ubiwca Posted January 16 Posted January 16 Hi All! My question maybe dumb, but im stuck a bit trying to make a known BP substitute - crimson powder, consisting of potassium nitrate, ascorbic acid and iron oxide. My problem is that my workshop is in my house and i dont have possibility to move it some other place, since we are living pretty tight here. So i decided to mill ingredients separately and then mixing them. After milling and screening components through a very fine mesh(~25 microns) i mixed my first batch using my ball mill - basically, just a PVC jar with a lead balls in it. Resulting meal was burning fast! But, since my workshop located in a house, i wasnt feeling myself comfortable, while closed jar with explosive material and a lead balls was rotating behind a wall. So i decided to try to screen-mix components. I used a screen with with something about 35-37 mesh, run hand premixed components through this mesh several times. But resulting mix burns really slow! I took a bit of this mix and mixed it a bit additionally with a pestle in a mortar, for maybe 30 secs or even less, burn rate enhanced greatly and this makes me think that either i dont understand something about screen mixing, either something wrong with my techninc. Pyrotechnics is not really a common hobby in my country(even with respect to the fact it is legal), so i wasnt able to find someone experienced to get a consultation and decided to seek for help online. So, i have following questions: 1. Is it safe enough to mix BP and similar mixes(like crimson powder) using a PVC ball mill with lead balls? 2. Do i understand correct, that screen mixing means sieving of hand mixed components through a mesh screen and only this? And im not missing some steps? Or maybe my screen was to big? 3. If answer to 1 is no, can you recommend me a safe way for mixing pre-milled ingredients?
Sulphurstan Posted January 16 Posted January 16 Even if I have plenty of place to potentially ballmill bp, I have always milled my components separately, and the burning speed of resulting green mix is ok for my needs. Ballmilling fuels and dextrin on one side, then KNO3 on the other side, and then screen mixing (Q. 2: screen mixing is: you put all the components together, and pass them through a screen SEVERAL times, again 'n again). Mesh size isn't that important, important is the again 'n again!:-) Q3. Screen mixing dry compositions are relatively safe IMHO (except flash or other dead mixes like Armstrong). Maybe it is useless, but I always ground myself and the sieve during screen mixing, and wear cotton clothing, no wool, and no synthetics. Anyway for BP I don't screen mix, but wet mix and then granulate.
cmjlab Posted January 16 Posted January 16 I'm sure many people would disagree with me, BUT, before I invested in a ball mill, I tried the "CIA" method and made reasonable B.P. (if you could actually call it Black Powder). If your interested, I believe CIA stands for Cold Isopropyl Alcohol Method. There should be some descriptions of you Google it. Just another suggestion for your consideration if you can't ball mill your B.P. together.
Crazy Swede Posted January 17 Posted January 17 ubiwca, aren’t you satisfied with the answer you got on Reddit? ”Screen mixing on 40 mesh is usually effective but dry mixing still expose you to the cloud of fire if you would have an accidental ignition. You need good personal protective gear for that. Wet mixing can be done in a lot of ways but the safest ones are manual. Start in small scale to get amounts and techniques right. First I would premix the iron oxide with the potassium nitrate dry in the ball mill. Let it run for several hours! This is completely safe. Then I would test with moistening of the nitrate/oxide pre-mix with a 50/50 mixture of water/ethanol until a thick soup. Add the ascorbic acid and work the mixture heavily in a bowl with a wooden spoon or similar. The mixture must not be too dry since you must be able to stir it. After thorough mixing you spread it onto plastic food wrap and let it dry somewhat until the consistency allows you to rub it through a screen without clogging it up too much. A 40 mesh screen is usually too fine for this. Take a 20 or 30 mesh screen. It might take a long time to dry!”
Zumber Posted January 17 Posted January 17 13 hours ago, ubiwca said: Hi All! My question maybe dumb, but im stuck a bit trying to make a known BP substitute - crimson powder, consisting of potassium nitrate, ascorbic acid and iron oxide. My problem is that my workshop is in my house and i dont have possibility to move it some other place, since we are living pretty tight here. So i decided to mill ingredients separately and then mixing them. After milling and screening components through a very fine mesh(~25 microns) i mixed my first batch using my ball mill - basically, just a PVC jar with a lead balls in it. Resulting meal was burning fast! But, since my workshop located in a house, i wasnt feeling myself comfortable, while closed jar with explosive material and a lead balls was rotating behind a wall. So i decided to try to screen-mix components. I used a screen with with something about 35-37 mesh, run hand premixed components through this mesh several times. But resulting mix burns really slow! I took a bit of this mix and mixed it a bit additionally with a pestle in a mortar, for maybe 30 secs or even less, burn rate enhanced greatly and this makes me think that either i dont understand something about screen mixing, either something wrong with my techninc. Pyrotechnics is not really a common hobby in my country(even with respect to the fact it is legal), so i wasnt able to find someone experienced to get a consultation and decided to seek for help online. So, i have following questions: 1. Is it safe enough to mix BP and similar mixes(like crimson powder) using a PVC ball mill with lead balls? 2. Do i understand correct, that screen mixing means sieving of hand mixed components through a mesh screen and only this? And im not missing some steps? Or maybe my screen was to big? 3. If answer to 1 is no, can you recommend me a safe way for mixing pre-milled ingredients? 1. Ball mill must be operted in remote area if you dont have such place you probably stop using it in your house. Insted you can operate it for just milling individual material ( for this work coffee grinder works too) 2.yes screening means mixting all ingredients closely. Degree of mixing affects burn rate,if you mix bp in 30 mesh screen and if you change mesh size like 100 mesh screen then you will see big difference in burn rate. Your screen seems big youmight switch 60 or 80 mesh for mixing. Friction sensitive mixture must not be screened insted it should be mixed By diaper mixing methods. 3.I have no experience with crimson powder, but for bp if you dont have remote place for ball mill just grind kno3 using coffee grinder so that you get 100 mesh plus finer powder then mix charcoal and sulphur using 80 or 100 mesh screen 4 times. Another way is just damp mixture and knead it dont make slurry or dont make too damped mixture Consistency should be just like damped rolled stars, then mix it using morter and pestle and dry out mixture in sun then screen in again to get powder form.
ubiwca Posted January 17 Author Posted January 17 9 hours ago, cmjlab said: If your interested, I believe CIA stands for Cold Isopropyl Alcohol Method. I have tried that method. It doesnt works for crimson powder, result is almost not combustible. Not sure why, though. 10 hours ago, cmjlab said: Just another suggestion for your consideration if you can't ball mill your B.P. together. I can, but im a bit worried about this process safety, thats why im looking for alternatives. 4 hours ago, Crazy Swede said: ubiwca, aren’t you satisfied with the answer you got on Reddit? No, this answer doesnt contain anything i didnt tried yet. 4 hours ago, Crazy Swede said: Then I would test with moistening of the nitrate/oxide pre-mix with a 50/50 mixture of water/ethanol until a thick soup. Add the ascorbic acid and work the mixture heavily in a bowl with a wooden spoon or similar. The mixture must not be too dry since you must be able to stir it. I have tried similar method. Result is much better than a simple screen mixing, but slower than a mixing in a ball mill.
ubiwca Posted January 17 Author Posted January 17 23 minutes ago, Zumber said: Insted you can operate it for just milling individual material That is how im currently using it - to mill individual components. 23 minutes ago, Zumber said: Your screen seems big youmight switch 60 or 80 mesh for mixing. Hmm, good point, will try my smallest screen today.
Crazy Swede Posted January 17 Posted January 17 Screen mixing through screens as fine as 60 or 80 mesh is a struggle and will inevitably create more friction and therefore a higher risk. If your previous attempts with wet mixing was a failure I believe you might have been working the mixture for too short time, maybe used too much water, used a too coarse screen or simply did not dry the granules properly. Remember ascorbic acid is hygroscopic and you probably must dry it at 80 degrees C or higher over night to really get it dry. (DO NOT DO THIS INDOORS!) It might be best to wet it with ethanol only in a wet mixing process! You could also try to ball mill half of the iron oxide with the potassium nitrate and the remaining half of iron oxide with the ascorbic acid. That could improve burn rate both after dry or wet mixing.
ubiwca Posted January 17 Author Posted January 17 29 minutes ago, Crazy Swede said: It might be best to wet it with ethanol only in a wet mixing process! This will prevent dextrin im using for a granulating purposes from been sticky, so im using 25% alcohol. 34 minutes ago, Crazy Swede said: If your previous attempts with wet mixing was a failure I believe you might have been working the mixture for too short time, maybe used too much water, used a too coarse screen or simply did not dry the granules properly. Yeah, something of this is definetely possible, im planning to continue my experiments with wet mixing. 35 minutes ago, Crazy Swede said: Remember ascorbic acid is hygroscopic and you probably must dry it at 80 degrees C or higher Drying small batch right now in PID controller electric oven at 60C to see if it will help.
Arthur Posted January 17 Posted January 17 Some people have a legitimate retail source of BP in all the commercial grades, first check whether you can buy the powder you really want, you may need a permit or licence. If the powder is available then getting a permit is the easy way of getting powder. A mill shouldn't be run in a home. Go find a place where you can safely work, as you say home is a small place, one mill blast could harm several people -it's not worth the risk.
ubiwca Posted January 17 Author Posted January 17 12 minutes ago, Arthur said: If the powder is available then getting a permit is the easy way of getting powder. Not available at all. I have a firearm permit, so, technically, can buy any types of gunpowders for reloading purposes, but BP is not imported anymore for many years.
Arthur Posted January 17 Posted January 17 (edited) In which case consider getting an inverter and a battery and moving out to some woods for a day Make some charcoal from fallen sticks, and mill some powder with last time's charcoal. Noisy, smelly and hazardous tasks are best done away from people and prying eyes. Consider getting a solar panel to power an "out in the woods" powder making session. Edited January 17 by Arthur
Zumber Posted January 17 Posted January 17 2 hours ago, ubiwca said: I have tried that method. It doesnt works for crimson powder, result is almost not combustible. Not sure why, though. I can, but im a bit worried about this process safety, thats why im looking for alternatives. No, this answer doesnt contain anything i didnt tried yet. I have tried similar method. Result is much better than a simple screen mixing, but slower than a mixing in a ball mill. CIA method is only for black powder in which dissolved kno3 is mixed in charcoal pores.
Zumber Posted January 17 Posted January 17 2 hours ago, Crazy Swede said: Screen mixing through screens as fine as 60 or 80 mesh is a struggle and will inevitably create more friction and therefore a higher risk. If your previous attempts with wet mixing was a failure I believe you might have been working the mixture for too short time, maybe used too much water, used a too coarse screen or simply did not dry the granules properly. Remember ascorbic acid is hygroscopic and you probably must dry it at 80 degrees C or higher over night to really get it dry. (DO NOT DO THIS INDOORS!) It might be best to wet it with ethanol only in a wet mixing process! You could also try to ball mill half of the iron oxide with the potassium nitrate and the remaining half of iron oxide with the ascorbic acid. That could improve burn rate both after dry or wet mixing. I have already mentioned friction sensitive components is not mixed with 60 or 80 mesh screen This is just only for black powder composition. As passing through 60 /80 mesh is struggle therefore kno3 is previously grinded into 100 mesh plus fine powder using coffee grinder or it is ball milled before screening. Sulphur and charcoal readily passes through 60 mesh.
ubiwca Posted January 17 Author Posted January 17 1 hour ago, Zumber said: I have already mentioned friction sensitive components is not mixed with 60 or 80 mesh screen This is just only for black powder composition. Yeah, but crimson powder also not friction-sensitive. As option im thinking about using a silkscreen im using to screen components after milling. There are some residues left after burning samples from last batch(screened and wet mixed ), which make me think that components incorporation during mixing isnt that great.
Zumber Posted January 17 Posted January 17 I dont have experience with crimson powder. What you want to do? Are you trying to prepare propellent?
ubiwca Posted January 18 Author Posted January 18 15 hours ago, Zumber said: Are you trying to prepare propellent? Yeah. Ballmill-mixed propellant shows quite promising results, although i wasnt able to do a range test on a real gun, because range is under 1 meter of a snow 😅. So while im waiting for a better weather, my current goal is to develop a safe method of mixing components with same results.
Zumber Posted January 18 Posted January 18 Insted of crimson powder you might focus on black powder propellent. For good quality black powder considers following factors. 1- purity of raw material Kno3 must be highly pure Sulphur is of good quality Type of charcoal affects a lot 2-degree of mixing This is most important factor responsible for burn rate 3-particle size of individual material Finer mesh raw material improves burn rate a lot Wet bp with water and knead it to form thick consistency material and use morter and pestle to mix it.
Zumber Posted January 18 Posted January 18 I have another method for those who dont have access to ball mill I will start a new topic today.
ubiwca Posted January 18 Author Posted January 18 24 minutes ago, Zumber said: Insted of crimson powder you might focus on black powder propellent. Yeah, i thought about it already, especially because it will allow me to use CIA method, but still hope i will be successful with crimson, since it has some advantages and i also have some kilos of ascorbic acid available. 54 minutes ago, Zumber said: Finer mesh raw material improves burn rate a lot Yeah, im screening pre-milled components through a 25 microns silkscreen, this really helps. 56 minutes ago, Zumber said: I will start a new topic today. Will wait, thank you!
ubiwca Posted January 18 Author Posted January 18 9 hours ago, Zumber said: I have posted topic what method I use for BP. Yes, im reading it right now, thank you!
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