Cannons, fireworks, experiments, projects

[vutch]

My grandfather tells stories about how they used to use dynamite as an all-purpose tool on the farm when he was younger. His uncle especially was the "dynamite man" around. They moved lots of stumps and rocks that way. Once in a while there would be a woodchuck or some other wildlife under the stumps when they blew. Needless to say, they came out in lots of small pieces. They still have problems around us with kids (or adults) finding dynamite that got shoved in the corner of an old shed years ago.

Also, I worked for a summer at a local company that makes fire extinguishers (Ansul is the name, you've probably seen it on many extinguishers). Anyway, the higher quality models store the dry chemical and the propellant gas (CO2 or nitrogen) seperately. The chemical is in the main tank, and the gas is stored in a small cylinder about 6-8 inches long under extremely high pressure (see photo). The top of the cylinder has a cap with a foil-type insert (how it holds that much pressure in, I dunno). When the extinguisher is used, a needle punctures this insert, allowing the gas to pressurize the dry chem tank. Well, I heard stories about some of the guys who got bored on the night shift and made a launcher with a piece of pipe with a nail in the bottom. They'd go out back by the river on breaks and drop the cartriges in the pipe so the nail punctured the cap. I guess they found some of those cartriges a ways away across the river!

Chris

 

[patrickg]

Doc_Heb, You don't have to use anhydrous as regular houshold ammonia works good enough for the "home" experimenter. Great stuff to scatter in the hall to be stepped on when it dries. So unstable that we always separated our batch into sub batches on separate pieces of filter paper to dry as it sometimes went off for no discernable reason toward the end of its drying time. Pretty harmless,yo can set off a small portion by touching it with your finger and suffering no damage except an iodine stain blast mark. It was fun to put it on door jams, pencil erasers, etc.

Is crystalline iodine still readily available to the average Joe?

I used to like to "fuel" a plaster of paris miniature volcano with potassium permanganate and glycerine (not nitro, the hand lotion rose water and glycerine kind). You make a pile of the potassium permanganate and form a depression in the top like in mashed potatoes to hold the gravy. Put a heaping table spoon or two of the glycerine in the depression and stand back and wait. The strong oxidizer (potassium permanganate) starts to work on the alcohol (glycerine is an alcohol) with a strongly exothermic reaction. The heat generated catalyzes the reaction, further speeding it up and creating more heat etc. until the glycerine bursts into flame with lots of purple sparks shooting up and smoke billowing out, makes a credible miniature volcano.

Both sodium is a soft butter like metal at room temp. It oxidizes easily and gets rather violent in contact with water so is usually kept under oil. Anyway, it can be placed in a floating container and set adrift. Sinking the container remotely with a pull of a string or whatever puts the metal in contact with water where the metal literally tears the water apart. Water can be expressed as HOH (2 hydrogens and one oxygen) the Na (sodium) rips the water apart to become Na OH. The rest of the water H is set free. The reaction is highly exothermic and causes the released hydrogen to ignite with oxygen in the air AND to heat the water in contact with the reagents past the boiling point which causes a steam explosion. So there is a small fireball from the burning hydrogen and a steam explosion which hurls outward the liquid in contact with the reaction. One the products of the reaction is Na OH, sodium hydroxide (AKA lye). So lets recap. You have a hydrogen and steam explosion that hurls lye water and unreacted bits of sodium. Each of the unreacted bits of sodium, when it lands on the surface of the water, does a repeat of the previous performance that shot it outward. So you get an expanding starburst effect, limited only by the original amount of metal (sodium).

DO NOT, I repeat, DO NOT try this in the sink. I suppose K (potassium) which is similar would do about the same thing but I can't confirm that from personal experience. As I was a lab assistant to some teachers in high school where way too many large quantities of dangerous things were kept, I was in a position to destroy some things best not kept where they might fall into misuse.

Pretty spectacular to see, from a distance, especially with a stick of the stuff nearly the size of a stick of butter.

Patrick

 

[MikePA]

Henry, the link you posted (http://www.aaroncake.net/spuds/ ) doesn't exist. In fact, the domain, aaroncake.net, doesn't exist. Might want to double check it then edit your post to correct the link.