How to dry black match in the winter time

[SignalKanboom]

Can black match be dried in a room in a basement away from any source of ignition? Can it be dried outside in the winter assuming it is not snowing, or will the kno3 crystallize on outside of the match?

[Arthur]

That depends on what you call winter! Cold and damp days are no good and help is needed, but freezing clear and sunny days can dry well.

 

However given a winter day I'd probably chose to use a dehumidifier indoors. A local pyro used to have a dehumidifier and a rack really close than used to put a cardboard box over the two -things dried in an hour! It was a freezer sized box so he did big enough batches.

[SignalKanboom]

I would obviously avoid conditions involving moisture. Im speaking of freezing temperatures.

[MadMat]

Cold doesn't necessarily mean humid, in fact, cold weather can be extremely dry (think chapped lips). Unless you have a very dry basement, with a dehumidifier. a basement is the last place to try to dry something. Check your local weather conditions. If the relative humidity is low and it is sunny outside, go ahead and dry your black match outside. I have done it many times.

[justvisiting]

Keep in mind that in a cold, high relative humidity environment, there's FAR less moisture in the air than if the air was warm.

[Arthur]

The noon sun in a below freezing place is usually reasonably warm and very dry. An hour later may be cold again though.

[Sulphurstan]

Actually a good thing is to find an old, second hand refrigerator (which is usually air tight), put a bucket full of CaCl2, and hang the strings inside. Works fine for me (also used to store finished shells etc which must be protected from humidity).

Note: the fridge is of course not plugged into power! It is the air tightness which is important here

Edited December 15, 2020 by Sulphurstan

[SignalKanboom]

Doesnt kn03 precipitate at low temperatures? This is what Im speaking of.

[MadMat]

Doesnt kn03 precipitate at low temperatures? This is what Im speaking of.

When you make black match, you only add enough water to make a slurry. This limits the amount of KNO3 that actually dissolves. Additionally, you should add around 10% alcohol to the water. This further reduces the solubility of the KNO3 in the liquid mixture. You aren't actually dissolving much of the KNO3 to begin with. So it isn't a problem at all. To further inform you: The biggest problem with dissolving and subsequent precipitation of KNO3 in BP is the formation of large crystals of KNO3. If large crystals form, it basically ruins all the effort put into the ball milling of your BP. The actual size of a formed crystal is determined by the length of time it takes to form. The quicker it forms, the smaller it is. That is why in the "precipitation method" of making BP, cold alcohol is added (remember when I said that adding alcohol to water lowers the solubility of KNO3?). This cold alcohol causes the KNO3 to precipitate out of solution rapidly forming extremely small crystals that mix well with the Charcoal and sulfur at a very intimate level. So go ahead and dry your black match in cold temperatures, it won't matter. Besides, even if it does have any effect, you don't need super fast BP for black match!

Edited December 18, 2020 by MadMat

[Mumbles]

This is somewhat related. When potassium nitrate dissolves, it's endothermic. It's common to make slurry for blackmatch or add water for polverone using fairly warm water. As it mixes in, it cools quite a bit. I find it rather uncomfortable to use room temperature water as the slurry gets decently cold. The next step is often to kneed the polverone or kneed the string into the match, and it;s just a lot more comfortable and pleasant to use hot water to give a warm slurry or paste when you're hands are going to be buried in it.

[MadMat]

I hope I didn't ramble on too much. I know I sometimes do that when I try to explain something

[SignalKanboom]

Thanks to all! I didnt know the purpose of the alcohol. I will be sure to remember this advice.