Change of plans. Instead of the CIA method I've begun to invest in the ball mill corning method. This will provide more potent powder that will pretty much equal the commercial stuff, but will cost a big bunch more to gear up for making it.
Basically, the three main ingredients - KNO3, willow charcoal, sulfur - are ball milled for many hours, 8 to 12. Prior to ball milling, the KNO3 is refined to AF (air float) quality using an electric bean grinder with ceramic burrs. The sulfur and willow charcoal are already of AF quality.
After the milling, the results are "meal powder" that go into a bowl that gets water and/or 70% IPA (isopropyl alcohol) sparingly dribbled in and mixed up with rubber gloved hands to the point where the mix will "clump", meaning it's between moist and damp, NOT wet.
A few scaled (for weight) tablespoons of the mix are put into a pucking die. The one I have is from Woody's and will make 3" BP pucks that are about 3/16" to 1/4" in thickness.
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The filled pucking die sits on a Woody's pressure gauge that goes to 6000psi.
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Between the weight of the meal powder and the amount of pressure used to "corn" out the pucks, that's all for some measure of consistency of the resulting powder.
The pressure gauge and pucking die go into a 20 ton press that will press down the powder, fusing it together at around 3500psi. The sulfur will "plasticize" and fuse the three ingredients together, and that's the essential key to making really GOOD black powder, as done commercially.
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The resulting BP pucks are hard and initially shiny (due to residual water content) and are allowed to fully dry to a dull look in a day or so.
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Then the pucks are broken up and go into a hand grinder that will grind down to granules that are between 1F and 4F in size.
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The resulting powder is sifted through 2 or 3 screens for size. Any sizes too large or too small are kept for making more pucks.
NOW, how dangerous is all this??Well, from my perspective, after spending weeks reviewing all the processes for making Good BP, not as much as one would think. Mixing the three key ingredients dry is of some concern, but if a proper ball mill is used - internally rubber lined, and lead balls are used for the grinders - there is pretty much no chance of an explosion happening. It takes a heckuva LOT of heat to touch off black powder. I'll be milling outside and far away from anything important to get blown up. Once the milling is over, the meal powder is handled just as we now handle black powder for our firesticks - carefully.
The corning process starts with wetting down the powder (so no chance of ignition), compressing the damp powder, and then allowing the resulting pucks to dry out.
The next big concern is breaking up the pucks (literally with a hammer over the cloth covered pucks) and then taking one puck at a time to the hand grinder. Again, the bugaboo for igniting black powder is heat, not static electricity. Can the grinder created a spark of heat to kick off the powder in the grinder's hopper? I don't see how that could happen as there is nothing in or about a grain grinder that would be capable of creating the kind of spark that a flint on a frizzen will create, nor has any such incident been recorded.
Are we havin' fun .... yet?