confession time

[Merlin]

My bp with red gum /alcohol was great when first made. A few months later it lost most of its power-not just one batch even stored in a air conditioned environment in a zip lock with dessicant. Very frustrating. I then switched to benzolift using the same meal-d with great results even after months of storage with 0.3 ounces being good for 400 feet with a baseball. Once again I made BP this time 75/15/10 with one percent dextrin and hot distilled water. All chems were skylighter except I used willow charcoal. All chems ball milled in 12lb lortone for 24 hours. All chems precisely weighed and dried in drying box 48 hours. 1oz sent a baseball 200 feet. I surrender to hot benzolift. Good BP seems impossible after taking so much care and effort.

[FlaMtnBkr]

Where did the willow come from? What is your media made of and size? What diameter is a 12# jar? And probably most importantly, how are you processing the BP when it comes out of the mill?

 

Is the jar rubber lined? If not, does the BP start to clump and stick to the jar?

[Merlin]

The willow is lump from custom charcoals which I reduce to near airfloat. Media is lead balls some are actually 50 cal. muzzleloader balls and some are old 158 grain 38 cast bullets for which I have no use.(Don't load small bore anymore) Diameter of jar is almost 8 inches and has a octogonal shape inside for better mixing. It is rubber. Yes, after 24 hours the BP is starting to clump inside the jar.

My most recent attempt was to add one percent dextrin to the milling process. I simply removed the meal and added hot distilled water until it was workable then granulated through a 6 mesh sieve. Then I placed granulation on a 100 mesh screen in a drying box for 48 hours. The box has a small ceramic heater ducted to it and reaches 120-125 degrees and is vented at top. It is actually a large igloo cooler. I removed the powder which surely must have been dry and tried the baseball test. Poof.

 

I know the 158 38cal cast bullets have a small amount of tin and antimony but didnt think enough would be incorporated into the powder to change it. I know when I initially made the red gum/alcohol version it was quite hot- until about 3 months later.

Dextrin/water seems to be what the majority use so I gave it a try.

[dagabu]

More questions:

1. How full of lead balls is your drum?
2. How fast is the drum turning?

I would think any ball mill that takes more than a couple hours to mill BP is suspect, wrong media or speed or overloaded with comp.

[Sparx88]

Yah if it's overloaded it will take a looooong time and still not be that fine. I find that having it a little under loaded works best for me so you can hear the media making good contact with each other on the tumble.

[dagabu]

Ideally, the jar/drum should be 1/2 full of the media to get an effective falling heap.

[Merlin]

The jar is 1/3 full of lead. I put 20 oz-- 15oz nitrate, 3 oz willow, and 2 oz of sulfur. of powder in to mill. Anymore lead and the weight is to heavy for the motor. This is a 12 pound drum from Lortone.

 

The drum turns at 1 revolution in 2.5 seconds. It is a large rock tumbler. The motor has only one speed.

Edited November 25, 2014 by Merlin

[MrB]

Anymore lead and the weight is to heavy for the motor. This is a 12 pound drum from Lortone.

Those work pretty good for ball milling, but you really need to get the load right. Half filled with lead, quarter filled with what ever your milling.

When you put it all on the rollers, turn/spin the drum backwards a bit, and you should get it to start going as supposed when you plug the unit in.

B!

[Merlin]

The drum will hold almost 2 gallons of water. I have 10lbs of lead in it and 1.25 lbs of BP. The mill is rated for 12 lbs of material. The drum is about 1/3 full of media with the powder disappearing into it. If it were 1/2 full it would weight around 25 lbs or more.

Are you saying the drum must be half full of media or the BP ingredients proportioned to the amount of material. Half filled with lead, quarter filled with what ever your milling. That would be a 3:1 ratio of milling media to powder by weight. I am using a 10:1 ratio of media to material by weight. Are you saying it must be by volume? If so, I could not use lead. I got some ceramic for my 6 lb rock tumbler but afterward I wondered- so contacted the mfg and they said it could have a spark potential. I remember my old rock tumbler will only turn 1- 3lb drum with lead rather than two because of the weight. Ball mill explosions may be rare but when I got back on APC after a absence I see one of our members had a mill explosion. Cant take a chance with that you know.

The 12 lb tumbler was fairly expensive so I need to find a way to use it. But if it is media to material by volume. I can try as you say adding more lead. Motor capacity aside, there is a problem with the contact surfaces between the drive roller and the drum- both are smooth so when overloaded the roller turns but not the drum. I guess some kind of adhesive maybe.

Edited November 26, 2014 by Merlin

[Mumbles]

The poundage rating on a rock tumbler is really more of a rock related capacity. It has nothing to do with the actual strength of the mill or motor. It's pretty common to double the rating when filled with lead, and have it run without any issues what-so-ever.

[Merlin]

I stand corrected. It was painful but I sacrificed another 12 lbs of 45 cal bullets to the BP god. The jar is now half full and weights 28 lbs. To my total shock it does run---- actually better than the 1/4 full before. I suppose the next issue is the rotation. Funny I choose the name "Merlin" since I don't believe magic? The only thing I can think of would be to increase the diameter of the drive roller. That wont be easy as it is 3/4 inch diameter. Finding tubing with 3/4 inch ID and 1.5 inch OD is not likely. I knew I had everything precisely correct but it must be the magic of volume ratio and speed I overlooked. I fear how powerful benzolift made with good powder would be- not that I need anything that potent. The benzolift I have been using was made with inferior BP and it still very powerful. Anyway I really rather use BP if possible. If anyone has a suggestion on a way to increase the drive roller diameter I would appreciate. I am not good mechanically.

Anyway once again thanks to everyone for your suggestions.

 

 

 

The poundage rating on a rock tumbler is really more of a rock related capacity. It has nothing to do with the actual strength of the mill or motor. It's pretty common to double the rating when filled with lead, and have it run without any issues what-so-ever.

 

This is true.

Edited November 26, 2014 by Merlin

[Merlin]

Those work pretty good for ball milling, but you really need to get the load right. Half filled with lead, quarter filled with what ever your milling.

When you put it all on the rollers, turn/spin the drum backwards a bit, and you should get it to start going as supposed when you plug the unit in.

B!

You were correct. Thanks

 

[Bobosan]

Merlin,

 

You've got the lead in form of cast bullets but they are not as efficient a shape as round ball media. Might consider recasting your lead.

[calebkessinger]

Hello Merlin,

I too had a mill that wouldn't turn correctly. I turned a little bigger drive pully , tightened the belt up nicely. and slipped a heater hose over the drive roller. You could double hose your's but its not what you'd call easy. I used an air hose to put mine on. I'm not sure how other people do it. Denatured alcohol makes rubber slick also. or you can use straight dish soap..

[Mumbles]

To be honest, I'd try a batch of powder in your more optimally filled mill before worrying about try diameter of your drive roller. If you do the math, the optimal rpm is around 63 RPM. The hexagon and octagon mill jars tend to like a slower RPM, around 40 or so. Several others have mirrored this observation. I think it has something to do with the polygon jars almost being too efficient at lifting the media.

 

I bet you'll surprise yourself at how good the BP is after 3 or 4hr using the stock mill body.

 

The only thing I can't help with is the apparent decrease in quality over a few months using red gum bound BP. I have no explanation for that.

[schroedinger]

Merlin did you think about using shrink tubing for enlarging your roller? Edited November 27, 2014 by schroedinger

[Merlin]

It would take several layers but thats probably the easiest way to go. Good Idea

 

Merlin didy you think about using shrink tubing for enlarging your roller?

[Merlin]

Did everything by the book per advice on this comment -I thought. I have found I was using too much water to wet comp. Even though it could be granulated I couldn't get it dry completely. Put in ziplock in sun and moisture formed after 48 hrs in box and a week in open air. My drying box heat source is too small and doesn't put out enough heat and very little air. Two batches of dextrin bound BP set around for a week after the box and open air and still poof.

Rather than throwing it away I decided to experiment. I put it in a gallon jar and covered with acetone and let it soak a couple hours then dried- now BOOM! I also made another batch with 2% red gum and 50/50 denatured ethanol and acetone. It dried very quickly and I got 600 feet with the baseball using 0.9 oz of lift. Time will tell - I double ziplocked the BP with desiccant.

Problem #1 getting comp too wet.

Problem #2Very little air circulation and low temp (100 degrees) in drying box

Problem 3 was not enough media in ball mill.

[patsroom]

 

Sound to be a good time for my to preach.

 

O brother of little faith do not dip so deeply into the well of life giving water, but whether do so, so lightly as to wet thy Blackest of Powder and you shall be rewarded with thy labor.

 

.......................... ............Pat

[FlaMtnBkr]

Have you tried good old mother nature instead of a drying box?

 

I get my BP quite wet when granulating, so that it has the consistency of modeling clay. This is right before it gets too wet and a bit soupy. I granulate thru a screen onto trays in 1/4" layer and place into direct sun and sometimes add a fan. Once it starts to get hard I stir it once or twice and it it's dry in about 3 hours. Drying it this quick is important to the strength of the final product. It is much faster than BP that takes 12 or more hours to dry.

 

I use no binder yet I get durable grains hard enough to hurt fingers when trying to break apart. Don't know if dextrin could hold onto water a bit or slow drying? But I don't use it and have never felt the need to if it gets plenty wet when granulating. If it isn't wet enough to stick together it doesn't get hard grains.

[Merlin]

There are a few weeks in the summer when the humidity is low and the sun is shining at the same time. I dont know if dextrin aids in water retention but I know the KNO3 is hydroscopic. The rest of the time the humidity is quite high. I have heard of a lot of people using a drying box with a ceramic heater for drying quickly I just went too light on the heater. But if the weather was right the sun would be fine. Of course you are closer to the equator but it seems to me the humidity would be pretty bad in parts of Florida. I know back of the beaches at Mobile, Pensacola and Destin the humidity must be 105%. Unfortunately for me I haven't been much south of these areas except a trip to Orlando.

Edited December 2, 2014 by Merlin

[FlaMtnBkr]

Yeah humidity is ridiculous here all year except during the occasional cold snap. As long as the sun is shining it dries quickly.

 

KNO3 isn't all that hygroscopic actually. Charcoal can hold a bunch of water as it acts like a sponge. But once BP is dry it can last many years without absorbing much water. It's actually been found that 2 or 3 percent water in BP is a bit stronger than none. So a little isn't terrible for your BP.