33 replies to this topic

[bobconan]

I filled up my mill a little more then 1/4 with damp meal and put some lead weights in and 30 hours later i got a 2 inch solid ball of bp. It cracked when i hit it with my mallet. had like a hard crust. Really weird. Any ideas as to what i didnt do right?

[Richard H]

how much media did you charge the jar with?

[maxman]

Sounds like it was too damp! Dont you mill it dry? I do and it works great every time.

[pritch]

I would be interested to know what Richard is getting at about the amount of media to balls ratio. I allmost always get like little rabit poos of meal. They form little solid clumps in other words.

[Stuart]

If it forms a solid block there is too much water there. If I put to much in, my media go from being quarter inch thick to half inch thick. The Black Powder on them goes rock hard too. By the sounds of things, you don't put much in your mill so thats probably why you get a solid ball where as I don't

Stuart

Edited by Stuart, 11 June 2004 - 01:23 PM.

[Richard H]

I always mill the charge dry, with 1/2 a jar of 1/2" diameter brass round bar media. Never had any problems and always excellent results with this setup.

[pritch]

I probally fill about 1 8th of the jar with balls and 50 grams of ingredients is about half of that level. I always mill dry and only once have I got a nice flowing powder as the end result. I seem to always get rock hard clumps that I have to grate through a 40 mesh. I might try a technique I read on here a little while ago, where you blow the milling equipment with hot air before you start. He claimed this reduced clumping.

[Chaz]

I've had this problem, it was the first time I had ever made ball milled BP. All clumped together in a ping-pong ball sized sphere. Took quite a bit of force to get it to break.

Just add less water next time, two or three drops is all I add.

[dfk]

This is another one of those things that has been discussed many times in the past.

Why are you guys milling damp, is it for safety?


As I said this has been discussed a lot and I think a LOT of people here and else where mill dry with good results, you just have to respect the process.
...Really...what's 3 drops going to do that none Isn't?
Milling dry will sure stop your clumping problem. If you realy want it wet try milling in slurry. The only thing about this is that you have to re-mill DRY after the slurry dries to make sure any re-crystalized KNO3 is well incorporated.
On the other hand your clumping 'problem' can be used to your advantage. First mill the mix dry to get a good meal, then dampen the mix to purposely "ball up" the powder. This can then be granulated for BP which works at the least better than pulverone.

Just my two and a half cents

Marcus

Edited by dfk, 12 June 2004 - 08:13 AM.

[Stuart]

Milling wet does give better results though. When I say wet, I don't mean wet wet, I mean a few sprays of water per 100g. This does make a massive difference. I would never mill a slurry, sooooo much effort for so little. Just spray it with water a few times and your fine. If it still clumps, spray with less.

[dfk]

Soooo much effort for so little what?
Since this post was geared toward those who were having problems with clumped up Meal or those worried about milling dry, I guess I wasn't talking to you, Stuart.

This is more work but gives a quicker powder than any dry one I've ever made.
I only did this when starting out and was under the impression you HAD to mill wet, yet wasn't able to get more than a meal coated mill with lead balls bouncing around.
So don't worry Stuart, whether drying a slurried powder is too much work for you or not is irrelevant. Don't read more into suggestions than is their; no one was telling you to do anything.

Marcus

[bobconan]

When i smashed Up the ball it made great grain powder. What size sorting meshes should I have?

[Phoenix]

I had a similar problem to this, with my BP packing into the bottom end of the mill jar if I added more than 1.5% water. Rhodri suggested that it might be due to dextrin-like substances contained in the charcoal, which were especially likely to be present in willow, so I tried with plain old barbeque charcoal, which solved the problem. I can mill with 3 or 4% water now without packing, which is enough to make the BP look and feel slightly damp. I would guess that this would reduce its tendancy to take fire from a spark, if a stone or something somehow managed to find its way into my mill (eg from the charcoal) and reduce the chances of static charges in the jar. Furthermore, it also makes the BP burn slower, so may help reduce the force of the explosion if the jar did pop.

BP that has been dampened does usually burn noticably faster than BP that has not, as the KNO3 can dissolve and become better incorporated with the other ingredients (especially the charcoal). If you want to reap the benefits of this, but have problems with clumping, you can mill the charcoal and sulpur together for a little while, with half of the KNO3 (37.5%) then dissolve the other half in hot water and incorporate it into the other ingredients. Let this dry, then stick it back in the mill, to grind up the larger KNO3 crystals that will from on drying.

Of course, even if you mill it dry, you will probably wet it before pressing, so you will also benefit in this way. I have not noticed any problems from the KNO3 crystalising when wet with 10% water, and it helps to make harder grains. I have never found any benefit in wetting with pure alcohol.

[Stuart]

Soooo much effort for so little what?
Since this post was geared toward those who were having problems with clumped up Meal or those worried about milling dry, I guess I wasn't talking to you, Stuart.

This is more work but gives a quicker powder than any dry one I've ever made.
I only did this when starting out and was under the impression you HAD to mill wet, yet wasn't able to get more than a meal coated mill with lead balls bouncing around.
So don't worry Stuart, whether drying a slurried powder is too much work for you or not is irrelevant. Don't read more into suggestions than is their; no one was telling you to do anything.

Marcus

I didn't see you as directing the comment at me, I was just offering my opinion and advice on the matter. When I say so much effort for so little, I mean Blackpowder. Making your ball mill really messy and having to clean it and dry your Blackpowder for just 50g, that seem's like a lot of effort to me. Just my opinion.

Edited by Stuart, 12 June 2004 - 07:04 PM.

[dfk]

I never made "just 50g", and as for cleaning the mill, it seemed to do that itself after recharging and milling the dried powder.

I would guess that this would reduce its tendancy to take fire from a spark, if a stone or something somehow managed to find its way into my mill (eg from the charcoal) and reduce the chances of static charges in the jar. Furthermore, it also makes the BP burn slower, so may help reduce the force of the explosion if the jar did pop.

Makes sense.

If you want to reap the benefits of this, but have problems with clumping, you can mill the charcoal and sulpur together for a little while, with half of the KNO3 (37.5%) then dissolve the other half in hot water and incorporate it into the other ingredients. Let this dry, then stick it back in the mill, to grind up the larger KNO3 crystals that will from on drying.

This would be necessary to, as you say "reap the benrfits" of crystallizing the KNO3 into the charcoal as opposed to just spraying the water into the powder.
I think it takes somewhere between 8 and 15% water to get the KNO3 to actually dissolve, outside of this you just have damp powder

Edited by dfk, 13 June 2004 - 05:46 PM.