39 replies to this topic

[jeffez]

Hi all, i'm new to this site.

I've been trying to make half decent black powder for quite some time now. I have a 6lb ball mill (2 x 3lb drums). No matter how much milling i do i never seem get anything better than slow burning meal type powder. I've had the mill running for upto 30 hours and the crap never improves. Another thing that annoys me is that the powder clumps up and sticks to the sides.

Can anyone help me? I have spent months trying to work out what i'm doing wrong.

[pyrotechnist]

Welcome to the forum btw, you need to be more specific about your black powder. What ratio are you using like is it the standard 75:15:10 ratio? also what charcoal are you using? the most popular seems to be Willow but others work to. I think the biggest problem may be with your charcoal. Make sure the charcoal you are using contains no ash and is cooked within an enclosed tin with only one air whole until the smoke stops venting. This will give you the correct type of charcoal that contains the volatiles needed for BP.

If the charcoal is not your issue then it may be your KNO3 that is to blame, where did you buy it from if I may ask?

[wjames]

some more information will help everyone in sorting your problem for you....

Perhaps :

Where does your Kno3 comes from...I.e garden centre, chem supplier, homemade....
What type of charcoal are you using, ie willow, pine etc, homemade or airflot etc
Where does your sulf. come from, lab grade or garden centre/pellets

What media are you Using, i.e shape and material.

Answers to these questions will help some people here answer your question.


Personally, i thought my BP was pants....and it was...untill i riced it.....And i simply added a binder, and pushed it through a garlic press ( crude, i know ) The difference was amazing - much faster.

Look forward to your reply, im sure someone will be more than able to point you in the right direction.

W James

[jeffez]

I bought all my chems including the charcoal from a chem supplier in aus - www.auschems.com
I'm using the standards 75:15:10 ratio. The charcoal is made from mallee. The media i'm using is lead (50 balls) in a 3lb drum.

[jeffez]

Personally, i thought my BP was pants....and it was...untill i riced it.....And i simply added a binder, and pushed it through a garlic press ( crude, i know ) The difference was amazing - much faster.

How exactly do i do this? Is there a thread or something somewhere you can direct me to? I've never heard of doing this. I've noticed that the high grad 4F stuff is made up of small granules, its this what your doing? Sorry for my ignorance, but i'm new to this stuff.

[wjames]

http://www.pyroguide...le=Black_Powder


A quick search on google shows that mallee charcoal can contain eucalyptus oil - which will make your bp stick to your ball mill barrel....and burn slowly.

[spanner]

Ideally, you want the jar to be 1/2 full of 1/2" media, and 1/4 full of comp to be milled. If you follow this you might only be able to mill with one jar at a time with out overloading it, if using lead media.

The RPM's of the jars will likely be slower than desired, causing erosion of lead media and a loss of efficiency. A 4" jar can need to run upwards of 90 RPM's, but I've run them slower with decent results. You can up the speed by taping the drive roller to a larger diameter or adding a length of rubber hose over the roller.

If using BOTH jars at the same time, try using 2.5 lbs. of media and 100 to 200 grams of comp per jar. The BP will be about as good as it will get at about 12 hours milling time.

These tumblers can be hard on drive belts/o-rings, as well.

Edited by spanner, 15 November 2008 - 05:48 AM.

[Arthur Brown]

Lots you can do!
1/ get some willow charcoal and mill it to airfloat and try that - there are lots of charts that rate charcoals by speed according to the tree they came from. Some woods may be easier for you to obtain than others. Do NOT try bbq briquettes they are bound with cement and have too much ash content, lumpwood bbq charcoal can make a slow BP useful for rockets and lift.
2/ BP needs to be fine granules for fastest powder -dust is slower! Learn about pressing and corning or learn to rice the powder with a binder and a little moisture.

Also note well that all speeds of BP have their uses. Slower BP is useful for rockets and lift, fast BP is for break charges, small shells need faster powder to break well, too fast a lift and the shell is damaged before it rises and it may malfunction.

Added;
With any mill add media to the drum til you have about 80% of the load weight of media then add enough ingredient to half cover the balls! This way the mill and belts last a reasonable time and you get sensible milling times.

Edited by Arthur Brown, 15 November 2008 - 11:38 AM.

[jeffez]

Ideally, you want the jar to be 1/2 full of 1/2" media, and 1/4 full of comp to be milled. If you follow this you might only be able to mill with one jar at a time with out overloading it, if using lead media.

The RPM's of the jars will likely be slower than desired, causing erosion of lead media and a loss of efficiency. A 4" jar can need to run upwards of 90 RPM's, but I've run them slower with decent results. You can up the speed by taping the drive roller to a larger diameter or adding a length of rubber hose over the roller.

If using BOTH jars at the same time, try using 2.5 lbs. of media and 100 to 200 grams of comp per jar. The BP will be about as good as it will get at about 12 hours milling time.

These tumblers can be hard on drive belts/o-rings, as well.

I'm using 2 small 3lb jars 4.5" in diameter. Each has 50 lead balls. They barely fill 1/8 of the drum, but that's what came with the mill so i assumed that was the best amount for that size drum. For all i know i could add more, but i don't know if that will cause over loading. There must be an optimal amount of media and comp i can put in these drums and get the best results.

So 2.5 lbs should be the right amount of media for me to use per jar? I'm not sure what 50 lead balls weigh, but if its under 2.5lb i can always get more.

[cooperman435]

Optional and correct way of loading a drum is to have exactly 1/2 the drum full of media (whatever the size we wont go into that now) then load the material to be milled till it is level to the media. Ie fills all the gaps between the balls and just covers them.

[Arthur Brown]

A good ballmill will work well to Cooperman's instructions, an economy rock tumbler will not last long if you load it half full of lead balls! If it turns, it will kill the belts and possibly the motor quickly if overloaded.

Weigh out the balls and try to run close to the rated load. The machine may work if over loaded but may offer shorter belt or machine life. Possibly put all the balls in one drum to get a half full mill jar without overloading the machine.

The big problem with Chinese mills is the lack of spares. If you blow the motor you are on your own.

[spanner]

There must be an optimal amount of media and comp i can put in these drums and get the best results.

OK, you have a tumbler rated for 6 pounds, right? So, using ONE jar, optimize the media (1/2 of jar capacity- you will need approx. 200 TL. This will be about 5.4 lbs. if using pure lead) and material charge (1/4 of jar capacity, or as Cooperman435 said, cover the media- in this instance, both work out to approx. the same thing). Use lead media no larger than 1/2" OD.

This one jar (remember, the tumbler doesn't care if there's one or two jars, discounting roller flex) can be optimized with out exceeding the 6 lb. capacity.

So 2.5 lbs should be the right amount of media for me to use per jar? I'm not sure what 50 lead balls weigh, but if its under 2.5lb i can always get more.

The 2-1/2 lb. referred to earlier, was if you were going to try and use BOTH jars- and would not be an "optimized" charge.

I would suggest you try using just one jar, optimized, and think about turning the jar faster.

Edited by spanner, 15 November 2008 - 04:17 PM.

[jeffez]

Optional and correct way of loading a drum is to have exactly 1/2 the drum full of media (whatever the size we wont go into that now) then load the material to be milled till it is level to the media. Ie fills all the gaps between the balls and just covers them.

Good to know. So i guess in theory this is what to aim for, but i my case it may be something like 1/4 of media and material, to stay within the rated load.

Weigh out the balls and try to run close to the rated load. The machine may work if over loaded but may offer shorter belt or machine life. Possibly put all the balls in one drum to get a half full mill jar without overloading the machine.

OK, you have a tumbler rated for 6 pounds, right? So, using ONE jar, optimize the media (1/2 of jar capacity- you will need approx. 200 TL. This will be about 5.4 lbs. if using pure lead) and material charge (1/4 of jar capacity, or as Cooperman435 said, cover the media- in this instance, both work out to approx. the same thing). Use lead media no larger than 1/2" OD.

Ah ok now this is making more sense.
So assuming i cant go anywhere near the 1/2 full of media amount using both jars and staying withing the 6lb load. I should use just one jar, so i can get closer to the ideal 1/2 media+comp amount. Thus i would be grinding the same amount of comp but only using 1 jar?

Can having very little material yield even faster/better results?

Edited by jeffez, 16 November 2008 - 01:21 AM.

[jeffez]

http://www.pyroguide...le=Black_Powder


A quick search on google shows that mallee charcoal can contain eucalyptus oil - which will make your bp stick to your ball mill barrel....and burn slowly.

So we can safely say the mallee isn't good for for making fast burning bp then. I'll see about getting some willow then. Does anyone know where i might be able to find some?

[wjames]

I would say so.

Is willow native to your country ????

There's a chart somewhere that shows loads of types of charcoal, and what uses they have.

I'm sure someone will point you in the direction of it.