butch Posted November 3, 2012 Posted November 3, 2012 I was ballmilling a pound of powder (75-15-10) the other day for 4 hrs. When i took the top off i noticed that all the powder was stuck in one end and the lead balls in the other. What would cause this to happen?
taiwanluthiers Posted November 3, 2012 Posted November 3, 2012 could be moisture. You need to shake up the jar every now and then to break it up. Charcoal is particularly susceptible for this. It helps to oven or sun dry the chemicals before milling.
dagabu Posted November 3, 2012 Posted November 3, 2012 Yes, it's moisture. Dry your charcoal and chems before milling them or this will happen every time. If you have a PVC ball mill, listen for the sound change, it will get loud and "bright" sounding when the BP is packing against the walls. For this reason, I pretty much limit my milling of BP to the cooler months when the humidity is below 30% and the temp is below freezing. 45 minutes later, I have very finely ground BP. -dag
Algenco Posted November 3, 2012 Posted November 3, 2012 Yes, it's moisture. Dry your charcoal and chems before milling them or this will happen every time. If you have a PVC ball mill, listen for the sound change, it will get loud and "bright" sounding when the BP is packing against the walls. For this reason, I pretty much limit my milling of BP to the cooler months when the humidity is below 30% and the temp is below freezing. 45 minutes later, I have very finely ground BP. -dag that's most of the year in the frozen Nort isn't it?
bob Posted November 3, 2012 Posted November 3, 2012 were I live you can easly get frezzing temps for about 8 to 9 monthsAdam
dagabu Posted November 3, 2012 Posted November 3, 2012 that's most of the year in the frozen Nort isn't it? About 6 months are winter up here, November through April. Great weather if you like cold, sucks if you are a sun worshiper. -dag
butch Posted November 3, 2012 Author Posted November 3, 2012 (edited) Thanks for the info. Edited November 3, 2012 by butch
dynomike1 Posted November 4, 2012 Posted November 4, 2012 I wished that was the only problem i had.I just milled a batch of 75-15-10-+1 humidity 51 percent. Ben milling for about 17 hrs. incl. time change tried to burn some and couldn't hardly get to light when it did it didn't want to burn i just cant figure it out. Looks like the more i try the worse it gets.
AirCowPeacock Posted November 5, 2012 Posted November 5, 2012 ...are you sure you have the right chemicals..? Even green mix burns well...
Mumbles Posted November 5, 2012 Posted November 5, 2012 With very fine meal directly from a mill jar I too have issues getting it to light. In my mind the particles are so fine that they're acting more like a fluid. They spread the heat around and provide no sharp corners to light on fire from. With enough time (or a torch), the test pile will light and usually burn up in an instant with a small thump type sound.
AirCowPeacock Posted November 5, 2012 Posted November 5, 2012 Interesting, Ive never had an issue lighting my mill dust, I only mill 3h or 6h though--how long do you mill?
Mumbles Posted November 5, 2012 Posted November 5, 2012 4hr in a Sponnen mill. 12hr in a harbor freight mill. This happens to me when trying to light with a match or lighter. A more forceful flame, such as from a torch, will light it right away. The softer or more passive flame doesn't seem to light it as easily.
taiwanluthiers Posted November 5, 2012 Posted November 5, 2012 I use a lit incense to light mill dust. In my experience more reactive charcoals like willow and paulownia will light with minimal effort while less reactive charcoal like lump bbq have more difficulty lighting. I won't use a lighter to light it because I can't think of a safe way of doing it. I find mill dust to be more sensitive than granulated bp.
AirCowPeacock Posted November 5, 2012 Posted November 5, 2012 I stoped using a cigarette lighter after one to many fingertip burns.. I went and bought a torch.
dagabu Posted November 5, 2012 Posted November 5, 2012 Visco is cheap and the Chinese stuff has a really hot flame, there is no reason to be close to the BP when testing it. I use a paper cup (1 oz) or a trough with a 3" visco piece taped to the end to test mine. -dag
dynomike1 Posted November 6, 2012 Posted November 6, 2012 (edited) It stuck to the jar pretty good maybe moisture. If i dry it out maybe it will light better.I made sure i did everything right this time. Even the right chemicals. Luckley i can overcome this problem till i resolve it, i can always mill some FG. Where would i find those little packs to keep stuff dry? Edited November 6, 2012 by dynomike1
dagabu Posted November 6, 2012 Posted November 6, 2012 Mike, you may just have to tap the jar to get it off the walls every 10-15 minutes. there are many desiccants out there that work well, Damp Rid is said to work well though I don't like the idea of having liquid in my chems. I have been using silica gel desiccant bags in my charcoal and KNO3 buckets since last year after the wife bought a couple gun safe silica gel desiccant boxes on closeout. You can reheat them to drive off the water and they are good to go again. -dag
AirCowPeacock Posted November 6, 2012 Posted November 6, 2012 I use Calcium chloride for pickling. Its kind of pricy but is easily accesable, and lasts a long time, if I bake it dry before it gets too wet I will have it forever.
dagabu Posted November 7, 2012 Posted November 7, 2012 I use Calcium chloride for pickling. Its kind of pricy but is easily accesable, and lasts a long time, if I bake it dry before it gets too wet I will have it forever. I get #50 bags of it for $12.00 a bag in the off season for ice melt at work, it's the same stuff that Damp Rid. -dag
AirCowPeacock Posted November 7, 2012 Posted November 7, 2012 I spent 6$ on a pound last year. Its not as good of a deal--but I'm still using that pound.. 6$ a year is still basically free.
dynomike1 Posted November 10, 2012 Posted November 10, 2012 With very fine meal directly from a mill jar I too have issues getting it to light. In my mind the particles are so fine that they're acting more like a fluid. They spread the heat around and provide no sharp corners to light on fire from. With enough time (or a torch), the test pile will light and usually burn up in an instant with a small thump type sound. What did you with this Mumbles?
dagabu Posted November 10, 2012 Posted November 10, 2012 Its all about surface area and fire paths. You are correct that too fine a powder acts more like a fluid with a single surface to burn. Once you have the BP made into a grain, a grain size of 7FA or Meal-D (with ultra fine powder screened off) will burn violently in the open and even more so when confined to speed the propagation of flame. As the grain size increases, so does the surface area and so does the distance to the center of the grain where the fuel is completely consumed. I am not sure of the "heat sink" ability of BP in a fine particles but do agree with the idea that there are no small surfaces to catch the initial fire. This is why I recommend the use of a section of visco to be used under the pile edge when testing BP, both for safety and for reliability. -dag
bob Posted November 10, 2012 Posted November 10, 2012 Touch paper can work pretty good to. The only problem I had with touch paper is some times (not often) the paper would just burn around the pile of powder .bob.
dynomike1 Posted November 11, 2012 Posted November 11, 2012 I got you so i need to run it through a 40mesh screen then dry it.THANKS
Algenco Posted November 11, 2012 Posted November 11, 2012 I got you so i need to run it through a 40mesh screen then dry it.THANKS Are you aware of the cost of "Ordering BP?"It's classified as 1.1, your going to pay a big hazmat fee, that's why Sporting Goods store don't stock it
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