LiamPyro Posted June 29, 2016 Posted June 29, 2016 Hey guys, I bought some alumina media and tried using it in my 3lb mill but it not only produces sub-par BP, possibly due to it's light weight, (I also lack the correct amount, so my jar is underfilled) but it is apparently somewhat risky to use as well. What is a good source of brass/stainless steel media? Is cutting up a length of brass rod to make cylinders a good method? Also, what are other options besides lead? I've heard of lead filled copper, which seems like a great idea but time-consuming to make if you use pipe caps and pour in lead (Dagabu made some media this way if I'm not mistaken). Thanks in advance for any responses!
Nessalco Posted June 29, 2016 Posted June 29, 2016 (edited) My mill media is brass, cut from 1/2" and 3/4" rod stock. I like it a lot, as there is little wear and the milling efficiency is high. It's not cheap, as you lose a fair chunk when you saw the rod into pieces. find the thinnest kerf blade you can, and expect to spend a fair chunk of time at the job. A jig is essential, and you should catch the 'dust' - you can probably sell it back to the metals dealer. I'm fortunate to have a metals dealer in the area that will deal in small quantities. I've bought aluminum, brass, and stainless steel stock from them for years. Check the phone book, ask around, and don't hesitate to contact scrap dealers. There's likely somebody similar in your area. They're a great bunch to deal with. Besides selling stock, they do fabrication. They drilled the base (1.5" steel) and top (1" steel) of my press for $75, including stock costs. They also welded up some 4" mortars for me, with gusseted plugs. Just over $35 each, including stock. Kevin Edited June 29, 2016 by Nessalco
MadMat Posted June 29, 2016 Posted June 29, 2016 I've always wondered how bearing grade bronze would work (maybe one of the aluminum-bronzes) These alloys are very tough and wear resistant and don't let the aluminum part worry you about weight, as it's pretty heavy. The only problem would be the expense $$$
Nessalco Posted June 30, 2016 Posted June 30, 2016 pyroman - lead is good, but it wears significantly and is expensive. Brass is expensive too, but lasts much longer and provides good milling efficiency.
OldMarine Posted June 30, 2016 Posted June 30, 2016 pyroman - lead is good, but it wears significantly and is expensive. Brass is expensive too, but lasts much longer and provides good milling efficiency.If you get lead alloyed with antimony and hardened it will last a long time. I've run my mill over 100 hrs and have yet to round the cut ends off. Pure lead would wear faster for sure. Shipping is what kills you on lead media.
Maserface Posted June 30, 2016 Posted June 30, 2016 Shipping is what kills the mailman, on lead media I would start with getting an efficient load, too little media / too much really kills the efficiency.
OldMarine Posted June 30, 2016 Posted June 30, 2016 I'm a plumber so I get lead for nothing. I ordered an ingot of antimony and used linotype for the bulk of my alloy and poured my second batch myself. That is absolutely NOT fun but was way cheaper than paying the shipping on the stuff.
chuckufarley Posted July 1, 2016 Posted July 1, 2016 Cast my own with linotype as well. Free shipping on 50#. I agree OM it is a pain to mold, but it was a good experience, and I know I have a hard, safe media to use. And when it starts getting too worn, I can melt it down and make new stuff. IMO it's worth the extra cost for the piece of mind. 1
LiamPyro Posted August 10, 2016 Author Posted August 10, 2016 I got sidetracked and unitentionally abandoned this topic, but I'm back with more questions. I've pretty much settled on buying a long 1/2" rod and chopping it up into 1/2" sections, but I'm torn between using brass and stainless. The stainless (304) is cheaper although lighter and maybe not as spark proof (?), brass (360) is more pricy but heavier and potentially safer, also it would also be less of a pain to cut up. I can get 84" of brass off amazon (yes, amazon. It made me cringe too) for about $47 (I would probably have left overs, which is fine), or 72" stainless for $30. That said, I'm more concerned about safety and functionality than price. Anyone have experience with stainless steel media? Any thoughts on which metal is superior? Nessalco has me leaning towards brass, but I want more input before I complete my decision.
DavidF Posted August 10, 2016 Posted August 10, 2016 LiamPyro, I have used ceramic, 260 brass, and 304 stainless steel, and lead in various setups. I am currently experimenting with small stainless steel media for milling both charcoal and potassium nitrate. I won't bore you all with more details at this point. My focus is to make black powder that meets or exceeds the performance of commercial black powder without milling complete black powder. I use single component milling only. The components are screen-mixed twice through a 40 mesh screen. It is then good mill dust. It is as good or better than Goex. You say you are using a 3# mill. The other answers seem to be based on much larger mill jars, and do not apply to a 3lb rubber jar. My most recent experiments focus specifically on using a 3lb jar and a Lortone rock tumbler, modified to run at 75 RPM. I am working to prove or disprove oft-repeated statements about milling charcoal and black powder by replacing general statements with specific results. My tests have shown that a good charcoal such as willow, passed through a window screen, can be effectively milled alone in 50 gram quantities with stainless steel media in 3/16", 1/4", and 5/16" sizes. I'm milling the charcoal to impalpable dust, using a 6 hour mill cycle.The actual baseball flight time tests for the two smallest sizes are not in yet. The potassium nitrate is a bit tougher to mill completely in such a small jar. If the media is larger than 3/8", the efficiency drops off. I only mill the nitrate for 2 hours though. So, with 8 hours of total milling time (with no risk of explosion), you can produce 300 grams of excellent black powder- better powder than if you milled it all together. I mentioned it somewhere else, but here's where I got some of the 304 stainless steel media:https://www.craigballsales.com/aisi-304-stainless-steel/ The service was excellent.I would recommend the 5/16" balls at $3.77/100pcs. 7 units is $26.39, and will half fill your jar. No contamination, no media wear, no labor spent producing media, cheap, no risk of explosion, what's not to like? 2
LiamPyro Posted August 10, 2016 Author Posted August 10, 2016 Thanks for the lengthy response. What I don't understand, is how could powder made from individually milled components outperform powder that is milled altogether? Have you done side by side comparisons, or are you just comparing it to commercial powder? Also, a video of your powder would be really cool to see. I may seem skeptical, but it's because you have piqued my interest.
DavidF Posted August 10, 2016 Posted August 10, 2016 Everybody is skeptical, I'm used to it The key is the supermilling of the charcoal. This cannot be achieved with large media. Everybody uses large media, so how would anybody ever find out? Very few believe in pre-milling charcoal- because they used large media, and saw little benefit. 'They' includes me All ball-milling literature suggests that media must be big enough to 'bash' the feedstock to bits. This is simply not true. I only tried the tiny (5/16") media because it was sent to me as a gift to try. I did not come up with this on my own. No, I spent years spinning my wheels with large media like 5/8" to 3/4". I realize that I am the ONLY one to have been lucky enough to stumble upon this. But soon there will be 2, then 3... I am having serious computer issues and I have not been able to edit anything for a while now. It's been pen and paper for me lately, and a stopwatch. What kind of video are you thinking of? I can make a baseball stay in the air for 10 seconds with 10 grams of corned 2FA size. Screen-granulated stuff= 11 seconds. I've been busy with the stopwatch and not using the video lately. The underlying theory that I currently have is that in 3 component milling, the potassium nitrate acts as a diluent that prevents the charcoal from reaching its full potential. Using the recommended media is the other impediment. Remove these 2 things and your charcoal can shine! 1
LiamPyro Posted August 10, 2016 Author Posted August 10, 2016 I've never done baseball tests, but 11 seconds flight for 10g powder seems really good. The KNO3 diluting the charcoal makes a lot of sense and is something I never thought about, as the particle size of KNO3 reduces slower than charcoal, so it would almost "block" the media from grinding the charcoal extremely fine if I understand correctly. I'm actually completely sold on the whole idea, and will give it a try (I already have willow charcoal, all I need is the media). I will post my results.
Fulmen Posted August 11, 2016 Posted August 11, 2016 Stainless might be spark free, but that's only part of the issue. I fear it's hard enough to cause point ignition. David might have had good results, but one source isn't a lot to base this on. Lead and brass has been used for decades without incidents.
DavidF Posted August 11, 2016 Posted August 11, 2016 Stainless might be spark free, but that's only part of the issue. I fear it's hard enough to cause point ignition. David might have had good results, but one source isn't a lot to base this on. Lead and brass has been used for decades without incidents. Fulmen, are you saying that the stainless media might ignite the charcoal? Or are you saying it might ignite the potassium nitrate? Did you miss everything I said about NOT milling complete black powder? I ask: one source isn't a lot to base what on?
Fulmen Posted August 11, 2016 Posted August 11, 2016 David: My bad, I misread your post. I thought you were milling BP with stainless media, and even if you did, your experience alone isn't enough to conclude that it's safe. For milling individual chemicals stainless will of course be completely safe. I must say your work intrigues me, although I'm having trouble believing it. It would be interesting to see your premilled&mixed powder compared to milled BP (using same setup and ingredients). I assume you're pressing and corning like regular BP?
DavidF Posted August 11, 2016 Posted August 11, 2016 (edited) I realize that my credibility is suspect due to the unusual nature of my claims, and the lack of any substantive evidence to back them up. I would have hoped that my past original work would help make my claims more believable, but I'm a realist. I have milled black powder in full size batches with the stainless steel peas (5/16"). It was excellent. I never thought to do an actual comparison between my screen-mixed stuff and 3 component-milled stuff, for 2 reasons. Firstly, the results were so good right out of the gate I didn't think it was necessary. Secondly, the whole idea here is to make excellent black powder without the danger of milling black powder! Next week I will be getting a new computer. It is already on order. Then it will be time for show and tell. In the meantime I am doing more testing. I will have plenty to show you guys. I do not mind skepticism. The most brilliant man I know says that any sound hypothesis should be able to stand up to robust criticism. I am mentioning this stuff here on APC instead of on Passfire or Fireworking.com because I feel that hobbyists with nowhere to mill safely could really benefit from single-component milling- IF the final product is good. Edited August 11, 2016 by DavidF
DavidF Posted August 11, 2016 Posted August 11, 2016 I am pressing and corning, yes. But I have also screen-granulated with excellent results. I'm sure that's the route most would take. But for proper apples to apples testing, I am using pucked and corned 2FA size grains.
Fulmen Posted August 11, 2016 Posted August 11, 2016 Don't worry, I won't demand third-party testing in order to believe it, your word is good unless proven otherwise. It's just hard to believe one can make good BP this way. As I said, a comparison between regular milled BP would be very useful to judge just how close you can get. But for pyro you really don't need commercial powder, I have always used CIA-powder with good results.
NeighborJ Posted August 11, 2016 Posted August 11, 2016 DavidF I feel that your theory of the smaller media holds water. The first batch of bp I ever made was milled separate with the use of nickles. I know it sounds crazy but it worked. I believe the charcoal can be milled so much finer by itself then it ever could as a mixture. The tiny media is one method, but using nickles, I believe that it is the scraping action of the faces which allows more surface area to be milled faster and finer than any other kind of media out there. Not to mention if it shows signs of wear I can take it to the bank and exchange them for new. I've been trying to use normal media in an attempt to replicate those results, as suggested by all posts, however I can't ever get it quite as fast as the first batch. I had assumed it was due to overcooked or under cooked charcoal but I was never able to nail it down until now. I will conduct my own experiment milling with the nickles again but I believe you stumbled on the answer to the super fast bp.
Fulmen Posted August 11, 2016 Posted August 11, 2016 I think that this will be replicated quite fast. If not by any others then I will for sure. But I think we will need more details on the process. You're using a 3" jar? Size/volume? And do you just screen in the sulfur? Pre-milled or flower? Have you tried milling it together with the charcoal? As for milling KNO3 you could try 1% of charcoal as an anti-caking agent. It's not enough to constitute an explosive mixture and it does make a much more free-flowing product.
NeighborJ Posted August 11, 2016 Posted August 11, 2016 (edited) My experiment is already being milled. I have bp mill dust already milled with sumac charcoal(6hr). I've taken two 100g samples and put them each in separate drums on the same mill, one with nickels and one with my normal brass media. Once this is milled for 6 hrs I will remove it and start a new batch of just charcoal. Again one with nickels and one with brass for 6 hrs. I will then mix in kno3 and sulfer then mill for another 6 hrs. Charcoal comes from the same retort run.This will give me 5 samples to test. To test I plan on launching baseballs and pressing spolettes and tissue paper burns. All results will be videotaped and timed. All testing will be done with mill dust. Edited August 11, 2016 by NeighborJ
OldMarine Posted August 11, 2016 Posted August 11, 2016 I'm thinking of getting me another little HF mill just so I can get in on some of this 'sperimentin'too! I'd love to be able to make good powder without having to trek to my brother's little farm. Individual chems would be ideal!
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