lacrima97 Posted June 12, 2006 Posted June 12, 2006 I have noticed recently that when I mill black powder for long periods of time, it will become increasingly a lighter grey color and with a powdered sugar consistency. Does anyone else seem to have very grey bp? It didn't do this when I used to mill it for short times.
Mephistos Minion Posted June 12, 2006 Posted June 12, 2006 Depending on the charcoal I use it is greyer or blacker. When I use commercial hardwood charcoal that I get in big sacks it is very light grey, but when willow or pine is used it is alot darker. I have never had really black black powder though.
lacrima97 Posted June 12, 2006 Author Posted June 12, 2006 Ah, so It has more to do with the charcoal used. I have also used hardwood lump charcoal in this batch.
Mumbles Posted June 12, 2006 Posted June 12, 2006 Yes, of course it does. What else is in there you think would cause it to turn darker? Mine usually comes out a bit darker than that. It doesn't turn black for me until I wet it.
Canadian_Pyro Posted June 12, 2006 Posted June 12, 2006 Depending upon the alloy used, lead media contamination could cause a lighter colour. I doubt it has anything to do with the charcoal if it is getting progressively lighter throughout the milling period. Remember, the smaller a particle gets, the less light it will reflect.
lacrima97 Posted June 12, 2006 Author Posted June 12, 2006 As far as the lead media goes, I actually used pennies this time.
Canadian_Pyro Posted June 12, 2006 Posted June 12, 2006 Ah, thats interesting then, I have never seen BP that light in colour. Did the copper plating chip off of the pennies and contaminate your powder with zinc? You would have noticed that though.
lacrima97 Posted June 12, 2006 Author Posted June 12, 2006 The pennies actually turned very very black. I tried to wash them and then remained black still. I then ran some aluminum shavings and the pennies in the ballmill for about 10 minutes (to try and remove the carbon color), and I didn't see any zinc exposed whatsoever. The bp burns pretty fast though. Its good stuff.
justanotherpyro Posted June 12, 2006 Posted June 12, 2006 My meal powder is always gray and burns very fast. It will clump up into one big ball also if I do a 300-400g batch. True Black Powder is after the wetting process which makes it darker in color and faster. Newspaper Carbon gives a substantially darker colored meal, although it is still gray.
lacrima97 Posted June 13, 2006 Author Posted June 13, 2006 Here is the exact same bp from the pic above. I did a very fine granulation of it to see if the color would change.
Swany Posted June 18, 2006 Posted June 18, 2006 The blackness of the pennies could be expected as most likely the coating was oxidised black CuO. My meal is light, and granulated is similar to your color.
Mumbles Posted June 18, 2006 Posted June 18, 2006 More than likely it is copper sulfide, not copper oxide. Sulfur corrodes copper on contact. This is one of the things I don't like about brass media, but I won't go on that tangent. Sulfur is much more likely to corrode the copper than the KNO3 would be to give up oxygen to it.
Douchermann Posted June 23, 2006 Posted June 23, 2006 Blackpowder will be grey regardless because of the white from the potassium nitrate. Its like when you mix white paint with black paint. The reason short milled blackpowder is darker than powder milled for a long time is because in the short milled powder, the potassium nitrate is a lot bigger of a particle, thus doesn't mix as well. A good demonstration would be mixing powdered sugar and charcoal vs granulated sugar and charcoal
Dr Boom Posted June 24, 2006 Posted June 24, 2006 Also, does anyone consider that a compacted BP grain will be darker after it is pressed? I've converted an old dryer to turn my powder and I have a mister with a 2 liter bottle attached to it so I have a constantly but not overly wetted batch. Mine almost has a "potting soil" color to it after it's done mixing. And the color seems to improve on compression with my 5T press- I'll try to get some pics up here.
joe609 Posted June 24, 2006 Posted June 24, 2006 The reason short milled blackpowder is darker than powder milled for a long time is because in the short milled powder, the potassium nitrate is a lot bigger of a particle, thus doesn't mix as well. Wouldn't it be the other way round, shorter milled bp would be lighter in colour as the kno3 is not mixed in as much therefore the white colour would be more visable, in the longer milled powder, at least in my experience it is always darker as the kno3 is ground really fine and forced into the pores of the charcoal making the kno3 even less visable as it is concealed by the charcoal.
lacrima97 Posted June 24, 2006 Author Posted June 24, 2006 That pick of my meal powder up above was milled for about a day. In my experience, it definately gets lighter, the more you mill it. Thats how I usually judge if it is done or not.
Douchermann Posted June 24, 2006 Posted June 24, 2006 It might be lighter when initially mixed if its not mixed properly. It will get lighter. Before its milled there is less surface area of the potassium nitrate to be exposed. After its milled more surface area of the potassium nitrate is exposed, thus a better blend of the components.
ADP9 Posted June 30, 2006 Posted June 30, 2006 My BP is very dark even after KNO3 and Cab-O-Sil, The charcoal is definatley the reason in mine though. I made it myself from a certain vine that is abundant in my area. I found that it comparatively burns faster than willow based BP. Its great stuff, especially if milled for long times.
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