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Hey makers! We’re looking for true stories about dangerous maker experiences for an upcoming issue of MAKE. Do you have one to share?

I’ll get the ball rolling by sharing one of my own:

Why You Shouldn’t Make Smoke Bombs in Your Friend’s Kitchen

When I was 12 years old I got my hands on a copy of Abbie Hoffman’s Steal This Book, a guidebook for pranks, protests, and overthrowing the system. My favorite part of the book was the “People’s Chemistry” chapter, which had recipes for making stink bombs, smoke bombs, Molotov cocktails, sterno bombs, aerosol bombs, pipe bombs, et cetera.

Here’s Hoffman’s recipe for Smoke Bombs:

NewImage.pngSMOKE BOMB

Sometimes it becomes strategically correct to confuse the opposition and provide a smoke screen to aid an escape. A real home-made smoke bomb can be made by combining four parts sugar to six parts saltpeter (available at all chemical supply stores). This mixture must then be heated over a very low flame. It will blend into a plastic substance. When this starts to gel, remove from the heat and allow the plastic to cool. Embed a few wooden match heads into the mass while it’s still pliable and attach a fuse.

The smoke bomb itself is non-explosive and non-flame-producing, so no
extreme safety requirements are needed. About a pound of the plastic will
produce thick enough smoke to fill a city block. Just make sure you know which way the wind is blowing, Weathermen-women!

After a bit of research I learned that the chemical name for saltpeter is potassium nitrate. I called the pharmacy department at the local Kmart and they told me they had it in stock. I rode my bike over and bought a pound. When I got home I set up my Boy Scout camping stove in the backyard and melted a batch of potassium nitrate and sugar in a frying pan. After letting it cool and forming it into a lump, I placed it on the asphalt of the cul-de-sac I lived in and lit it with the match. An astonishing amount of opaque white smoke gushed out of the bomb. The smoke bomb itself liquefied and bubbled like molten lava for quite a while afterward, causing damage to the asphalt.

I invited my friends over and we made more. The next day we bought every container of potassium nitrate that Kmart had in stock. The guy at the pharmacy counter gave us a funny look, but didn’t ask us why we were buying it.

With all that potassium nitrate we wanted to make a big batch so we’d have plenty of smoke bombs on hand for Fourth of July. The small camp stove I was using would not be sufficient for our ambitious plans. I asked my friend if we could cook it up in his kitchen. He thought it was a great idea. We went to his house, dumped a huge amount of potassium nitrate and sugar into a 8-quart pot and cranked up the burner on the range. His mother asked us what we were doing, and we explained that we were making smoke bombs. She asked if it was safe, and I told her that we had made it a bunch of times before, and no one had been hurt (which was true). Potassium nitrate is white, like sugar, and it looks innocuous, so she just told us to be careful and left the kitchen.

My friend and I took turns stirring the mixture with a wooden spoon, waiting for it to start to get soft and melt. But nothing was happening. We turned up the burner. Ten minutes later, still nothing. Suddenly, my friend remembered that he had the new 10 Years After record and asked if I wanted to listen to it in his room. “Sure,” I said. “We can check on the smoke bombs in about 10 minutes.”

We were in my friend’s upstairs room for less than two minutes when we heard a strange rumbling sound, kind of like a vacuum cleaner but lower pitched and more throaty. We looked at each other with fear and ran out of his room and down the stairs. We heard my friend’s father scream “Holy shit!” By the time we got to the bottom of the stairs the entire first floor was filled with opaque white smoke. I felt like I was lost inside a giant bucket of milk. In the kitchen, we could see puddles of molten smokebomb mixture on the floor, counters, even dripping off the ceiling. The puddles were glowing red, barely visible through the smoke. My friend’s dad had run to the backyard to get the garden hose and was spraying water into the pot and into the burning puddles of smoke bomb lava.

Fortunately, no one was hurt. The property damage wasn’t too bad, either, but I got grounded nonetheless. I was especially thankful that my parents didn’t forbid me from making smoke bombs. The only stipulation was that I had to go back to making it in our backyard with a camping stove.

Okay, that’s my story. What’s yours?

Mark Frauenfelder

Mark Frauenfelder is the editor-in-chief of Make magazine, and the founder of the popular Boing Boing blog.


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