Milk Bottle chamber

Boom! The classic potato gun harnesses the combustion of flammable vapor. Show us your combustion spud gun and discuss fuels, ratios, safety, ignition systems, tools, and more.
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qwerty
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Sun May 24, 2009 2:01 am

Do you think that one of those 6 pint milk bottles could hold the pressure for a simple deo combustion?
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Moonbogg
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Sun May 24, 2009 2:37 am

Glass? I need a pic. I'd suggest a 2 liter soda bottle before using that.
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qwerty
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Sun May 24, 2009 3:00 am

in the UK we get these big plastic 6 pint bottle thingy but i will try the 2 litre bottle first
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jackssmirkingrevenge
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Sun May 24, 2009 4:41 am

One of these?

Image

Yeah, why not. Should be just as suitable as this, and in the unlikely event of the chamber breaking, it will rip rather than shatter so you'll be quite safe.
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qwerty
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Sun May 24, 2009 5:24 am

Yea, thats the one that i ment
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inonickname
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Sun May 24, 2009 7:28 am

It'll be fine for the average pressure spray 'n pray generates.

If you wanted to reinforce it reinforce the flat sides, as they hold pressure much worse than the curved faces.
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far_cry
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Sun May 24, 2009 7:58 am

i this kind of bottles safe for combustion aneway

and
jackssmirkingrevenge wrote:Image
lol drink milk and shaving will be cheap
ImageImage
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Biopyro
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Sun May 24, 2009 1:11 pm

NO! I actually tested this the other day. even with a hole and a lighter for ignition they burst 9/10 times. You should ALL know better. Anything non round is almost certain to be a disaster for pressure containment.


Here is the instructable I wrote on it.
http://www.instructables.com/id/Make-a- ... explosion/

I also tested the bottles like jsr suggested, and found them to be rubbish too. When there was any friction in the barrel (a plastic bag), the plastic split along the seams. I am suprised that bottle held up to be honest.

It is, of course, HDPE so it's failure characteristics are very good, but had I been holding the handle it probably would have cut and burnt me a little (it split in the hand hold bit towards the handle.
Last edited by Biopyro on Sun May 24, 2009 1:30 pm, edited 1 time in total.
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Sun May 24, 2009 1:30 pm

Hmmm, it seems I stand corrected. Perhaps though with a significant outlet that would be a large calibre barrel (albeit with the weight of the projectile) this wouldn't occur.
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Biopyro
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Sun May 24, 2009 1:33 pm

I have to admit, I discovered it by accident. I was expecting that by using the lighter method, I'd get a nice rocket like effect, which did happen once, but usually it split. Even with a very rich or lean mix, it didn't fail to burst, it was just quieter.
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inonickname
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Sun May 24, 2009 10:54 pm

inonickname wrote:It'll be fine for the average pressure spray 'n pray generates.

If you wanted to reinforce it reinforce the flat sides, as they hold pressure much worse than the curved faces.
Biopyro wrote: Anything non round is almost certain to be a disaster for pressure containment.
I dunno. Some are pretty tough, while others are weak. Some I can jump on and the cap wont even pop off, and I aint small. Though come on, how hard is it to drink some coke? Then you have a much safer chamber. Or even just buy PVC.
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Biopyro
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Mon May 25, 2009 3:39 am

It's the corners which are weak, not the sides.

When pressure is applied, the two faces are pulling away fom each other where they meet, and so the corner has a lot of stress on it. I've found that the milk bottles in question tend to split on the bottom side corner.

A good few wraps of duct tape might help it hold, but as ino said, why not just get something tried and tested.

http://www.trssupplies.co.uk/index.php?cPath=134
and
http://www.hendersons.co.uk/Pipework2/index.html

are both very good value for online purchases, and Grahams have a good range of stock too.
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inonickname
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Mon May 25, 2009 3:49 am

Biopyro wrote:It's the corners which are weak, not the sides.

When pressure is applied, the two faces are pulling away fom each other where they meet, and so the corner has a lot of stress on it. I've found that the milk bottles in question tend to split on the bottom side corner.

A good few wraps of duct tape might help it hold, but as ino said, why not just get something tried and tested.

http://www.trssupplies.co.uk/index.php?cPath=134
and
http://www.hendersons.co.uk/Pipework2/index.html

are both very good value for online purchases, and Grahams have a good range of stock too.
Maybe, but the point still stands. Flat faces are much weaker than curved ones.

Btw; if you're using KMNo4 + S + Al don't use a milk bottle..Even though that would be naughty and against the rules..
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