I have a bit of experience in milling chemicals with coffee grinders. I have
used both the blade type (cheap) and the burr type (more expensive). I have
also had a little experience using a rock tumbler as a ball mill. My rock
tumbler is the little cheap one you can get from Harbor Freight ($29). I
used marbles in the rock tumbler as media.
There is no comparison. The cheap ball mill IS VASTLY BETTER but slower. The
little tumbler could be improved with media that is more dense than glass
(302 stainless, brass, lead) but the little motor has difficulty with the
load and the tub does not rotate quickly enough. The little ball mill with
marbles will take a long time but will result in true air float charcoal
The coffee mills will quickly grind down small amounts of chemicals but will
result in a variety of sizes of ground chemical when you are done. There is
no real uniformity and true air float charcoal will not happen. Also I have
burned out a couple of the blade types grinding a couple pounds of KNO3.
The result of my experiences is that I am building a more serious ball mill
in the Sponenburgh style. To me that seems the only way to go. With a little
shopping and scrounging you should be able to make the mill for less,
perhaps much less, than $60 US. The jar is another matter. I chose to buy a
Lortone 6 lb. jar for $38. It is well sealed, easy to clean. and will result
in little shrapnel in case of a disaster (it has a rubber tub). Other tub
designs using PVC are all over the net.
You can search the news groups for media advice. I bought 302 stainless and
brass balls as media. But you can make excellent media from lead tire
weights and a .50 Cal or greater muzzle loader lead ball mold. I tried the
Sponenburgh aluminum foil method of casting lead media and found it a pain
in the you-know-what and the resultant media was all over the place in size.
As we speak I am trying to make some lead ball molds from plaster of Paris.
Check out the news group for instructions on how to do this. It is a first
for me so I do not know how well it will work.
Post by RoCkaZ
I always used to pulverize chemicals (KNO3, Charcoal, Sulfur, etc.)
with a coffee grinder, however when i started reading more info about
making fireworks, I noticed that it is always suggested to pulverise
with a ball mill, and not a single word about coffee grinder. Why is
it so? Wich of these machines makes a better result? I'm not talking
about how long it takes, or how messy it is and so on, but the size of
the powder particles. I'm going to make some BP and other
compositions, and now I'm a little confused whether to make a ball
mill, or to get a coffee grinder. I'd like some pro et contra's for
both machines from people who have dealed with both of them, and have
something to say ;) Thanx in advance!