Stainless/Brass Media?

[Maserface]

Hey what about soldering stacks of pennies together? Pre 1982 pennies are mostly copper.

[NeighborJ]

I had thought of tig welding the nickels together but the whole point of using the nickels in this case is to get more flat sides sliding across each other. The nickel drum has a toothpick super glued to the inside so they tumble every once and a while. I'll remove it later with acetone. Edited August 12, 2016 by NeighborJ

[DavidF]

I think that this will be replicated quite fast. If not by any others then I will for sure. But I think we will need more details on the process. You're using a 3" jar? Size/volume? And do you just screen in the sulfur? Pre-milled or flower? Have you tried milling it together with the charcoal?

 

As for milling KNO3 you could try 1% of charcoal as an anti-caking agent. It's not enough to constitute an explosive mixture and it does make a much more free-flowing product.

 

It's not a 3" jar, it's what they refer to as a 3lb jar. The ID is 4", and it's about 4 1/4" deep.

This experiment just kind of exploded into being. So I'm all over the place in my thinking so far. Originally, I proved (all to myself, my proof is) that charcoal milled with the 5/16" S.S. media in the Rebel 17 jar (500 gram batch size) made great screen-mixed nozzleless rocket propellant. Then I got coached to make the black powder into properly dense, pucked, corned and graded form. Then I made a batch that way and compared it to Ned's on Fireworking.com. He has a bunch of results in his article on baseball testing. I made a few more batches with different charcoals, all good.

 

Something in me made me decide to try the rock tumbler for milling the charcoal, since the larger jar worked so well. I milled 50 grams. Again, success. So I tried coarser willow charcoal (+12 mesh). Again, success. Geez, how do I make this not work? 1/4" media worked, and 3/16" media worked- at least they worked to make the charcoal superfine. The powder has yet to be tested. Also, I thought that maybe the media wouldn't work on harder charcoal, like say, +12 mesh oak. I went for the 3/16" right away this time Yup, talcum powder- and VERY black, like all supermilled charcoals I've prepared. (EDIT: got a bit ahead of myself there on the oak. Yes, talcum powder- with chunks underneath. What did I expect, the media was smaller than the charcoal!)I should have screened the jar before I shot my mouth off. That's where I'm at so far. I did not intend to do all this monkeying around, just for the sake of "knowing" but here I am. I have more batches waiting to be prepared yet. I really didn't think I'd have this much success. But since I have, I'm rolling with it. I will have a complete report in a couple of weeks when I am done testing and I can write up stuff in a more organized way.

 

I read something about nickels once a long time ago but I forgot about it. I guess we'll know shortly how they work. I'm glad you guys are dipping a couple toes in the water on this thing. Thanks for at least checking it out.

Edited August 12, 2016 by DavidF

[NeighborJ]

These milling tests are getting complicated. While I wait for the last two samples to Finnish milling I've decided to make a spreadsheet to outline the milling process for each sample and post test results. I'd like to test each sample twice to ensure accuracy but this is starting to turn into a lot more work than anticipated.

If DavidFs test results come back with irrefutable proof of improvement then I plan on cutting up 3/16" stainless(316) tig welding wire into tiny cylinders for my media. I suspect that the only reason that the tiny media may work better is because it hammers all the way into the corners of the mill where the larger chunks tend to hide. The nickels also sweep into these corners so it stands to reason that they should yield similar results. But again this is why I'm testing.

[DavidF]

" irrefutable proof of improvement..." Ha ha, I don't know what that means! My proof (to me) is that I have made very good milled black powder for years now. I've mostly used it for nozzleless rockets and burst. When I switched from my original ceramic in PVC Sponenjars to brass, I got improvement. I got 'some' more improvement by pre-milling the charcoal. I tested my powders with end burners, and also with nozzleless BP coreburners. As soon as I switched to the 5/16" stainless steel media I got quite an improvement in peak thrust. Yes, that was with milling the BP with the stainless. I did it, but I do NOT recommend it- just in case.

 

Then, a pyro newbie made nozzleless rockets with screen-mixed powder- after I told him it would never work. He absolutely refused to mill black powder with any media! So I started experimenting. I will say, at that time I was judging all my powders with the Acme, and considering peak thrust only. So I was really only looking at burn speed, not impulse.

 

A member on FW got a rocket test result that I found very curious. He claimed it was from a nozzleless rocket. The motor had a .75 second burn time and lots of thrust. I could not (and still can't) see how those things can go together. So I started experimenting with screen-mixed propellant. The thrust was great, but the burn time was too short. So I started doing things to stretch out the burn time, like using coarser charcoal, different charcoal, wax, water granulation, anything I could think of. Getting the burn time to go up cost me impulse every time, and I was never able to duplicate the performance curve I sought (for no real reason) to copy.

 

What I did learn though, is that my red oak-based screen-mixed black powder propellant worked just as well as most of the milled powders I had ever used. And the powder was fast! The red oak charcoal was milled with the 5/16" media. I ran out of it though. So, I took other charcoals that were milled with the 'peas' and did more rocket motor tests. All good. That's when I was encouraged to puck and corn my powders and do baseball tests instead. Many pyros don't do rockets, and many of those who do, don't have test stands. But all pyros use lift. So I started in this direction.

 

I don't offer the above ramblings as any kind of proof of anything. I just thought I would give a bit of the back story- show my thought process, so to speak. I think if we all do our own things, have discussions and compare notes, collectively we can do great work. I'm looking forward to any results of tests other members do. I'm looking at my change jar in a whole new way now

[NeighborJ]

OK the preliminary spolette tests are in, minus two samples still in the mill. It shows the nickel milled spolettes finishing quicker than equally milled brass. The two nickel ones are #2 and #6. So far it out performs the brass with equal mill times. I'm milling with brass to get an idea if any amount of extra mill time will improve or equal the nickel results.

Correction, if ingredients are milled separate the nickels work better. If the ingredients are milled together the brass is better, I somehow missed the #3 spolette burnout first. The two with the long burn were milled separate then screen mixed.

If you are looking for a way to make screen mixed nozzleless motors you will need to make your own tooling but it works just as you described, long burn with sustained thrust. The spindle can be tuned for slow propellant just as they can be tuned for fast ones.

Testing will need to wait because I have tickets to the Steelers Lions game tonight. here we go stillers here we go.

Edited August 12, 2016 by NeighborJ

[Nessalco]

Dave, I think I'll be looking for some small SS media - I've seen the results of your experimenting....

 

KO

Edited August 13, 2016 by Nessalco

[NeighborJ]

Nessalco, from what I've seen of these two milling medias, I can safely assume they each have their specific purpose. I will still need the brass for breaking up kno3 prills, the nickels are extremely efficient for charcoal only. I believe tomorrow I will buy some 1/4"and 3/16" brass rod and cut them into media, they will likely replace the nickels if they are effective at milling granular kno3. I expect it will become my go to media. If anyone wants me to complete all the tests I will, but I've seen enough for convincing me.

DavidF I do believe the pressing and corning will skew the results because you are using two kinds of homogenization methods. Before I had my mill I would use a double corning process with screen mix and it was entirely effective with lift and burst. It would force the kno3 and sulfer into the charcoal even though it still had larger mesh charcoal.

[kevins]

 

It's not a 3" jar, it's what they refer to as a 3lb jar. The ID is 4", and it's about 4 1/4" deep.

This experiment just kind of exploded into being. So I'm all over the place in my thinking so far. Originally, I proved (all to myself, my proof is) that charcoal milled with the 5/16" S.S. media in the Rebel 17 jar (500 gram batch size) made great screen-mixed nozzleless rocket propellant. Then I got coached to make the black powder into properly dense, pucked, corned and graded form. Then I made a batch that way and compared it to Ned's on Fireworking.com. He has a bunch of results in his article on baseball testing. I made a few more batches with different charcoals, all good.

 

Something in me made me decide to try the rock tumbler for milling the charcoal, since the larger jar worked so well. I milled 50 grams. Again, success. So I tried coarser willow charcoal (+12 mesh). Again, success. Geez, how do I make this not work? 1/4" media worked, and 3/16" media worked- at least they worked to make the charcoal superfine. The powder has yet to be tested. Also, I thought that maybe the media wouldn't work on harder charcoal, like say, +12 mesh oak. I went for the 3/16" right away this time Yup, talcum powder- and VERY black, like all supermilled charcoals I've prepared. (EDIT: got a bit ahead of myself there on the oak. Yes, talcum powder- with chunks underneath. What did I expect, the media was smaller than the charcoal!)I should have screened the jar before I shot my mouth off. That's where I'm at so far. I did not intend to do all this monkeying around, just for the sake of "knowing" but here I am. I have more batches waiting to be prepared yet. I really didn't think I'd have this much success. But since I have, I'm rolling with it. I will have a complete report in a couple of weeks when I am done testing and I can write up stuff in a more organized way.

 

I read something about nickels once a long time ago but I forgot about it. I guess we'll know shortly how they work. I'm glad you guys are dipping a couple toes in the water on this thing. Thanks for at least checking it out.

 

Dave, how many pounds of 5/16 SS media did you use in your rebel 17 jar?

Thanks, Kevin

Edited August 14, 2016 by kevins

[DavidF]

NeighborJ, I do think the pucking and corning is a big thing too. I look at it this way: I'm making the powder as slow and dense as can be- and it's still good. I'm sure that the water used in pressing is a major advantage as well. Keep in mind if you would, I undertook this to see if I could mimic the performance of commercial powder with screen-mixed powder. It wasn't about comparing my screen-mixed powders to my ball-milled powders. That's a whole 'nother bunch of tests;) When will I ever be done testing stuff?

 

kevins, I used 30 pounds. That's 6600 balls. I got them originally in boxes of 2200, so I used 3. That's a bit more than half full. Chunky charcoal likes to collect in the flared area where the boot meets the seal from the lid, FYI. That's about 250 bucks worth from Craig Ball Sales.

[kevins]

Thank's Dave

 

Kevin

Edited August 14, 2016 by kevins

[LiamPyro]

I feel like the "ultimate" way to mill might be with 5/16" brass balls (heavier + safer than stainless), and to mill the components separately and then together. I also found a potentially way more cost effective option while browsing on Craig's. They sell 1/4" nickel plated low-carbon steel balls, $4 per 1,000 (I had a double take at the price). My only concern would be that the plating might wear off eventually, exposing bare steel. Also, I don't know if nickel is safe to mill with in the first place (I'm looking to get media that I can safely 3-component mill with). Edited August 17, 2016 by LiamPyro

[Fulmen]

The plating will most likely wear/flake off fairly fast. Nickel is more ductile and adheres better than chrome, but I still doubt it will last. And as nickel is hard it won't be safer than steel. Hard media can cause point ignition even if it's spark proof.

For milling BP I would not consider anything harder than brass, soft bronze or lead.

[LiamPyro]

Looks like I'll have to go with brass, although it's a big punch to the wallet. My current plan is to get 600 maybe 700 5/16 balls. I'll let you guys know how they work (assuming I follow through).

[Boophoenix]

Mass, what would you think of this for a second party test?

 

Dave, do you think there'd be any value in this comparison?

 

I'm contemplating testing Dave's findings with commercial airfloat? Which I suspect will show the same results to the degree commercial airfloat will allow. This way anyone can compare to a close proximaty taking a lot of the charcoal variable out of the equation somewhat. What I thought I might do is use the same mill ( which can be a small Plastic jar mill or a stock HF mill ether one ? ) for all tests and try 1/2" lead, 1/2" stainless, and the 5/16" stainless 3 component milling and individually milled. It'll take a me a minute to figure out the pressing and corning, but it's the best way to get comparison data by removing the granulating variable.

 

I did some 3 component milling with +60 alder not long ago for just a couple of hours with the 5/16 and it was some of the fluffiest material I've removed from a mill.

 

I really like the magic peas except when they get spilt. They are a pain to clean up since there are so many of the little critters.

[DavidF]

Boo, that's not the way I would go about it. But, there's nothing to say we are all looking for answers to the same questions. I wanted to know if I could mimic or exceed the performance of commercial black powder with single component milling. Yup. So then I wondered if I could do it with a toy rock tumbler (concentrating on charcoal). Yup. Okay, but what if the charcoal was coarse? Yup. Smaller media? Yup. Hard oak charcoal with tiny media in a toy rock tumbler? Hmmm, not so much

 

The next thing for me is to also mill the nitrate with the rock tumbler, and test the speed of that powders made with it. The nitrate does not mill as well as I would like with the small jars. I don't blame the media. There is very little 'fall', and the total weight of the media load is quite low. As I blabbed about before, I see the media load and container as a 'system'. Common sense and experience tell me that a 4" diameter jar does not mill as well as a 6" diameter jar.

 

I didn't write all this to make it 'all about me'. But, I think the folks reading are not curious to a fault like we are. They want THE answer. What's the best media? My experiments show what can be achieved by milling the charcoal in a rock tumbler. The nitrate was milled in a larger jar. So, my information is incomplete still. I've done lots of tests, but I'm out of the batch of willow charcoal I did many comparisons with. Now, I have to use a different batch of charcoal to evaluate the milling efficiency of the different media for milling potassium nitrate with a rock tumbler. Only then can I say which media (of what I have) works best for single component milling, on a beginner level. Whatever works with a rock tumbler will work mo' better with a bigger jar. And the answer might be different for the charcoal and the nitrate. But maybe the slightly gritty nitrate makes hardly a difference worth mentioning? I don't know- yet.

 

So, since my focus is on single component milling, and LiamPyro's goal is 3 component milling, my findings are not really relevant to him- or even to most pyros! Lots more work can be done to better understand black powder, and our various methods of preparing a product that suits our individual needs.

 

Due to the regular admonitions about milling black powder with stainless steel, I wouldn't suggest bothering to test it with 3 component milling.

 

Another thing to consider is speed. I modified my rock tumbler as shown on Ned's tutorial on FW. But his was a Harbor Freight, and mine's a Lortone. His speed was some where around 90 RPM. Mine is only 75. Lloyd's book suggest 92 RPM for a 4" ID jar.

 

And just when I thought I was halfway to knowing everything, I got into a new bag of tech grade nitrate from Norway. Well, Greenhouse grade it ain't! It's whiter, dustier, mills better even in the heat... Where has this stuff been all my pyro life? Damn, back to square one on removing variables.

 

All this rambling has a purpose, I hope. What I'm trying to say is that my experiments are done from my perspective, and do not necessarily or completely apply to others. Boo, if you do your tests with the airfloat, they will be just as meaningful as mine, I'm sure. They'll just be a fresh different take on a subject there's plenty more to learn about. LiamPyro, you might change your tune when you price the brass balls. But if you do get an affordable price, let us know, please!

[OldMarine]

Dave and Brad,If ya'll don't coordinate your tests, I feel pyro may be missing a grand opportunity! Though I've only met Dave from his postings and various PMs, I've met Brad and he's nothing if not meticulous in his 'sperimentation!

Though I would think that controlled tests with various woods would at least lead to some sort of consensus on charcoal/BP production, I realize consensus isn't scientific (see global warming) but if your tests are repeatable they will be a firm base from which to proceed.

[Boophoenix]

Dave, I personally think you've found something awesome with the single component milling. I think it's near a game changer for anyone wanting to lower the risks a little of making good BP.

 

I wouldn't even include the 3 component milling, but to do so with the standard lead I think does have a place in the tests for some comparison. I can easily compare the Geox of 2fa, but doing a batch like the Jones's sets a baseline as the normal standard I believe is milling with 1/2 lead media. I think my plastic jar spins around 74 RPMs and the HF is stock. I do think I'm gonna end up with a mediocre finished product from the Charcal source, but anyone that wants to compare data and results could get involved that way without a charcoal variable. Many of us from the US are using the same brand of I think KNO3. Most of the commercial airfloat comes from one source from what I understand no matter who the vendor, but I could be wrong on that.

 

I've got a lot more testing planned as we've discussed in the past. To me this would have some value as a baseline. I see it as OM or anyone else could make a batch of commercial airfloat BP and it should match nearly to what I find. He could then test some cedar that is so abundant in his area. For newbies a baseline from commercial mixed materials could answer some questions over comparing to purchased BP's in my opinion. My next round of testing would be from all the same wood source material coked by me to narrow down some of the things we've discussed before. If I find what I want to with one wood what ever it be I'll then move to a second wood source. If the second proves the same as the first a third would confirm those results enough for me to start tinkering with a wider variety of woods.

 

I'm more than happy to try any testing you'd like to see if we can pair our results. I think that distance thing along with if we can have common results that repeatable kind of removes a lot of the doubt.

[NeighborJ]

I do believe there are still some of us still doing various testing. I for one am still very much involved in my own experiments. Only I've been trying to improve the efficiency of my large bucket mill, which does not provide the same results as the HF tumbler. Each mill does require different media, different speeds, and these also change depending on what component,variety and how much. I'm getting dizzy watching mills and am getting lost in these tests. I've improved my bp beyond what is necessary and am making more of it than I can readily use.

My point is these experiments are purely what works for your process and will not always work for the next guy and his equipment. I still think that each person should evaluate his own process once in a while to look for improvement. I think it is foolish to assume that we can come up with a new media or process which will work for everyone.

[OldMarine]

A process which would enable the average suburbanite to safely produce usable BP would be an award winning accomplishment in my humble, suburban opinion!

[NeighborJ]

There has never been nor will there ever be a process which can guarantee safety while making bp. At some point it all needs to be mixed together and the goal is to make it as fast and hot as possible. We have relatively safe methods for making "usable bp". Ultimately each person needs to own up to the reality that this has potential for danger, and ask himself if the consequences and not the odds are acceptable.

[Boophoenix]

Neighbor, you bring up some good points. At the same time though many start off with an Harbor freight tumbler. The next upgrade if ya don't build a mill is the tumbler or rebel 17 5 quart hexagon jar. In my mind this makes my process and Dave's even though he's a Canuck and I'm in TN the same there. The change comes in with our supplies. With Charcoal being a huge variable which is why I want to do the baseline with commercial airfloat. I also think a newbie could benifit from commercial airfloat baseline data. ( I'm a newb and I made this really awesome BP that goes woosh with my secret charcoal and I've never made BP before. Is my woosh the same as yours? Baseline data may could answer that with the right tests )

 

I don't think the goal should be the hottest powder. It's not my goal. I'm looking for a good serviceable charcoal and what I can do to make it preform the most consistenltly. I'm gonna push limits in certain direction while I tinker with mine to help the next guy though. I do want the best preformance I can get from my chosen source as it'd be a little silly to not optimize things a little.

 

Now to contradict myself in the above paragraph. If you're a rocket guy looking for the ragged edge then the hottest may be what ya want.

 

The comercial industry has survived a long time on a consistent powder that isn't particularly hot. So my simple mind sees it as finding a good material you can source locally for your uses if you wanna cook charcoal. I don't know if I've asked this question before, but Dave may have. Does Estes use any specialty source wood for charcoal ( doesn't mater what the wood is though ).

 

Many of us work with this art on our own for the most part in the beginning. Up until recently I had to travel 8+ hours to compare anything with anyone in person. Dave's testing to out preform commercial powder is a good one for sure. My goal with the baseline is if a newb can't produce the baseline with his results he has a process error. When the process is stabilized then the charcoal experiments can proceed.

 

I've followed a lot of Ned's posts and thinking and Lloyd's too. Ned makes a good point of two charcoals a hot and a standard with materials he has easily available. Lloyd makes another good point add a little more with what ya have to work with. Aside from rockets and breaking a shell Lloyds seems pretty simple one powder fits all. If ya need some more ump amend the BP a hair.

 

Since I'm new here some may not know me from other forums. I'm fascinated by charcoal and it's variable on BP. I wanna run some tests to find some things out for me and to share about cooking temps of charcoal and how they effect it's Performance. I'd like to share what I figure out in case anyone is interested as I go, but if no one is we can PM and email result between those of that are. In the end I'm gonna do my testing for my own piece of mind so the only thing that changes is do I take the time to share publicly or discuss with the people that are interested privately.

 

Currently I shoot more liquid fireballs than anything else and the hottest powder isn't what I want. I can adapt to use it with additional costs though. Maybe someday I'll grow ino canister shells which I don't think like really hot powders either.

[NeighborJ]

Charcoal cooking temp is certainly a variable which I have not looked into. I do know that my hottest bp ever came from a batch which was not completely cooked so I used what would break off and cooked the rest in another batch. This can tell me only limited amounts of my process without the use of a flu gas analyser. I know I can make it faster but like you said I need a consistent product, so I completely cook my coal and mill it to the best of my ability and have a nice and repeatable bp.

I would certainly be interested in the coal cooking temps but perhaps it should be on a separate thread.

[LiamPyro]

Once I get around to doing some testing of my own, I'll try to write up a relatively complete report on it and share for anyone who's interested. By the way DavidF, I'm not disregarding your idea of individual component milling, the reason why I'm thinking of buying brass is just to give the option of 3-component milling. That way, I can safely test individually milled powders alongside 3-component milled ones using the same media. You're findings are actually very relevant to me, as I don't exactly have an ideal place to run my mill and making things safer would be a huge plus.

[LiamPyro]

Hopefully I can bring this topic back from the dead, it's been a while.

Update: I bit the bullet, purchasing 600 5/16" brass balls, for a grand total of $80. At the moment, I'm using them to mill 50g willow charcoal in a modified rock tumbler. I ran it for a solid 6 hours, but realized that the charcoal was clumped at the bottom of the jar due to moisture. I dried it in the oven and just tossed it back in. I'm gonna mill it overnight, considering it probably spent the majority of the previous 6 hours just sitting. My plan from here is to split up the charcoal and make two batches of BP, one screen mixed and one 3-component milled. I'm going to mill the KNO3/sulfur (not sure if together or separate) for the screen mixed powder for probably around 3 hours. I'll keep posting for anyone interested.