Smoke-making compound
Duke said:
I want to test my bathroom and kitchen exhaust fan systems. I need a simple way to generate some white smoke in order to see if the exhausts are working properly. Any suggestion welcome.
When I was an aspiring scientist, I learned the formula for a smoke-making compound.
By weight:
75% potassium nitrate
15% powdered charcoal
10% sulfur
I could buy the sulfur and potassium nitrate at the drug store. I made the charcoal by heating some dry wood in a closed can with a little hole in the top until it burned off all of the volatiles; then powdered it.
It works best if you mix it all up moist and then dry it in the sun. That gets the constitutents to mingle well and the charcoal and sulfur stick to the grains of potassium nitrate, which is also known as saltpeter.
You can then VERY CAREFULLY use a wooden rolling pin on a wooden board or aluminum sheet to crush SMALL AMOUNTS AT A TIME into a powder.
Then put a small pile of it, spread out well (try a little at a time in a safe place) and light it with a long match. It will make a lot of smoke.
Be aware that what you are making is the same stuff that was used by the Minutemen at Lexington and Concord to fire "The shot heard 'round the world" on April 19, 1775. It was known as "Black powder".
I made a good bit of it on the farm in the early 1950s. You could do all kinds of exciting things with it out in the country. Luckily, I still have all of my fingers and can still see out of both eyes.
It would probably get the attention of ATF guys if you let it be known today that you were making it.