taiwanluthiers Posted June 16, 2012 Posted June 16, 2012 I have no idea what is good, I just know mines burn like road flares, as in when the usual recipe is used I get a medium gray powder rather than black, and when I lay down a 2" line it takes about 4 or 5 seconds to finish burning. I made it in small test quantities (10 grams or so) with a mortar and pestle so I don't know if its because I didn't mix it enough. It works fine for blackmatch though.
Potassiumchlorate Posted June 16, 2012 Posted June 16, 2012 Well, it often is more grey than black. The name "black powder" was actually coined in the USA in the late 19th Century to distinguish it from the new smokeless powder. The reason it's called "black" is that it was usually polished, so that it had a black looking surface.
genrege Posted June 16, 2012 Posted June 16, 2012 @taiwanluthers - I also got my air float from a UK source, so probably the same one as you. I've read that BBQ charcoal is pretty poor, my contain clay, and when you grind it down the particle size you're likely to get with a pestle and mortar is going to be a bit on the big side. I'm hopeful for you that the air float will make a huge difference. Fyi, i used a large rough surfaced pestle/mortar, and ground the mixture against the walls in a circular motion. From time to time, I'd brush the powder stuck in the ridges with an artist's paintbrush before grinding some more. 20 minutes of this and all was good. Also used a cheap 200g/0.01g electronic scale from ebay to measure out the components in a 75:15:10 ratio as accurately as I could (I'd expect 1-2% error on the scales and they need 30s to warm up and measure reasonable accurately).
taiwanluthiers Posted June 16, 2012 Posted June 16, 2012 The charcoal I was using wasn't mixed with clay for sure, because it looked like wood when its out of the bag (the ones mixed with clay are pressed into some kind of a pellet, I am not sure why they mix it with clay). I just know that the one I got burned and left a bit of a white residue (I use a brick as a testing surface). All is not lost though, as I can still use the BBQ charcoal as some kind of a coarse sparking agent. I got it to as fine as I could with a mortar and pestle, it wouldn't get any finer and I had been milling (grinding against the sidewall) long enough to make my hands sore. I am having some kind of an idea of using a threadmill as a power source to roll the ball mill drum, but since I do not have one, the only thing I have that resembles a threadmill is a stationary belt sander, but the problem is that the belt spins very fast, too fast to be useful as a ball mill driver.
Mumbles Posted June 16, 2012 Posted June 16, 2012 There are suitable motors in a lot of old appliances and machinery. Things like higher powered fans, drill presses, evaporative coolers, washing machines and driers (can be tricky to wire), scooter motors, etc. If you look around, you should be able to find one without too much trouble I would imagine. Where there's a will, there's a way. The one thing I really hate seeing is power drills. They're not meant to run continuously or with a load on them, plus many are DC motors which will spark. All of those combined would make me very nervous for my safety and longevity of the machine. All of my powdered meal comes out a dark grey color. It's not until I wet and granulate or corn it, does it really take on a shade I'd consider close to black. It sounds like you're well on your way to making good BP genrege. A good ball mill with allow you to make larger quantities in more consistent batches IMO. Your arm will start to thank you as well.
taiwanluthiers Posted June 16, 2012 Posted June 16, 2012 I think I found someone selling an old 1/4 HP motor for 20 dollars.. I think that will cut it. In the meantime, I was playing around with a (probably stupid) idea: I take the milling jar full of media and roll it on the ground or something. Like when I am working on something I place the jar at my feet and just keep rolling it around for hours. Could be good exercise. Of course I don't want a pipe bomb on my feet so obviously I will not do a 3 component milling, only mill charcoal and sulfur together then mill a non-combustible bp mix (Potassium nitrate with VERY little charcoal, 10% of what it should have) and screen the two together. In fact I will probably never do a 3 component milling because I simply cannot afford to have an explosion, however small the chance of it is!
bob Posted June 17, 2012 Posted June 17, 2012 Hi All, Last night I too made my first batch of BP. I made about 10g, using a pestle and mortar and high quality ingredients from a reputable pyro supplier. I ground the materials for about 20 minutes and took a small sample to test. I made a thin line of BP about 2 inches long, lit it, expecting to see it fizzling along, but in fact, it all went up at once. I *think* subjectively that I made some good BP, but this obviously begs the question as to how I test the stuff to determine its quality. Do you guys have a standard method? I'm making some small grains out of what's left, will try that out when it's dried. BTW thanks for all the info on this forum, it's absolutely great! you should try the spoolette test it's quite quick first take a 1/4 inch ID cord bored tube about 2.5 cm long and ram 1.5 mm of black powder in 5 increments make sure you give it at least 6 good hits with your rubber headed mallet (use doweling for your rammer)if you get 1.5 seconds it's ok if you get it in under a second it's really good if you get half a second you did not ram it hard anoff bob
genrege Posted June 20, 2012 Posted June 20, 2012 I tried the two tests suggested above. The 1g BP burned in what looks like more than 0.16s, so some work to do here. The spolette I tried also, was 2.5 inches long, 0.3 inches ID (i.e. a Bic biro dowel!) and this turned into a rocket that chased me round the garden! Certainly took longer than 1.5s to burn!Here's the video I took to record this fiasco: http://youtu.be/4OboOAIhHMQAny suggestions to improve the BP most welcome!
taiwanluthiers Posted June 21, 2012 Posted June 21, 2012 I am not sure if spoulette is a good way to test powder quality, because if you pack even poor quality powder loosely it will burn fast. Congratulations, you've just made a rocket. Now you can take it and attach a stick to it. I would think for real spoulettes I would want to use a slower burning composition.
Mumbles Posted June 21, 2012 Posted June 21, 2012 I would agree, but the whole idea behind a spolette is that you don't pack it loosely.
dagabu Posted June 21, 2012 Posted June 21, 2012 I am not sure if spoulette is a good way to test powder quality, because if you pack even poor quality powder loosely it will burn fast. Congratulations, you've just made a rocket. Now you can take it and attach a stick to it. I would think for real spoulettes I would want to use a slower burning composition. I use three different fuelss for spolettes, commercial 7FA for smaller shells where I want a tall BP column so that the charge doesn't get blown out upon lift. I use 116 Fuse Powder for larger shells so that the BP column is nice and short and whistle for... Whistle! Fast BP is great for small shells with short timings! -dag
bob Posted June 21, 2012 Posted June 21, 2012 I"ll be making a spollet for a test soon and I'll weigh how much I use so you can weigh the same amount out yeah you have to use a lot of tape and tape it to a brick or somthing so it does not turn into a rocket bob
genrege Posted June 21, 2012 Posted June 21, 2012 Hey Bob, look forward to hearing your results. Fyi, my test was with meal powder rather than pulverone. Let me know which you use and I'll try to copy your test as closely as I can.
bob Posted June 24, 2012 Posted June 24, 2012 (edited) ok so I did a test and weight how much I put in so it was a little diffrent 15 mm as before (after reading my post I see I said 1.5 mm ) any way I did it in 3 increments this time 6 grains or 0.388794 grams for each increment for a total of 18 grains or 1.16638 grams and sixs hits with my rubber malet and it burnt in 1 second bob Edited June 24, 2012 by bob
genrege Posted June 27, 2012 Posted June 27, 2012 Just tried it, 1/4 inch diameter, 1.5 inches long spolette, hammered in quite hard in about 6 increments. I didn't weigh the BP. Took about 3-4 seconds to burn itself out. Not very scientific, just a basic test that seems to imply I need to rethink my BP making process.
bob Posted June 27, 2012 Posted June 27, 2012 so you have 1.5 inches of rammed black powder? ok cause if that is what you are using then I would be getting 2.53933 seconds. cause I use mm not inches but 1.5 inches is = to 38.09 mm bob
Mumbles Posted June 27, 2012 Posted June 27, 2012 Genrege, something a little more accurate would be helpful, but it sounds like good powder to me. A 1" column of BP typically burns for around 2.5-3 seconds. A stopwatch, and a decent idea for the actual length should get you a more reliable value, but it sure sounds like you're right in line to me.
Potassiumchlorate Posted June 27, 2012 Posted June 27, 2012 It's the same speed as mine, but reading what some other people achieve with their powder, one becomes a bit jealous.
genrege Posted June 29, 2012 Posted June 29, 2012 I did a more scientific test of my 75:15:10 BP this evening. I took a bit more care over the measurements, and got a burn rate of 9.4mm/s (0.37 in/s) which is in line with Mumbles' figures, though a little short of Bob's. Videoed it for posterity ;-) : http://youtu.be/aNd5wYz9GHA Full details are: Spolette, 6mm (0.235in) inner diameter, length of BP column 37.7mm (1.576"), volume 2.26cm^3Weight of paper spolette, 0.55g, loaded weight 2.06g=> BP weight 1.51g and BP density 0.66g/cm^3Burn time, 3.9s, burn rate 9.4mm/s (0.37 in/s)BP hammered into spolette in 8 increments I think all in all, I'm pretty happy with this, especially as it's a pestle/mortar job. I don't like the idea of a ball milling (lead poisoning, destroying the shed, what will the neighbours say?), and UK law won't allow me to make much more quantity of BP! Now I need to find a project to apply my meagre BP supplies to! Hopefully this post will be useful for someone else wanting to test and compare their BP performance.
bob Posted June 30, 2012 Posted June 30, 2012 (edited) yeah that is pretty good charcoal and milling or in this case long mortar grind time is the key to good bp a small bp cannon is great fun and does not take much bp to make a good bangI have to say nice job man that's the way to do it write every thing down when testing the more details the betterbob Edited June 30, 2012 by bob
Mumbles Posted June 30, 2012 Posted June 30, 2012 The density seems really low, but everything else is in line so who knows? I've never weighed a spolette so I don't have anything to compare against.
yvariro Posted July 4, 2012 Posted July 4, 2012 Hi all, I read the first page of this topic, and i have a doubt because I put all chemicals in my ball mill (KNO3,C,S) when i'm making BP,it's dangerous ? I was thinking this technics was safe for making my BP, So that no safe ? there is a chance of ignition ? ( I'm new to this forum and french too,that why my english is'nt very good )
Potassiumchlorate Posted July 4, 2012 Posted July 4, 2012 Bonjour, monsieur! There is always a small but existing risk that a ballmill might explode. I would say that with non-sparking media, like brass etc, this risk is like one in a million or so.
taiwanluthiers Posted July 4, 2012 Posted July 4, 2012 I realize that I am probably more likely to get hit by a car in Taiwan (which is actually a very high chance since drivers are reckless here) than to have a ball mill explode, but I don't know it just feels dangerous to mill all 3 components at once. I did a 2 component mill and the bp I get seems no faster than if I ground it with mortar and pestle for about 15 minutes, but this is just meal powder. I have wetted it and made pulverone out of it (ricing it through a screen), hopefully this will make faster powder... I am using willow charcoal so at least the charcoal is out of the equation.
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