Archive for September 28, 2013

Smoke Bombs?

Jacob came running inside yelling for me. “MeeMaw, MeeMaw! We’ve been burning the smoke bombs. Come see them!”

I’d picked up a pot from the dollar store in which their smoke bomb ‘cooking’ was to take place, along with 5 pounds of sugar, so I knew they were making them this morning. I didn’t know that they’d been igniting them without adult supervision, though.

I went outside and SwampMan was looking at the deeply charred and still glowing boards of a wooden bench. The aluminum foil he’d put over it to ‘protect’ it was mostly melted/consumed.

“So, smoke bombs, hunh? What is the melting temperature of aluminum again?” I asked.

“About 1,200 F”, he remarked absentmindedly. “Something must have gone wrong. This is more like thermite.”

“Hmmmmmmm.” Somehow I’m not too surprised when his backyard chemistry goes awry.

“MeeMaw, MeeMaw, LOOK!” Dylan called to me. I ‘accidentally’ lit the smoke bomb on fire upside down, and it exploded the concrete. See my arm?” He showed me a combination scratch/burn. SwampMan got the hairy eyeball. BIG time.

“What? I lit the first one!”

“You mean when you set the bench on fire?”

“Well, yeah.”

“So, what are the other ingredients in that stump buster besides potassium nitrate?”

“I dunno.”

“Hmmmmmmm. Might want to check if it has any magnesium or aluminum.”

I gave them a flowerpot half filled with dirt in order to light the next one. Jacob lit it. The heat was intense. The smoke was moderately impressive. Then they put another one in, and it looked like a volcanic flower pot. The ceramic flowerpot cracked all to hell from the heat and, no, it had no water in it. It had been inside a sheltered shed for several years.

Next week’s project is solid rocket fuel, I believe.

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