Powder processing question...

[Victor3]

 I have around 8 lbs of black powder in the form of smooth round bars that are about 1.5" diameter by 6" long.

 These were produced decades ago by a friend of mine (now passed away), who used this powder in his rifles for many years. I've been using this same powder (broken down and sifted by him to about FG and FFG size), and it seems comparable to commercial BP as far as I can tell.

 My friend was well versed in the production of BP and had made a lot with the same formula over many years for the CW reenactment group he was associated with. Before he passed, he told me that the powder grains I now have is the same stuff as he always made.

 Unfortunately, I never inquired as to exactly how he went about processing these large chunks into useable powder.

 Any tips on how I might go about safely processing this BP into a useable form? I would like to use it in my cannons and mortars.

[Cat Whisperer]

Some things are obvious:

1. Nothing that would produce a spark.
2. SMALL quantities - just in case.

How hard/strong is the blackpowder?  I.e.: how much force would it take to grind them?  If it's a LOT I'd be inclined to use a fluid, such as water, to keep the ignition hazzard LOW.

[seacoastartillery]

      Try this:  Go to www.skylighter.com  Search the Projects Menu:  'Making high power black powder'      They tell you exactly how to break the pucks up safely in a process called "Granulation".

Regards,

M&T

[Will Bison]

The method suggested in Skylighter is the way I break my pucks. Just as they show, I use a hardwood stump and an Aluminum meat tenderizer and bust it up. I use canvas bags that I sew up myself.

The pucks that I make are 4 inches by 1/2 inch and weigh 1/2 pound. They are really hard after pressing at 4,000 psi.

[Victor3]

 Thanks guys. Sounds simple enough. I figured the process would be more involved than simply hammering the stuff to break it up. Almost doesn't sound safe, but I guess it is.

 With the price of BP these days, I thought it would be a shame to dispose of the stuff if I could make use of it.

 I still have quantities of the sulfer, saltpeter and charcoal that my friend used. All ball-milled and (apparently) ready to mix. I'm almost tempted to try my hand at making some BP myself after looking at the instructions on the skylighter website.

 CW - The "pucks" I have are very hard; almost like ceramic rods. They 'clink' when you hit one against another.

[cannonmn]

If I were doing the granulation the way you mentioned, I'd wear an industrial face shield, hat,  gloves, and would cover all my skin with thick cotton clothing (not synthetic since that can melt.)   What we fear probably won't happen, but the fact that it can happen would make me take precautions.

[KABAR2]

Something to think about is when commercial black powder is ground they add graphite into the mix to reduce friction. Friction is your enemy.

[and7barton]

I ball-mill the mixed ingredients, with lead balls, and added water, with a tiny amount of surfactant in the soup. Ball-mill for around 8 hours, then I dispense into a jar and cap it, letting it stand for around a week. Then partially dry until the mix is like a stiff porridge - Then into the hydraulic press in 150 gram batches. I wind it up to 2 tons and let it stand under pressure for 8 hours, then empty out, break up the cake with the fingers and allow to dry on an electric warming-plate for a couple of days, occasionally crumbling it up smaller. Eventually I push it through a coarse sieve (in small amounts, and well away from the main batch). Then it's a final dessicating period on the warming-plate and then into a plastic container.
It's pretty hot stuff.