16 replies to this topic

[Sambo]

So you're using iron as milling media! Spark crazy, you might want to change those very soon and save an accident waiting to happen.

[FrankRizzo]

Moisture *may* be the cause of this problem, but you'd see the effect shortly after the milling process began if that was the case. What's more likely is that the powder was milled to the finest state it could get to after a few hrs, and the continued mechanical action for many hrs afterward caused the potassium nitrate and sulfur to melt and agglomerate the mix. A bit of heating is good, as it helps to obtain a more intimate mixture, but over 90F tends to cause clumping; either on the media or at the ends of the jar. These clumped mixtures are also usually the best performing though due to their intimacy of mixing.