Ian
Notorious member
A new quest of mine. Finding myself with the illness that follows being bitten by the muzzle-loader bug, flint lock variety this time, that old partial pound of Goex 3Fg powder didn't last long and the Graf's house brand I bought just to have hangfires almost as badly as straight Pyrodex if it lights at all. I always wanted to fiddle with flinters and brewing my own fuel so here goes.
Three simple ingredients, put it together a certain way, and presto! Gunpowder! Well, not quite. Here's what I've done:
Got some technical grade, granulated KNO2 and sulfur, a dedicated kitchen blender, a small rock tumbler, a manual coffee grinder with ceramic wheels, and some brass ball bearings. Also picked up a stackable set of grading screens in 10/20/30/40/50 and 60 mesh.
Then I took one of those sheet metal popcorn tins we all have left over from Christmas and cooked down some small ricks of Red Alder in a couple of different batches (holding at different temperatures) and some seasoned Chinaberry in another. Turned the finished charcoal to airfloat in the blender and immediately put in sealed mason jars.
First go in the little rubber ball mill canister with brass balls, I did the 75/15/10 mix by weight and let it run. After checking a few times it took about 28 hours to get dust, definitely needed improvement. So I damped the dust with 91% isopropyl alcohol until it would just start to clean the sides of the container (like making pie crust) and riced it through the 20-mesh screen. After drying, I re-screened it into 3F and 4F and did some open-air burn tests (light a line of it off) and it seemed almost as fast as Goex but didn't put off quite as strong of a pressure wave or heat blast. Riced powder never has the oomph of corned so I wasn't surprised.
I enjoyed shooting this powder in several percussion guns and my flinter rifle where it worked great but of course was pretty low in velocity compared to Goex and Graf's of the same grades. My stuff lights in the pan VERY well.
After the first go I'm left with two problems to solve: Need mo' powah and stronger granules. The riced powder kernels easily crush to dust between thumb and forefinger, will not withstand polishing, and won't work in a powder horn very well. I also suspect the kernels will revert to dust quickly in storage. Corning is supposed to fix both problems, so I tried that. 1.5" ID heavy aluminum tube with a piston turned to match was used in conjunction with a 20-ton hydraulic shop press to produce corned pucks of very high density. I used alcohol to just barely dampen the meal until it stopped making dust when stirred with a spoon in a container (just a few drops, in other words) before corning. Then I broke up the dried pucks with a plastic mallet, ran them through the coffee grinder, and screened the results. I got about 30-40% dust and the grains were still very soft if not a little more dense than riced. I shot some of this and it was ok but not what I was looking for, so back to the drawing board.
One other thing that bothered me was the long milling time required to make real dust of the meal. My tumbler setup, in a word, sucked. Not enough brass balls, brass not heavy enough, rubber drum soaked up too much energy. So I thought on it a bit and ended up using a hard, plastic, hexagonal Airsoft BB container for a drum and filled it up nearly halfway with scrap .45 ACP cast full of wheelweight metal. Then I stuck the container with all three powder ingredients and the cylindrical media inside into my SSTM tumbler, packed towels around it to take up the space, held it together with just the rubber cover, and turned it on. WOW what a difference! I had finer then ever meal (feels like motor mica between the fingers) in only eight hours.
After some exhaustive internet research I came up with several binding agents used to make hard grains. I also found out that using straight water to lightly dampen the meal before corning makes the KNO3 glue the mix together...supposedly. I tried corning the meal with water and it was not much better than alcohol and took a lot longer for the pucks to dry, so I decided that a binder would be necessary even with corning, at least at my house.
The binders I found for black powder are red gum powder, dextrin, gum Arabic, Carboxymethylcellulose, and soluble glutinous rice starch. Red gum and dextrin seem to be the choice of hobby pyrotechnicians who are just ricing their powder (not corning in a press) and don't care all that much about how clean it burns or energy density. Gum Arabic and CMC aren't used much for sporting powders and I couldn't find a lot of information about them outside of fireworks lift propellant. I finally found a source who actually made and used gunpowder bound with soluble glutinous rice starch and the report was grains hard as rocks and the burn not being any more dirty than without, at a 3% treatment. So I got some thinking all I'd have to do is rice and grade the stuff, maybe polish it, and use more to make up the lack of power at the range. Quick, easy, and simple. That was the plan.....
Well, first off, even at 2% the rice starch made the dampened ball very sticky and like clay. It didn't want to push through a screen and when it did it just made worms that stuck together even with minimal water. With great effort and screening damp I managed to produce 2000 grains of the stuff in 3 and 4F and let it dry, so I have the unexpected setback to my easy ricing process. However, grains are HARD! Haven't shot any of that yet but the 20-50 screen comes out 37.2 grains per 50 grain measure (Goex 3Fg is 53 grains at the same setting) so it's awful light. Burns like mad, so there's that.
Next I tried a new batch with 2% rice starch as a binder (added to finished meal and tumbled in the improved ball mill for another hour) and corned the jeezus out of it. Made one puck to test and it dried almost too hard to grind, breaks like glass, and makes lots and lots of useless dust when put through the coffee mill. About 50% yield of 3-4F. Lesson learned, next I pressed a puck from the meal and broke up and ground it damp, similar results in dust percentage. Obviously my particular coffee mill is the wrong tool here but I'm still learning. The good thing about breaking up and grinding the freshly pressed pucks is that I can recycle the dust immediately into the press and re-corn it on the spot, ending up with only about 5% of powder that will go back in the milled dust can and be added to the next batch of ground meal powder for corning. Happy with that but I need to improve my crushing and milling techniques to make it easier and faster yet retain my process of working only one puck at a time (about 3/4 ounce of powder in any one process from corning to finished powder container, that way if it blows up it won't hurt much as all processes are physically separated to prevent chain explosions or explosions of a large amount at once). I did a density test of the corned, damp-milled powder after the grains had dried well and it only increased to 43 grains per 50 grain volume measure. I'm within 12% of the measure but expected more. I think my charcoal is too light, this whole time I've been using the same, Red Alder charcoal that had been cooked into full submission in my retort rather than going lower and stopping sooner to retain more aromatics and creosotes. I also think overcooking the charcoal made it so it won't make hard grains even when dampened with water and corned in a press. Binders aren't supposed to be needed when corning heavily but so far this is NOT my experience.
Next step is to shoot a bunch of the corned, ground, starched powder and see how it does. If that works OK I'll continue to refine the process of making that product in those percentages easier and faster to do. If the performance doesn't improve greatly to make it worth the effort I'll next switch to experimenting with different charcoal and keep all else the same for now. Really all I have to play with is making the puck grinding more efficient and faster and experimenting with binder amounts and charcoal type/degree of cook.
Hopefully this weekend I'll have some answers.
Three simple ingredients, put it together a certain way, and presto! Gunpowder! Well, not quite. Here's what I've done:
Got some technical grade, granulated KNO2 and sulfur, a dedicated kitchen blender, a small rock tumbler, a manual coffee grinder with ceramic wheels, and some brass ball bearings. Also picked up a stackable set of grading screens in 10/20/30/40/50 and 60 mesh.
Then I took one of those sheet metal popcorn tins we all have left over from Christmas and cooked down some small ricks of Red Alder in a couple of different batches (holding at different temperatures) and some seasoned Chinaberry in another. Turned the finished charcoal to airfloat in the blender and immediately put in sealed mason jars.
First go in the little rubber ball mill canister with brass balls, I did the 75/15/10 mix by weight and let it run. After checking a few times it took about 28 hours to get dust, definitely needed improvement. So I damped the dust with 91% isopropyl alcohol until it would just start to clean the sides of the container (like making pie crust) and riced it through the 20-mesh screen. After drying, I re-screened it into 3F and 4F and did some open-air burn tests (light a line of it off) and it seemed almost as fast as Goex but didn't put off quite as strong of a pressure wave or heat blast. Riced powder never has the oomph of corned so I wasn't surprised.
I enjoyed shooting this powder in several percussion guns and my flinter rifle where it worked great but of course was pretty low in velocity compared to Goex and Graf's of the same grades. My stuff lights in the pan VERY well.
After the first go I'm left with two problems to solve: Need mo' powah and stronger granules. The riced powder kernels easily crush to dust between thumb and forefinger, will not withstand polishing, and won't work in a powder horn very well. I also suspect the kernels will revert to dust quickly in storage. Corning is supposed to fix both problems, so I tried that. 1.5" ID heavy aluminum tube with a piston turned to match was used in conjunction with a 20-ton hydraulic shop press to produce corned pucks of very high density. I used alcohol to just barely dampen the meal until it stopped making dust when stirred with a spoon in a container (just a few drops, in other words) before corning. Then I broke up the dried pucks with a plastic mallet, ran them through the coffee grinder, and screened the results. I got about 30-40% dust and the grains were still very soft if not a little more dense than riced. I shot some of this and it was ok but not what I was looking for, so back to the drawing board.
One other thing that bothered me was the long milling time required to make real dust of the meal. My tumbler setup, in a word, sucked. Not enough brass balls, brass not heavy enough, rubber drum soaked up too much energy. So I thought on it a bit and ended up using a hard, plastic, hexagonal Airsoft BB container for a drum and filled it up nearly halfway with scrap .45 ACP cast full of wheelweight metal. Then I stuck the container with all three powder ingredients and the cylindrical media inside into my SSTM tumbler, packed towels around it to take up the space, held it together with just the rubber cover, and turned it on. WOW what a difference! I had finer then ever meal (feels like motor mica between the fingers) in only eight hours.
After some exhaustive internet research I came up with several binding agents used to make hard grains. I also found out that using straight water to lightly dampen the meal before corning makes the KNO3 glue the mix together...supposedly. I tried corning the meal with water and it was not much better than alcohol and took a lot longer for the pucks to dry, so I decided that a binder would be necessary even with corning, at least at my house.
The binders I found for black powder are red gum powder, dextrin, gum Arabic, Carboxymethylcellulose, and soluble glutinous rice starch. Red gum and dextrin seem to be the choice of hobby pyrotechnicians who are just ricing their powder (not corning in a press) and don't care all that much about how clean it burns or energy density. Gum Arabic and CMC aren't used much for sporting powders and I couldn't find a lot of information about them outside of fireworks lift propellant. I finally found a source who actually made and used gunpowder bound with soluble glutinous rice starch and the report was grains hard as rocks and the burn not being any more dirty than without, at a 3% treatment. So I got some thinking all I'd have to do is rice and grade the stuff, maybe polish it, and use more to make up the lack of power at the range. Quick, easy, and simple. That was the plan.....
Well, first off, even at 2% the rice starch made the dampened ball very sticky and like clay. It didn't want to push through a screen and when it did it just made worms that stuck together even with minimal water. With great effort and screening damp I managed to produce 2000 grains of the stuff in 3 and 4F and let it dry, so I have the unexpected setback to my easy ricing process. However, grains are HARD! Haven't shot any of that yet but the 20-50 screen comes out 37.2 grains per 50 grain measure (Goex 3Fg is 53 grains at the same setting) so it's awful light. Burns like mad, so there's that.
Next I tried a new batch with 2% rice starch as a binder (added to finished meal and tumbled in the improved ball mill for another hour) and corned the jeezus out of it. Made one puck to test and it dried almost too hard to grind, breaks like glass, and makes lots and lots of useless dust when put through the coffee mill. About 50% yield of 3-4F. Lesson learned, next I pressed a puck from the meal and broke up and ground it damp, similar results in dust percentage. Obviously my particular coffee mill is the wrong tool here but I'm still learning. The good thing about breaking up and grinding the freshly pressed pucks is that I can recycle the dust immediately into the press and re-corn it on the spot, ending up with only about 5% of powder that will go back in the milled dust can and be added to the next batch of ground meal powder for corning. Happy with that but I need to improve my crushing and milling techniques to make it easier and faster yet retain my process of working only one puck at a time (about 3/4 ounce of powder in any one process from corning to finished powder container, that way if it blows up it won't hurt much as all processes are physically separated to prevent chain explosions or explosions of a large amount at once). I did a density test of the corned, damp-milled powder after the grains had dried well and it only increased to 43 grains per 50 grain volume measure. I'm within 12% of the measure but expected more. I think my charcoal is too light, this whole time I've been using the same, Red Alder charcoal that had been cooked into full submission in my retort rather than going lower and stopping sooner to retain more aromatics and creosotes. I also think overcooking the charcoal made it so it won't make hard grains even when dampened with water and corned in a press. Binders aren't supposed to be needed when corning heavily but so far this is NOT my experience.
Next step is to shoot a bunch of the corned, ground, starched powder and see how it does. If that works OK I'll continue to refine the process of making that product in those percentages easier and faster to do. If the performance doesn't improve greatly to make it worth the effort I'll next switch to experimenting with different charcoal and keep all else the same for now. Really all I have to play with is making the puck grinding more efficient and faster and experimenting with binder amounts and charcoal type/degree of cook.
Hopefully this weekend I'll have some answers.
