TheSidewinder Posted August 4, 2009 Posted August 4, 2009 You can add a couple percent Cab-O-Sil or thoroughly dry your ingredients first (or turn off the machine and whack the end until the clumps fall off. ) Personally, I've never had clumping issues, but I tend to load my mill somewhat "media-heavy" and it doesn't get a chance to clump.
TheEskimo Posted August 4, 2009 Posted August 4, 2009 I agree...my problem is too much material, and not enough media. My material is always equal to, or greater volume than my media. I must needs go on a junkyard trip.
TheSidewinder Posted August 4, 2009 Posted August 4, 2009 Well, your chems should be a larger volume than the media. I believe someone on here said about 1/3 media, 2/3 chems (both by volume) is optimal for a ball mill, but I'm not certain of that.
Mumbles Posted August 4, 2009 Posted August 4, 2009 Optimal is 1/2 jar of media, and 1/4 a jar of material.
firetech Posted August 4, 2009 Posted August 4, 2009 My bp clumps, but it doesn't seem to make a difference. I guess it clumps when its extremely fine and ready to be taken out. Like I said my bp, is extremely fast and I don't think clumping really affects it.
Richtee Posted August 4, 2009 Posted August 4, 2009 What do you mean? I use it to light stuff. You should be using commercial fuse for that. BM is basically for crossmatching and making quickmatch.
flying fish Posted August 4, 2009 Posted August 4, 2009 I actually had some problems with clumping with the mill I got from you, Rich. At one point I felt the inside of the jar with my finger...and it was damp. That mill seems to draw water to itself or somethin... One thing that seems to work was taking out the media and drying them, and the inside of the mill, prior to each run. Maybe it just has to do with where I've been storing the jar (on the floor in the garage, under a shelf).
Richtee Posted August 4, 2009 Posted August 4, 2009 I actually had some problems with clumping with the mill I got from you, Rich. At one point I felt the inside of the jar with my finger...and it was damp. That mill seems to draw water to itself or somethin... One thing that seems to work was taking out the media and drying them, and the inside of the mill, prior to each run. Maybe it just has to do with where I've been storing the jar (on the floor in the garage, under a shelf). Also, the humidity of the air can cause that. I have had trouble with that before, but drying the chems helped. Especially the charcoal, as I'd store it on concrete, and not a good container.
poisonkiller Posted August 4, 2009 Posted August 4, 2009 You should be using commercial fuse for that. BM is basically for crossmatching and making quickmatch.I would use a commercial fuse, but I am unable to order stuff (chemicals, fuses) from other countries (my own reasons). So I need a decent alternative. I'll try black match again later, with a different string and wetter BP putty. The last time BP burned cleanly off the string, leaving it intact, but from videos I can see, that the string should burn too (so maybe my string didn't absorb the BP?).
TheEskimo Posted August 4, 2009 Posted August 4, 2009 Hmmm....Poisonkiller, what kind of sting are you using? Cotton, synthetic, hemp? The type of string will affect if the string is burned with the BP or not.
poisonkiller Posted August 4, 2009 Posted August 4, 2009 (edited) Hmmm....Poisonkiller, what kind of sting are you using? Cotton, synthetic, hemp? The type of string will affect if the string is burned with the BP or not.Cotton. It absorbs water pretty well, thus it should absorb BP slurry good. That's why I'm planning to try a wetter slurry. Edited August 4, 2009 by poisonkiller
poisonkiller Posted August 4, 2009 Posted August 4, 2009 Why should the string burn as well?That way there will be less remains and it would show, that BP had absorbed into the string (if BP can actually absorb into the string, because I don't know if that's even possible).
psyco_1322 Posted August 4, 2009 Posted August 4, 2009 You should just roll yourself up some paper fuse, like what is used in firecrackers. Just get a length of ~1" wide tissue paper, lay it out on a table, and wet it down. Run a thin trail of mill dust down the center and roll up the tissue paper at an angle as if you were making tube for quickmatch. You should come out with a gray strand of fuse if you use white paper.
poisonkiller Posted August 4, 2009 Posted August 4, 2009 You should just roll yourself up some paper fuse, like what is used in firecrackers. Just get a length of ~1" wide tissue paper, lay it out on a table, and wet it down. Run a thin trail of mill dust down the center and roll up the tissue paper at an angle as if you were making tube for quickmatch. You should come out with a gray strand of fuse if you use white paper.This sounds good, I'm gonna try that tomorrow and report back.
TheEskimo Posted August 5, 2009 Posted August 5, 2009 Ahaha..I found out why my BP was clumping. The charcoal(paulownia) had been sitting in the basement. I stuck it in a 175 degree oven for about 5-10 minutes. I then milled 300 grams BP for 3.5 hours. Pulled it out, and found virtually no clumpy BP. And that kids,...... is why you use dry ingredients.P.S. Check out my Winokur 23 3 inch shell using this BP. On YouTube.
Mumbles Posted August 5, 2009 Posted August 5, 2009 My string doesn't burn away completely, but it's left as glowing embers and chunks. Some suggest soaking the string in KNO3 solution and drying prior to coating with your slurry. I've never found that necessary. It sounds to me like you're not incorporating the BP well enough, and it's just flashing along the surface. I wrap my string around a 4" PVC pipe, forming a coil. Then I dunk it in the slurry, made with hot water. I will then kneed it thoroughly, at least 5-10 min usually to get it fully incorporated. When you cut the blackmatch, you clearly see BP incorporated into the fibers and in between the windings.
andyboy Posted August 5, 2009 Posted August 5, 2009 I have a small container with dissolved KNO3/water that the string passes before it passes the BP slurry. Powder some meal over it and hang it up to dry. Never touch it with my fingers. Oh, yeah it's four strands so there is BP between the strings as well. Burns leaving only some charred residue.
psyco_1322 Posted August 5, 2009 Posted August 5, 2009 I would think that nitrate soaked strings would keep smoldering after the burn. Kind of like slow fuse, which is rope soaked in a KNO3 solution and dried, burns like 5 minutes an inch.
flying fish Posted August 5, 2009 Posted August 5, 2009 While we are talking about making fuse... I was considering crossmatches...I was thinking...why not coat paper fuse in BP slurry to obtain a "co-axial" crossmatch fuse? That way, if some BP happens to flake off, the core fuse will be there as a backup.
Richtee Posted August 5, 2009 Posted August 5, 2009 While we are talking about making fuse... I was considering crossmatches...I was thinking...why not coat paper fuse in BP slurry to obtain a "co-axial" crossmatch fuse? That way, if some BP happens to flake off, the core fuse will be there as a backup.Like you, I tried crossmatching, but got just as reliable results by splitting the end of the timing fuse and coating with NC bound BP.
lodcomm Posted August 5, 2009 Posted August 5, 2009 (edited) I actually had some problems with clumping with the mill I got from you, Rich. At one point I felt the inside of the jar with my finger...and it was damp. That mill seems to draw water to itself or somethin... One thing that seems to work was taking out the media and drying them, and the inside of the mill, prior to each run. Maybe it just has to do with where I've been storing the jar (on the floor in the garage, under a shelf). I have noticed that the black rubber "Jars" on the Chicago Machine/Harbor Freight rock tumblers seem to be hygroscopic in themselves. Anything I would attempt to mill in them would inevitably end up damp and clump up, and I observed the exact same thing as Fish: The inside of the rubber jar would be damp. I even tried drying them in a warm oven, heat gun, etc.. but no matter what after about 1/2 hour of milling, the composition inside would end up damp and clumpy. Cab-o-sil and silica-gel proved innefective. I long ago got rid of the stock rubber jars, and made up some PVC pipe which does not have the problem. -t Edited August 5, 2009 by lodcomm
Swede Posted August 5, 2009 Posted August 5, 2009 That is interesting. I actually prefer the rubber lortone-type jars for small jobs, as there are fewer crevices for chemicals to hide in and avoid being ground up. Even my very best-made PVC jars have seams internally that can trap the stuff you want to mill, and when you dump them, you have a mixed mesh rather than all fine stuff. I've never had clumping in any jar, and I do not live in a dry environment. It's actually quite humid here, DFW Texas. Are you sure your chemicals are not carrying a lot of water with them?
lodcomm Posted August 5, 2009 Posted August 5, 2009 That is interesting. I actually prefer the rubber lortone-type jars for small jobs, as there are fewer crevices for chemicals to hide in and avoid being ground up. Even my very best-made PVC jars have seams internally that can trap the stuff you want to mill, and when you dump them, you have a mixed mesh rather than all fine stuff. I've never had clumping in any jar, and I do not live in a dry environment. It's actually quite humid here, DFW Texas. Are you sure your chemicals are not carrying a lot of water with them? Yes, the chems were quite dry. I generally throw a couple dessicant packages into the tubs or containers I store my chems in, especially those that are hygroscopic. (like: http://www.adorama.com/AQU905.html). They work wonders at keeping even the most pesky chems very dry. I am not sure what was responsible for the rubber jar acting hygroscopically, I just assumed it was a fluke with my setup. I used to see more of a problem during cool/damp conditions here in CT. Like I said, the problem was persistent enough for me to stop using the rubber jars. Actually I built a separate ball mill altogether, and made some charge vessels out of pvc. I would not have any problem at all with using the exact same chems in my PVC based bottles?. I actually do still use the little chicago (2 bottle model) & rubber jars to tumble mix star compositions and such (no milling media, but sometimes I throw a handful of wood scrabble chips in there to help the mixing). -t
flying fish Posted August 6, 2009 Posted August 6, 2009 Like you, I tried crossmatching, but got just as reliable results by splitting the end of the timing fuse and coating with NC bound BP. I've been doing something very similar to that; I cut the fuse at an angle and then prime with NC bound BP. Never had a fuse fail to take fire (I did have a couple that failed to pass fire; since then I started angle-cutting BOTH ends). There are a couple applications where I thought it might be good to know how to cross-match...such as top-fused canister shells and inserts that require very precise timings. I have never made either, but those are the kinds of devices that happen to be of interest to me at the moment.
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