See. This is what you get when you do it wrong.

[paul skinner]

Now. Why does this remind me of some of the topics of discussion on mixing agent "A" with reactant "B" on pulse-jets.com....and wondering what the outcome will be.


(this is not meant as a lecture. More of a "just because you can. Doesn't mean you should....warning, visually shocking. No bones, guts, or blood, but still enough to make you jump).

The video (credited) comes via orsm.net

http://grab.orsm.net//update20051117/byebyehand.wmv

[Tom]

This is what annoys me actually, one of my pet peeves. A few of the guys I know like to play with fire, yet they never know the chemistry behind what's going on, so they often injure themselves from a reaction that got out of hand.

If people just had a little bit of chemical knowledge, so much like this could be avoided.

[Dang911]

That reaction was quite deadly on more than one aspect. They mixed powdered chlorine, with ammonia. Making copious amounts of Chlorine gas. Not only did all that gas explodes in there face (one sniff will kill), but the acid had to of burned them. Not to mention the shrapnel from the bottle explosion. This is a definite, DON'T TRY THIS AT HOME!!!!!

[Mike Everman]

god, that sucks! Give me hydrocarbons and oxygen at less than 2 bar in an open container, please.

[Mark]

I remember reading one of those intellectual model airplane articles in a magazine where one of those tiny CO2 piston engines was being run with a pressurized 2 liter plastic bottle. When I say intellectual, I mean the writing style was clever and colorful, with a lot of insight. And while I can't remember it very well, I do remember reading it with interest as the writer described what it feels like to have one of those 2 liter PETE bottles explode verg near you when you accidentally over-pressurize it. He described some sort of vibrational wave going through his whole chest and abdomen. He wasn't hurt but he was "inspired."
Here's one I blew up shot at 1/1000 of a second, dry ice and water. You can see the ruptured bottle in the ~ left-center traveling to the left and upwards. They are really quite loud, like a small cannon. Your eyes don't see the vapor cloud or bottle, only your ears sense what happened.
Mark

[Dang911]

You know I have attempted several times to make one of those dry ice bombs, the last attempt was only 3 days ago........

I HAVE NEVER BEEN ABLE TO GET MINE TO EXPLODE. I end up having to shoot the bottle to safely discharge the pressure.

I have tried it with very HOT water, filled 3/4 to the top, and a put (what I though) a lot of dry ice in the bottle. Screwed the cap on and ran. Waited a good 8 min before I would give up and shoot the bottle.

One thing that has remained constant is the bottle I am using. I always use 2 L seltzer water bottles. Maybe they are more reinforced because they are meant to hold carbonated water, but I would think the same need for reinforcement would be necessary for a coke bottle, too.

What should I do differently.......

[Mark]

Looks like if you hold the bottle in your hand, it is more likely to explode. ha
I can't imagine what your problem is Dang, I use about a cup of dry ice and a cup of water and even less the smaller size bottle you go, it's been awhile for me but you could try using a different bottle, try a 2 liter or 3 liter Coke bottle. 3 liter bottles are easy to drop big chunks of ice into, having that wider lid. If you fill the bottle with a lot of water, you aren't leaving much room for the gases to expand and you will have shortened your window of safety. The same if you use too much dry ice, it pressurizes the bottle faster.
Listen to what the bottle is telling you, perhaps it is leaking or hissing from the cap design. Stand behind a tree and don't dawdle when screwing on the cap and tossing the bottle.
Never approach a failed bottle, it can surprise you just when you think it is safe.
Do be careful, think about what could go wrong, what it would be like to wear an eye patch, etc. Maybe wear googles.
Mark

[Dang911]

In the time it takes for a bottle to explode, the warm water will not cool down, I figured I was just using too little dry ice...... Hot water will always give you the best sublimination rate, and by filling the bottle 3/4, there is less room for gas to expand, so it should explode a lot sooner, I just need to use more than 3-4 pieces into the bottle neck, you guy said close to a cup!

[thecheat]

well, I thought some of you may want to know, the safe limit on 2 liter bottles is 150PSI, which means it can go over that but the bottles themselves are safely rated at the 150PSI.

heh I've made a few of these and putting water in them is not the best way to make it explode. the hot water will cool as soon as you put the dry ice in, and waste the gasses. The BEST way to do this is put 4-8 chunks the size of your thumb in, close the cap, and KEEP IN THE SUN! this also doesn't work very well when it's cold outside (under 50 F)

I will say these things are quite strong, we had let them sit for around 1 hour, and nothing had happened. So my brother went out and tried to stomp/jump on it, nothing happened still. We fortunatly made it out safely as we hadn't known how loud it would be. (we're in a suburban area) heh we had around 6 or seven of them out there. when we called the neighbors to tell them it's ok we got some funny replies... "I thought your (my) hovercraft had exploded!"
Using them at a larger acreage (280) we found we could hear it from around 1-2 miles away.

[Mark]

More scientific testing, including BB gun data. ha
Mark
http://home.earthlink.net/~lenyr/exp1.htm

[Mark]

I just noticed on the above link about BB's and bottles, that from that site there is a link to the mind-bending "Jet Negative Thust by Sucking" debate of Feynman for all the putt-putt boat fans out there. It's been posted before, but for those who haven't suffered ...
Eric's barstool negative thruster blunderbuss comes to mind, I wonder if you could use "that" principle to make a reverse thrusting putt-putt. Then too, I wonder if you could make a miniature Chinese and heat up a portion of it and have it run ala putt-putt underwater too?
Mark

[Mark]

The link again.
Mark
http://home.earthlink.net/~lenyr/jet.htm

[Jonny69]

Yeah we just used cold water in a 2l bottle filled about 1/4 to a 1/3, a handfull of dry ice, lid on and throooow! Sometimes they swell up to about twice their size before kaboomie. We blew a bin off a lamp post.

[larry cottrill]

The indoor version is to use white plastic cannisters for 35mm film and no water. One chunk of dr ice is reusable in them a number of times, and they'll launch 20' or so in the air, when you set them on a hard surface cap-down.

It would be a "blast" to use these horizontally as propulsion for tiny boats (perhaps in a contest format) at a school swimming pool. Imagine trying to design a tiny boat that would be stable for a short blast of propulsion. A race or contest could consist simply of whose boat goes farthest before coming to rest.

Of course, never having seen it, I am assuming that the cap blows off all at once, giving a straight-ahead propulsive blast. Is this the case, Ben, or do they just go off in unpredictable directions?

L Cottrill

[Mark]

I don't know if this would work or not, but reading this thread brought something to mind. You know those ordinary dishwashing liquid bottles with the snap on tops? Well, out of curiousity, I kept one of the lids, rinsed it off and screwed it onto a 2 liter Coke bottle as pictured in my attachment. One of the soap caps is screwed onto the Coke bottle and another two are shown, again just ordinary caps along with the red Coke cap so you can see they are the same size.
But a strange thing I discovered, and this is kind of strange, but it's me. I screwed one of these soap caps on the two liter bottle and blew into the cap as hard as I could and then snapped the little snap cap part shut as fast as possible. You wouldn't believe it, but the Coke bottle will hold the pressure for a few days. There is a plastic groove in the cap that the lip of the Coke bottle must fit into perfectly I guess. It has no soft gasket material like the Coke cap.
So I was thinking, maybe, if you clipped the snap cap part so it doesn't hinge with itself if you will, perhaps a chunk of dry ice, the Coke bottle, and the soap cap would make for a good self-firing toy. Again, I would cut the hinge part of the cap so that part could fly off free and clear when/if the pressure forces the plug pin in that part of the cap free. Perhaps you could alter it slightly if the bottle blew up. I just like the idea of the supreme simplicity. But again, caution! Don't stand right next this arrangement in any case, it very well may not work, (think explosion), or you could get a defective tighter fitting snap cap pin that might ruin your day.
Or maybe you could devise a little plug of rubber or something to fit in the tiny soap cap hole, make your own little release pin. The nice thing about the soap cap is that it has a little bit of nozzle to it. I originally was toying with the idea of using the Coke/Soap parts for a quick and simple small fuel tank using a smaller bottle. And also I have wanted to use this cap and bottle for another thing, but I will spare the forum until I actually do it. Getting to the experimentation phase is noble indeed.
Mark