I'll use deodorant, lighter gas is too dangerous)

-And I've got another question:

I'll use the breech to spray the deodorant in the bottle, so the barrel must be on the ohter side of the bottle. Any idea, how to glue it strong together? The boards of the bottle are very thin, the barrel wouldn't be attached right?

[Mr.Sandman]

when you say lighter gas? do you mean butane? because butane is just as powerful as deoderant and wont gunk up your chamber. And no your gun wont explode the pressure wont be that high. Its nice to see your taking precautions but its no hybrid thats for sure. you will be fine.

[inonickname]

Just use epoxy and secure the barrel through a hole in the cap. The max pressure spike of a spray n' pray is around 30 psi, nowhere near enough to burst a coke bottle.

[VirusX]

Ok then I start to build this little one now, thanks for your help!

[jaythedogg]

I made one similar but with a 2 liter bottle. I took a 2 liter, epoxied a 1.5" ID schd. 40 PVC pipe (4 foot) as a barrel & melted a hole in the very bottom of the coke bottle using a grill lighter in one of the "feet" of the 2 liter.

I melted the hole by heating it with the lighter & forcing the grill lighter through it.

Took a propane torch, sprayed some propane in it (a 1 second blast) & stuck the lighter in (after loading a wadding & a pill bottle filled with sand).

BOOM! Fired fine, about 50 shots before I retired it.

The thicker walled 1 liter bottle should be fine.

However I used a bug juice bottle & hot glued a small barrel for mini marshmallows in it, then a short length of the same cardboard barrel material for a fuel port/lighter hole.

That one worked great for shooting marshmallows with propane, but after a 5 second spray of propane & like 10 marshmallows in the barrel I heard a boom & held the lighter with the rear end of the bottle with one hand, the rest in the other.

Ears ringing & wow, yea, they cannot take large blasts of propane with an over plugged barrel.

In retrospect I think it was the cardboard barrel. I believe it got moist from the propane shots & the marshmallows stuck during the last shot.

Long story short, you should be fine, even if it does pop, odds are it will just scare you with the bursting bottle deal.

Wanna be safer? Wrap the 1 liter bottle from the rear most point of the side to the barrel with a few (not stretched at all) layers of electrical tape. Therefore it it does pop, it should only blow the end off, as it will go for the weakest point.

Been my experience anyway.

Just use epoxy and secure the barrel through a hole in the cap. The max pressure spike of a spray n' pray is around 30 psi, nowhere near enough to burst a coke bottle.

Wait, so you think a 5 gallon water jug (One of those like Culligan uses) with a 1.5" PVC barrel would handle propane shots okay?

[jackssmirkingrevenge]

PET bottles made for carbonated drinks are normally rated for 200-300 psi, no problems with using them in a combustion. Containers made for still water tend to be weaker though (it makes economic sense to have thinner walls if the strength isn't needed) so caution should be exercised.

(I think I'll use deodorant, lighter gas is too dangerous)

No more dangerous than igniting deodorant. Here's another way of getting the same/similar gas:

[VirusX]

PET bottles made for carbonated drinks are normally rated for 200-300 psi, no problems with using them in a combustion. Containers made for still water tend to be weaker though (it makes economic sense to have thinner walls if the strength isn't needed) so caution should be exercised.

(I think I'll use deodorant, lighter gas is too dangerous)

No more dangerous than igniting deodorant. Here's another way of getting the same/similar gas:

Why is deodorant dangerous? Aren't there much more dangerous gases like butane or propane!?

The only problem with deodorant is, that everythings gets slushy ... I have more and more problems to ignite.

[jackssmirkingrevenge]

My point was, it's useless being worried about butane and propane then not worrying about deodorant, one isn't really more dangerous than the other.

[VirusX]

Hi,

I tried to glue the barrel and the bottle together with epoxy. So I mixed the 2 glues together, put some of it on the barrel, moved both pieces together and clamed it in the screw clamp.

The glue starts to drip and clears off.

What can I do against that dripping? In the manual stands, the glue needs 2 hours to get fix and some more hours do get really fix.

(Sorry my English is bad )

[jaythedogg]

First, put a dot of hot glue around the connecting points, about a quarter of the way around for each spacing. Then stand it on the bottle neck & prop it up, then use some 1 minute fast epoxy. It isn't as strong as 2 hour epoxy (the faster the epoxy set time, the more of a crystalline bond, which equals less tensile strength) but it is plenty strong enough for this application. Do a small amount in relatively thin layers, doing multiple layers quickly, meaning every 30 seconds so it doesn't completely dry between coats, allowing the individual layers to bond better.