laser200 Posted August 24, 2009 Posted August 24, 2009 Im a newbie and have been experimenting with black powder for about 3 months. I have finnaly made very nice granulated lift powder and can propel a 5oz. 3" shell about 400 ft or more with 14 grams of granulated lift. Very fast burning. But one day I tryed some without dextrin as my binder and it didnt do very well. Seems the dextrin adds a little power to it..Whats going on here?
TheEskimo Posted August 24, 2009 Posted August 24, 2009 Dextrin is added so as to make the granules of BP hard and strong. When you granulated without dextrin, the granules easily crumbled. So when you tried to shoot something, without the dextrin-granulated BP, the granules crumbled, and formed a big mass. The flame couldn't propagate between the BP, and so it burned slower. Having hard, sturdy granules allows space for the flame to move quickly in the BP.
Arthur Posted August 24, 2009 Posted August 24, 2009 The grain size of your BP is critical! With Nitrate sulphur and charcoal you will get good meal -very fine and well incorporated. However it will be a fine dust. This dust becomes BP when it has been granulated either with a binder or under great pressure.
laser200 Posted August 24, 2009 Author Posted August 24, 2009 Thanks guys....I have been ball milling this for 4 hours. Then i take my mill dust and screen some dextrin with it..I then wet it down with 75/25 alcohol/water. Then I kneed it and screen it with a 20 mesh screen. When i did this without dextrin i still got some nice grains bit like you said it would just crumble. But it still stayed together as long as I didnt crush it. But it burned slower. Seems like the dextrin does something besides provide a good glue/binder..I dunno...
Bonny Posted August 24, 2009 Posted August 24, 2009 Thanks guys....I have been ball milling this for 4 hours. Then i take my mill dust and screen some dextrin with it..I then wet it down with 75/25 alcohol/water. Then I kneed it and screen it with a 20 mesh screen. When i did this without dextrin i still got some nice grains bit like you said it would just crumble. But it still stayed together as long as I didnt crush it. But it burned slower. Seems like the dextrin does something besides provide a good glue/binder..I dunno... If you are using all the powder for the same (lift), add the dextrin before ball milling, it will be mixed much better than screening (and save a step)Also, you can leave out the alcohol as it is not needed. It will allow the water to incorporate a bit easier, and the powder will dry faster, but to save on $$. I add maybe 10% alc to my water if any at all.
andyboy Posted August 24, 2009 Posted August 24, 2009 I used to have alcohol in my water to break surface tension easier but now I just add a drop of YES dishwasher detergent.
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