Question about ball milling

[laser200]

Has anyone tried ball milling their powder with a tiny, tiny bit of water/moisture in the mill? It seems to make it mix and combine more making it a bit more stronger...Or is it just me? Im not talking about a lot. Just a bit to make it kinda like not dusty. Hard to explain...

[TrueBluePyro]

You can 'wet mill' black powder. When I first ball milled my black powder I was told by a scientist that wet milling would be the safest way to do it. I added a little too much water, but once I got it out I was able to just granulate straight out. Also it was pretty good quality black powder.

[dagabu]

You "can" mill it wet but it still has to dry and when it does, the KNO3 will recrystallize into much larger pieces and make it much less reactive. The best and fastest BP is milled a dry as you can get it. This also helps immensely with clumping while being milled.

[laser200]

Cool...Yeah it seemed to cut my milling time in half also. And yeah the safety of it being damp pays off too. Appreciate the reply...

[laser200]

You "can" mill it wet but it still has to dry and when it does, the KNO3 will recrystallize into much larger pieces and make it much less reactive. The best and fastest BP is milled a dry as you can get it. This also helps immensely with clumping while being milled.

 

I dont let it dry for my granulated. I just take it out and screen some dextrin in it and wet it down more. But I could see what your talking about. Thanks

[Mumbles]

Wet or damp milling was a fad a few years ago. As was wet pressing BP motors. They got the idea from commercial BP manufacture where it is milled damp. That is a completely different process though. I used to do it. Now-a-days, my nitrate and charcoal probably already have enough water in it.

[laser200]

LOL Mumbles.. Thats actually how I figured this out. I left my KNO3 open over night and it it got damp with the high humidity. It WAS in a plastic bag.

[Mumbles]

I've been drying my KNO3 lately. Approximately 0.8% weight was lost, but that little bit really makes a difference.

[Skycastlefish]

I've been drying my KNO3 lately. Approximately 0.8% weight was lost, but that little bit really makes a difference.

How do you dry your KNO3? I haven't had any problems with wet chems but it does gets pretty humid down here. Too humid to just stick it outside and wait.

Edited July 9, 2010 by Skycastlefish

[Mumbles]

Oven at 350 for about 2 hours. They're prilled so I grind them to -40 mesh first. They dry faster and better that way.

[Skycastlefish]

Oven at 350 for about 2 hours. They're prilled so I grind them to -40 mesh first. They dry faster and better that way.

Alright, good to know. How long do you wait until you mix it with other chems? I presume every minute passed it would absorb moisture again?h

[Mumbles]

Oh, I just dry a few kilos at a time, and store it in a sealed container. There is a little caking, but there has been a few weeks of working time thus far.

[50AE]

If you damp it, it will clump on the walls of the drum.

If you wet it like blackmatch slurry, KNO3 will recrystallize, useless.

 

So better mill your black powder dry.

[dbryceman]

I just milled a batch of BP a couple of weeks ago, for the first time, and the result looked great, but the granulated powder would literally lift the dummy shell out of the mortar and plop it on the ground. I made it to 20 feet or so and that was sad. So, I thought that maybe a longer milling time would be the solution. I milled a batch yestedray for 12 hours, and it appears to have been a huge mistake. I now have 2 golf-ball sized rocks of very fine black powder, and I don't know if that's good or bad, but right now, it looks bad. I can only assume that this is due to humidity, but my chemicals appeared to be pretty dry when I combined them. They are stored in plastic bags, and sealed in plastic containers.

 

That said, it seems to me that adding any moisture at all to BP while milling would be a bad idea. I now have to figure out how to turn these two boulders back into powder, and any advice would be appreciated. Like I said, they seem to be composed of well-milled powder (12 hrs), the size of golf balls, and on top of that, they are so hard that they make a metal spoon ring when tapped. I am not sure at which point during milling the caking and resulting boulders started forming. It occurred to me that it might be exciting just to light one up, but I don't think I need that sort of excitement.

 

Does anyone have a good idea on how I might safely 'undo' these BP boulders and get to making granules for lift? Did I mill the powder too long?

[Algenco]

Milling until the BP clumps or sticks to the jar is a good thing.

You had a lttle moisture, probably in the kn03.

Grate the "balls" through a screen, dampen and rice

 

Or put them in a bucket and crush with the end of a baseball bat as if you would in corning

[dbryceman]

Milling until the BP clumps or sticks to the jar is a good thing.

You had a lttle moisture, probably in the kn03.

Grate the "balls" through a screen, dampen and rice

 

Or put them in a bucket and crush with the end of a baseball bat as if you would in corning

 

 

Thanks for the quick response! I thought the BP balls were too hard for a screen, but in time, a 100 mesh screen turned them back into dust.

Off to granulating...

 

Thank you again.

[Col]

Thanks for the quick response! I thought the BP balls were too hard for a screen, but in time, a 100 mesh screen turned them back into dust.

Off to granulating...

 

Thank you again.

 

Hi

I built a new mill recently and have the same problem with compaction after running for just an hour. I can`t make up my mind if its moisture in the kno3 or simply that the particle size is as small as its going to get.

I put some of the compacted bp through a 120 mesh screen, milled it for another 3 hours in the smaller mill and its slower than the one hour stuff.

I`m not sure what to think now

Edited September 15, 2010 by Col

[50AE]

Actually, I'm profiting of the clumping in the drum as indicator when BP is ready.

I first mill the KNO3 and S together. The mix gets fine to a point where it starts to clump and the milling sound changes, because media pieces are hit one another without material to be milled.

I take out the yellow mix, screen it, add it to the drum again and put the previously milled airfloat charcoal. Then I homogenize the mix together for 5-10 min and I get the BP I need.

[dagabu]

Clumping in the summer is very common. Various groups have discussed this ad nauseum and it has overwhelmingly been decided that the combination of heat and humidity are to blame. It could be the charcoal or the KNO3 holding the moisture, you would have to make sure that both ore completely dry before ball milling to get it to not clump.

 

The recommendation is to check the ball mill every 30 minutes and/or tap the jar to break up the clumps.

 

Personally, I don't mill BP in the summer and wait until its winter to mill BP. It can rum for days with no clumping when its cold and dry. The MAJOR draw back is that static is easily built up in the winter and a jar can ignite due to a static spark.

[Fly]

Sorry but I really question static ever starting black powder to burn.A static spark has not enough

heat to set it off.http://www.ctmuzzleloaders.com/ctml_experiments/sparks/sparks.html

 

Fly

[dagabu]

Sorry but I really question static ever starting black powder to burn.A static spark has not enough

heat to set it off.http://www.ctmuzzleloaders.com/ctml_experiments/sparks/sparks.html

 

Fly

 

I cant access the link so I cant argue the point you have brought up but I can say that PVC is a great carrier of static and rolling it on rubber coated driving shafts is a good way to build a charge on the PVC.

 

Pressed and corned BP is a completely different animal then a volatile dust inside a jar. I think that a test using the same conditions that are present inside a jar would be a better apple to apple way of testing the validity of my/your claim.

[Fly]

 

dagabu

This has been in debate many, many times before.We are not talking flash but BP as you already know.

I have seen stun guns used also to try & set bp off & never did.Static just does not have the amps

to generate enough heat.

 

Many of the explosions in black powder factories have been thought from static being the cause.Others

think open electric motor was the cause.Who really knows.

 

But I think static get a lot of undo blame.

 

Jmohop Fly:wacko:

[dagabu]

Fly,

 

There is only one way to find out.

 

Lets experiment. What sparking threshold would you agree to? Piezoelectric spark? Stun gun? Lets do this!

 

I understand your argument about BP, I cannot say that I completely disagree with a test on solids but the environment inside the ball mill jar are very different then lighting pressed and corned BP.

[Col]

Thanks for the info guys.

I`ll think i`ll try Mumble`s idea of drying some kno3 in the oven and see how much it weighs afterwards although it seems pretty dry. I have 26lbs of lead in the jars so i don`t relish the idea of emptying them to break up the bp

Edited September 15, 2010 by Col

[dagabu]

Thanks for the info guys.

I`ll think i`ll try Mumble`s idea of drying some kno3 in the oven and see how much it weighs afterwards although it seems pretty dry. I have 26lbs of lead in the jars so i don`t relish the idea of emptying them to break up the bp

 

No need to open it, just tap the ends and sides with a hammer handle to dislodge them. The tumbling action will crush them again.