How many hours do you ballmill your BP?

[MadMat]

You guys surely gave me something to rethink using glass for milling. I guess I've just gotten lucky so far and don't wish to push my luck!

[MadMat]

One other thing I forgot to mention as far as static electricity is concerned. Anyone considering building a belt driven ball mill should have some form of grounding on the jar (look at how a Van De Graff generator is constructed). This also includes PVC. You can build up a hell of a static charge with PVC. If you dont believe me, take a piece of PVC pipe and rub it with simply paper towel. If the air is dry and the pipe clean it will charge up very well.

[TYRONEEZEKIEL]

Van der graff generators work because it isnt grounded. I used a direct driven pvc mill for 7 years or so. No problem at all. That is another advantage about milling outside. It is just too humid where I live outside for static to be built up. Even in the winter time I have never had any kind of indicator of static on my PVC jar. If I were to be milling in conditioned air I would be more concerned.

[greyhawk]

Try with 4%

And go down to 2%, if you dissolve it in the water you use to bind it.

Dexrin!!!

I started milling powder about a month ago - made a couple kilos and couldnt get the grains firm - so I cranked up the Dexrin to 5% - but about then I made a new batch of Dex - went ahead and milled 5kg of meal with the new dexrin - its been wet weather here (winter) so the plan was mill meal up when its safest to run the mill, then later when the weather improves we will granulate and dry it - I have been checking small test batches along the way and a week ago I went to granulate some of the new batch - man was it ever gluey!! - could not get this stuff to go through the screen at all so now I am backtracking and remixing to get the Dexrin % down -- I read a post here a while back about trouble with a crook batch of dexrin - well I reckon that has caught me too - TEST YOU DEXRIN GUYS!!

 

Have to say I really appreciate all the accumulated knowledge here - have read as much as I can - my first powder was quite ok - about as good as Wano - but its getting better the more reading I do -

 

another post recently suggested an alcohol water mix for granulating would get faster powder - I made dough balls using 75% alcohol -25% water (not very impressed at that point) they were not firm enough to granulate so I rolled it into a flat cake about 1/8 inch thick and left it to dry - next day pushed it through the screen and dried it properly also did a comparison out of the same batch but water only mix

Whoever wrote that post knew their stuff - shot over the chronograph out of a 44/40 the alcohol stuff got 100fps more than water mix - this is right up there at commercial level

33Grains Wano gets about 1100fps, 32 grains of water mix gets 1120fps, 32 grains of Alcohol mixed gets 1220fps, and 33grains of Goex 5FA did 1200fps neat. --- so grain for grain we beat Goex !!!!

starting to be fun!!

Greyhawk

[Nickmaslo]

The only way to achieve great hot BP that I have been taught and I have verified is by using 100% denatured alcohol and absolutely NO binder.

 

I had a problem recently with my shells not getting over 30 or 40 feet. I made BP using my mill and the usual 75/15/10 formula +5 dextrin. Granulated with 25% alcohol 75% water.

 

Actually Tyrone (above) was the one who I was talking to and trying to figure this all out and he told me it's my BP and it just wasn't hot enough.

 

I found out that I was overcharging my mill and I didn't have enough lead inside either! So I went and bought 200 .50 cal lead shot balls and added 100 in each jar. I cut the amount I mill which was about 10oz in each jar to about 5oz of chems in each and I found I had to mill longer than I was. So I now mill for at least 12-18 hours on each run.

 

Keep in mind there is NO DEXTRIN in the BP mix at all - the binder SLOWS the burn rate down.

 

Once I have the BP milled to a silky smooth talcum like powder. I start with 1oz of 100% denatured alcohol and hand mix it all and keep adding 100% denatured alcohol through a spray bottle one spritz at a time until I get a hard clay like material. One way to check the consistency is to knead it all into a ball and take a knife and cut the ball right through the middle and if it doesn't crumble or crack and it is a clean(ish) slice straight through then its ready.

 

 

A good way to evenly wet BP for granulation is to hand mix it with your wet ingredient and then push it through a 12 or 20 mesh screen. This forces the water into the dry chemicals from passing through the screens.

 

The alcohol , per tyrone, activates the natural resins in the charcoal and allows it to bind very well actually. It's not ROCK hard like dextrin but it's nice and hard.

 

Using the same amount of this hot BP about 1.25oz for a 11oz shell I get around 150 foot apogee.

Edited August 1, 2015 by Nickmaslo

[Ubehage]

The only way to achieve great hot BP that I have been taught and I have verified is by using 100% denatured alcohol and absolutely NO binder.

 

I have been told by Ned Gorski, that even screened (not milled) BP can be hot and effective, when using alcohol only.

I'm gonna try that with my next batch.

[Nickmaslo]

Yeah I'm sure that works as well. I just know that switching to the no binder no water method solved my lift problem. I'm sure screened instead of milled using only alcohol will achieve similar results

[Maserface]

You sure it wasn't the fact that your fired your shell out of the wrong sized gun?

[Nickmaslo]

There was 3 more attempts in the CORRECT sized gun after that attempt. Same flight pattern

[Maserface]

And you are certain that it was the binder?

[Nickmaslo]

I'm certain it was the quality of my BP. 4 shells went the same height. 3 of which were constructed flawlessly and in the correct size and in the right mortar. Whether it was not enough mill time or too much binDer or not being granulated with alcohol I can't say. I want to say probably a combination of all 3. I just know the BP wasn't hot enough before and now without dextrin, longer mill time , and being granulated with 100% denatured alcohol they fly high and fly far.

[Maserface]

Well telling people that "the only way to make bp" is alcohol granulated is misleading. Sounds like your mill setup was far from optimal, and who knows what else wasn't correct.

 

Hot black powder isn't hard to make if your mill is running optimally, your charcoal is reactive, and your proportions are correct. 2% dextrin won't make good powder worthless.

[gregh]

Right on Maser! I make plenty powerful enough pine BP with 2% dextrin and wetting with water. It might not be the absolute fastest BP on the planet, but I make fireworks and don't complete in the BP olympics. Mine is fast enough and more importantly, I have a method and I am consistent with it. I personally believe consistency is more important than all out speed.

[stix]

The only way to achieve great hot BP that I have been taught and I have verified is by using 100% denatured alcohol and absolutely NO binder.

 

Maybe not the best choice of words Nick - "the only way", but don't worry, it's hard to word things the way you want sometimes. Everyone has their method, and as already pointed out, consistency is more important.

 

I'd be interested to know what type of charcoal you are using. Some charcoals have natural resins that are left after the cooking process. Those residual resins could be the reason that you don't need any other binder like dextrin, ie. much like redgum dissolves in alcohol. This is nothing new, I've read it on this forum before.

 

If it works for you, that great - keep it up. Remember that there are different woods and therefore charcoal that may well determine your method.

 

I use paulownia, I've found that I need to use dextrin so it ends up as hard granules - whether I "need" hard granules is the question for me.

 

Cheers.

[MrB]

The only way to achieve great hot BP that I have been taught and I have verified is by using 100% denatured alcohol and absolutely NO binder.

 

There is no only way with few things in life, and certainly not with BP. The alcohol approach only works if there is zap / tar / resin residue enough in the coal to act as a binder.

For someone else, it might not work at all, since their coal is of a different flavor.

 

 

I'd be interested to know what type of charcoal you are using. Some charcoals have natural resins that are left after the cooking process. Those residual resins could be the reason that you don't need any other binder like dextrin, ie. much like redgum dissolves in alcohol. This is nothing new, I've read it on this forum before.

 

If it works for you, that great - keep it up. Remember that there are different woods and therefore charcoal that may well determine your method.

 

To try and claim that there is a only way, with BP... Damn. The variables are so many, that using a different charcoal, you could do the exact same thing, and get worthless BP. I'm glad he found something that works for him, but going that route, is WAY to expensive for my taste. Luckily, i have no issues with my BP other then having to dry everything before milling.

B!

[Ubehage]

 

The alcohol approach only works if there is zap / tar / resin residue enough in the coal to act as a binder.

For someone else, it might not work at all, since their coal is of a different flavor.

I have read that Red Gum also works as fuel. So, will it help to add some Red Gum?

[Nickmaslo]

Well telling people that "the only way to make bp" is alcohol granulated is misleading. Sounds like your mill setup was far from optimal, and who knows what else wasn't correct.

Hot black powder isn't hard to make if your mill is running optimally, your charcoal is reactive, and your proportions are correct. 2% dextrin won't make good powder worthless.

My fault didn't mean to put it like that, I meant ' the way that worked for me that fixed my issue'

[Nickmaslo]

Maybe not the best choice of words Nick - "the only way", but don't worry, it's hard to word things the way you want sometimes. Everyone has their method, and as already pointed out, consistency is more important.

 

I'd be interested to know what type of charcoal you are using. Some charcoals have natural resins that are left after the cooking process. Those residual resins could be the reason that you don't need any other binder like dextrin, ie. much like redgum dissolves in alcohol. This is nothing new, I've read it on this forum before.

 

If it works for you, that great - keep it up. Remember that there are different woods and therefore charcoal that may well determine your method.

 

I use paulownia, I've found that I need to use dextrin so it ends up as hard granules - whether I "need" hard granules is the question for me.

 

Cheers.

 

I use huge bags, I think 2 cubic feet of red cedar pet bedding. It's like 7$ or something at Walmart. I have a 6 gal TLUD that does great. When I mill the charcoal it's usually for at least 6 hours. I'm not sure why I don't need dextrin but the final product is fine, holds well. I mean sure if you just sat there and shook the container for 10 minutes it probably wouldn't be 2FA anymore LOL

[gregh]

I have read that Red Gum also works as fuel. So, will it help to add some Red Gum?

 

When you start adding fuels, it changes the fuel/oxidizer ratio. You would need to work out the stoichiometry and make adjustments for optimal burn. However, since charcoal is so much cheaper than red gum, I would stick with it as my fuel source.

[deepdixie]

Overall, no one's mill should be that hot. If it's melting, it's from localized heat generated from impact. I'm not convinced this is happening though. Moisture from the nitrate, charcoal, or even the mill jar could all be culprits.

 

For me, it was mostly the charcoal. My nitrate was prilled and relatively coarse, so I milled most compositions (the safe parts at least) containing it for a little bit. When making polverone using commercial airfloat, it came out a free flowing powder. When using willow for hot BP, it clumped almost every time. There was a difference in milling time too. Lots of factors, just passing on my experience.

Just finished a 5 hour mill run today using Black Willow Charcoal for the first time. My mill is charged with optimal media load and turning at 75-80rpm. The powder caked up multiple times during the milling operation, even after 1 hour of milling. I constantly had to stop milling and uncake the jar. I tested a small amount of powder after the 5 hour run and it wasn't near as fast as the BP I had made for the past two years using Airfloat charcoal. My chems are dry and stored with dessicant packs. What gives?

[Ubehage]

Just finished a 5 hour mill run today using Black Willow Charcoal for the first time. My mill is charged with optimal media load and turning at 75-80rpm. The powder caked up multiple times during the milling operation, even after 1 hour of milling. I constantly had to stop milling and uncake the jar. I tested a small amount of powder after the 5 hour run and it wasn't near as fast as the BP I had made for the past two years using Airfloat charcoal. My chems are dry and stored with dessicant packs. What gives?

I have read and heard experienced people say that "BP will tend to clump when balmilled".

However, in my own experience, I only had clumps when my ingredients weren't completely dry.

Edited November 12, 2015 by Ubehage

[deepdixie]

I even reduced the amount of Dextrin in the mix from 5% to 2%. The Dextrin is milled with the other ingredients from the start of the operation. Would it be best to add the Dextrin only after the milling of the 75/15/10 is complete? In the past I milled Dextrin along with Airfloat Charcoal and never had any clumping issues. I would always have a free flowing powder when I emptied the milling jar.

[deepdixie]

I have read and heard experienced people say that "BP will tend to clump when balmilled".

However, in my own experience, I only had clumps when my ingredients weren't completely dry.

I do live in an extremely humid climate but I take the proper measures to ensure that my materials are protected from the elements, to the best of my abilities anyhow. Its funny how I had better results with a less powerful charcoal. Perhaps I need to oven-dry my ingredients before milling.

Edited November 12, 2015 by deepdixie

[Ubehage]

I do live in an extremely humid climate but I take the proper measures to ensure that my materials are protected from the elements, to the best of my abilities anyhow. Its funny how I had better results with a less powerful charcoal. Perhaps I need to oven-dry my ingredients before milling.

Don't dry charcoal in the oven inside your home. It can smell very bad.

[stix]

Apart from your chemicals containing moisture, ceramic ball media can also introduce unwanted moisture.