Comments on: Fireworks Chemical Milling – Fast

By: nextradrealtyme

nextradrealtyme — Mon, 24 May 2010 13:09:49 +0000

be careful with what you mill using silver/ copper although most money is now nickle/bronze,
a lot of pyro comps may react to either of the copper/bronze or the nickle/silver
plus using money that way is illegal (haha defacement of gvt property)
so i would really look for published papers on the reactivity of the metals in your media,
inert media is the best! ie LEAD/antimony/bismuth, in some rare instances steel for inert fuels, or ceramic

but i may be wrong….this is just how i do things… as i was taught

By: Shaggyman

Shaggyman — Sat, 22 May 2010 16:53:13 +0000

I have been using quarters for milling media. They seem to do a great job cascading around, and since they are cash, in the end they don’t cost anything at all.
Does anyone see a potential for trouble with the silver and copper in some comps?

By: nextradrealtyme

nextradrealtyme — Sat, 22 May 2010 12:42:26 +0000

seems to me that the lead balls they are using are too soft
casting some antimony / bismuth in it will harden it and lessen any lead dust in your mix

By: nextradrealtyme

nextradrealtyme — Sat, 22 May 2010 12:37:46 +0000

seems to me that if your kno3 is bricked then maybe using a burr mill type of grinder would work just to bring it down to manageable size..
anyone try that?

By: nextradrealtyme

nextradrealtyme — Sat, 22 May 2010 12:34:59 +0000

love the .50 call ball but…..
but i found some GREAT .78cal grapeshot for milling! (grapeshot is the size of a quarter)
most blackpowder gun stores may have these behemoths on clearance
used for hunting buffalo i bought 100 of these for around 15 dollars.
these are great for cannons and for milling almost anything

By: Jay Schaeffer

Jay Schaeffer — Thu, 11 Mar 2010 04:18:14 +0000

I’ve had several of these mills over the years. I have never milled chemicals in them but just about everything else. I found with everyone I had that, over time, a large amount of milled material builds up inside the motor housing. It gets past the seal on the blade spindle. I have already shaken several tablespoons of milled material out of the motor housing. These mills have brush motors which always have some arcing. I’d be careful milling chemicals. I think an unplanned ignition is possible. I know someone who actually did have a fire problem using a blender. Not from the powdered chemical getting into the motor and igniting but from the friction where the spindle goes through the bottom. I just wanted to share this so anyone who uses this method can be aware of a possible safety issue.

By: Kenkzak

Kenkzak — Fri, 09 Oct 2009 19:49:24 +0000

Last year I received a 5lb brick of KNO3. Never had this problem before and my screens and mortar & pestle quickly proved unequal to the task, so I went shopping.
I found a relatively tiny food proccessor [yet bigger than a coffee mill] on closeout sale for $6. It got me through the job at hand but I rank it as a poor performer. It would reduce the load to about 1/3 powder, and 1/3 screenable with some effort. The remaining 1/3 went back in with the next load.
I have a Black & Decker coffee mill, but my coffee is more important than my Salt Peter.. After reading this blogpost, another coffee mill is now on the horizon.

Some folks I know use lead balls in thier tumblers and they mention that the oxidizers comes out looking a bit grey. I worry about the lead contamination in the smoke being breathed in????

By: HEGilliam

HEGilliam — Thu, 08 Oct 2009 02:03:55 +0000

Tom,

First, for you and for everyone else reading your post… I have a very strong bias against ceramics for *mixed* pyro compositions.

I am aware that there are probably “safe” ceramics and unsafe ones. I have alumina media from Coors, and their piezo electric activity in the 5 gallon mill bucket in my cement mixer looked like a blue firestorm! I have absolutely no doubt that those media would cause a batch of black powder to explode so fast it would make your head spin.

I am aware that some ceramics do not produce piezo-electric sparks. But how do one really know, until one uses them? “They all LOOK the same–white, heavy things…hmmm, did they send me right ones?” I personally ain’t willing to be the guinea pig.

Ceramics are fantastic for any *individual* chemical I have ever milled, from caked oxidizers to even titanium turnings. Great results.

But if you are milling black powder or any other mixed comp, I would only recommend non-sparking lead or brass (there are other alternatives, but these are the easiest to get hold of).

(I am sure this will provoke naysayers — I’ve been in this argument before. The argument goes like this: “well I have been using ceramics for 5 years and never had an explosion.”

Which is kinda like “I have been driving for five years without wearing a seatbelt, and haven’t been killed, yet.” )

All of these milling media are heavy. Their weight will make quick work of most rock tumbler motors (the cost of ball mills appears to be proportionate to their size and horsepowder–duh!)

I dunno about them triangles. I am a simple country boy. We only had round balls when I was a pup. And bothering to mix media begins to sound complicated to my lazy, simple nature. I am lazy, and I am impatient. I just wanna do the least work to get the job done right.

Here’s my formula for successful ball milling of excellent black powder.
- Open ye mill jarre
- Fill half of the jar with lead balls (.50 caliber are nice)
- Fill 1/4 with rough mixed BP chemicals–leave 1/4 empty
- Cap it, and turn the mill on.
- Go do whatever I damn well please for 2-4 hours, or 8 or 10 (but 2-4 will do it).
- Come back and retrieve finished black powder

Works perfectly every time. I dunno about them triangle thingys–I might worry about them starting to lose their shape or something. I got enough worries. Hell, it took me 5 years to get over my phobias of the millenium bug!

By: HEGilliam

HEGilliam — Thu, 08 Oct 2009 01:42:29 +0000

Ron,

The kindness of your words is exceeded only by your taste in writing! Thanks.
Go outside and LIGHT something!

By: Tom Fay

Tom Fay — Wed, 07 Oct 2009 03:41:32 +0000

Most of the tips on blade milling reaffirmed my own experience and observations. My own particular mill is a bottom-of-the-line, Mr Cofee item. I don’t fill it beyond about 1/4″ from the rim, and I’ve found I do as well by sort of rolling it around when I run it as I would by shaking it. I’ll also give ie an occasional tap or two on the edge of the bench between depressions of the button. These techniques keep the load on the bearings from spiking, increasing the life of the unit.

What I eventually want to do is not just get one for fuels & one for oxidizers, but one for Chlorates, one for Perchlorates, one for Nitrates, one for metallic fuels, and one for organics. The chances for cross contamination are just too great. All it takes is a few stray molecules getting with some other substance they don’t get along with, and you could at least burn the place down (perhaps spectacularly), or maybe wind up eating with your feet… by Braille.

On to ball milling, I have a couple of questions about that. Right now, all I’ve got is one of those little Chinese rock tumblers with the rubber drums. Ceramic media seemed to rough up the interior of the jars a bit, but I was making a small batch of meal and didn’t have a good way at hand to see what kind of contamination I was incurring. This was 1/2″, spherical, porcelain stuff from CoorsTek mixed 50/50 by count with 5/8″ round brass, the idea being that the heavier brass stuff would exert more force on the working sufaces of the ceramic media. It worked according to theory, the unintended consequence being the above-mentioned erosion of the drum, plus the fact that the much harder ceramic permanently scarred the Hell out of the brass; no more nice & shiny. So are there any sources on mixed grinding media for ball mills, such as compatibility, contamination or simple size charts? Something like that would be mighty handy.

My other question has to do with the use of vibratory media in ball mills. I was at Harbor Freight & saw some triangular, ceramic media about 3/4″ corner to corner, about 1/4″ thick. There were smaller and larger sizes, but all had the same basic proportions. Would using these buy me any particular advantage in performance or economy? (Not in this little machine, of course.)

Thanks, TF.