2006-12-01 : Pyrotechnics

Play-related but not game-related: last night I made a film can cannon. (I couldn't wait for the weekend, J!)

It's fun and hilarious. I'm using a translucent white film can, so when you set it off you can see the blue flash of the (in my case) fingernail polish remover lighting up. It makes as satisfying a bang-pop noise as you could ask for. Firing it feels like you're getting away with doing something stupid, even though you aren't. Best!

1. On 2006-12-01, Vincent said:

Lunch hour experimentation:

Binaca is not explosive enough. It breaks the seal on my cannon, with a foomf, but doesn't pop the can clear off.

91% isopropyl alcohol is less reliable than the acetone nail polish remover. It doesn't go off on the first click every time, and sometimes it's a foomf and sometimes its a real launch. I don't know why. More experimentation is clearly called for.


2. On 2006-12-01, Andrew Cooper said:

Clearly.  This is all for the good of science.  The fact that it is fun to send small plastic tubes flying across the room by causing a mini-explosion has nothing at all to do with it.  This is all completely intellectual.


3. On 2006-12-01, Vincent said:

100% dry, passionless intellectual curiosity.

So it seems that the nail polish remover is a zillion times better than the isopropyl alcohol. It also turns out that I'm using non-acetone nail polish remover, listing ethyl acetate and alcohol as its first two ingredients.

Does anyone here know anything about chemistry? What's the difference between acetone and ethyl acetate? Does "ethyl acetate" sound like an alcohol on purpose or by accident?


4. On 2006-12-01, Julia said:

Acetone is a simple ketone and not an alcohol or an ester. Ethyl acetate is an ester, derived from ethanol and acetic acid. Ethyl acetate is non-toxic and is also used in the decaffeination process of coffee, and it is an alcohol. It is toxic to insects and is used in killing jars, when you want to pin a bug and display it. Should I go on? Do I sound like I know what I'm talking about? I have a rudimentary understanding of what I just told you, and can tell you some really bad things that ketones can do to you if you have too many in your blood (ketoacidosis). Chemically speaking, I can blah blah a few other little tidbits of information, and then lend you one of my chemistry books from nursing school.
If you can find acetone nail polish remover, I'll bet you'll get even more fun results.


5. On 2006-12-01, NinJ said:

The alcohol might not be working because of insufficient carburation. Experimenting with the mix will yield different results.

However, it seems like the acetone is more reactive. Using hydrogen peroxide as an oxidant might help. I don't know! H2O2 is 98% water, which might interfere heavily.

I kinda want to make a pistol-sized spud gun with this newfangled technology of yours.

Also, I have some cans of butane.

That could be the worst combination of ideas ever.

Also, the butane's stored right near the furnace.


Wanna make a butane-powered pellet gun? I do. Film canister charges, maybe?

You see what happens when you get excited and build something without me? It makes me escalate!


6. On 2006-12-02, Devin said:

Hydrogen peroxide will make a fine oxidant if you can get your hands on something concentrated.  The stuff from the drugstore, though, will not do.  As pointed out above, it's too dilute.

My guess is, when you get that "foomf," there's not enough oxygen available in the can, so you get a little combustion, enough to pop the can, and then as air rushes in the rest goes up, causing the foomf.  Hard to say without hearing it go, though.


7. On 2006-12-02, NinJ said:

Yeah, I think you're right, Devin. My understanding is that H2O2 in concentrations great enough to work as a propellant oxidant is extremely dangerous ??? like, burns through things like workbenches and people, and causes spontaneous combustion.

This of course means that I've always wished I could get some.


8. On 2006-12-05, Kaare Berg said:

You know that you can probably use this igniter in a quaterfull tank of petrol and really do something stupid.


9. On 2006-12-06, NinJ said:

As long as it's evaporated, yeah. Gas doesn't really explode until it's well aerated.

That's why there are carburators and fuel injectors.


10. On 2006-12-06, Julia said:

Here's a nice list of good potato gun fuels. Surely film canister cannons can run on the same?
Air freshener and deodorant—imagine that!


11. On 2006-12-06, Vincent said:



12. On 2006-12-06, pete_darby said:

Go to the government and demand your jetpac and flying car NOW!


13. On 2006-12-06, NinJ said:

Yeah, the butane is very interesting to me. I think I've got a way to get the right amount. I'm also thinking about it as a fuel for a small pulsejet/


14. On 2006-12-07, Valamir said:

there is no better, or more readily available, propellant than Aqua Net hair spray...

That stuff in potato gun made of PVC pipe with an electric grill igniter can blow a 2 inch limb off a tree AND make mash potatoes at the same time.

It also makes for a great flame thrower...if you're brave (i.e. stupid) enough to trust the seal on the aerosol dispenser.


15. On 2006-12-19, cenoxo said:


A few questions about your use of non-acetone nail polish remover in the film can cannon:

1. Brand of remover?
2. Store purchased from?
2. How much do you use?
3. How do you put it into the film can?

I've built a couple of film can cannons. They work fine with Binaca Aerosol Breath Spray, but I'd like to find an alternate fuel source.



16. On 2006-12-19, Vincent said:


1. Top Care non-acetone nail polish remover (protein enriched).
2. CVS, I'm pretty sure. Maybe Brooks Pharmacy.
3. 4-7 drops.
4. With an eyedropper I bought at the same time, for the very purpose. I drop it in - drop drop drop! - and then swish it around some. There's so little of it that it barely pools at the bottom of the cannister.

It's kind of stinky. I wish the Binaca worked for me. Maybe I'll do some more experimentation. I'm working on a big film can cannon-related project for my kids, and I think Binaca would be the better fuel to turn them loose with. I wouldn't worry about them spilling it all over, for instance.


17. On 2006-12-29, cenoxo said:


Appreciate for the answers: I'll give the acetone-free NPR a try. I wonder if acetone-based NPR might eventually attack the film can plastic?

Binaca Aerosol Breath Spray definitely sounds better for supervised kid use. One squirt (from about 3"-4" away from the film can) has worked great for me: I usually warm up the Binaca can in my hand before spraying it.

I've had very few ignition problems, mostly from spraying in too much Binaca. Pop off one edge of the film can for a few seconds to let a little air in, snap it back on, shake the cannon, and click the igniter again.

I've also tried AquaNet Hair Spray, but it's tricky to repeat small doses, and sometimes flaming residue remains in the flying film can. Pretty alarming when the can lands on carpet or a couch...

RE misfires, some film can lids have tiny plastic teeth in the groove around the lid's inside rim. These hold the film can's top edge too tightly so it won't pop off easily. Be sure to use gray or black lids that have a smooth inside groove without teeth.


18. On 2006-12-29, Vincent said:

I wonder if my problem is that I'm using Binaca non-aresol breath spray. I'll investigate further.

I've also gotta get some photos up here. I made pirate ships!


19. On 2006-12-29, NinJ said:

No, it's atomizing well. I think the key is to spray from a few inches off so it gets fresh air in the mixture.


20. On 2007-02-11, JUGGERNAUT said:

OK, So ya want to make a butane powered pellit pistol. I have ponderd on the ideal myself for quite sometime, im probly going to use PVC pipe with threads on each end for caps for the combustion chamber and find a small metal pipe suitable for a pellit, and the bottom of a refilable lighter to be able to fill the the chamber with gas easy , and of course a peizo ignighter with some umph, oh and by the way Valamir the binaca and hair spray and all that other jazz is no good for nuthing but potato guns and ruins them, because it makes all the working parts get sticky and unuseable in time, so stick with butane,this would be cheap and easy to make a high powerd pellit gun.


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