Air Float Charcoal Black Powder

[snapper]

now try alder, paulownia, eastern red cedar or black willow. white Pine makes ok BP but any of the woods i suggested will be much faster

[Steigede]

Yeah! Definitely.

[Arthur]

In Europe Balsa and grapevine are the charcoals used for the fastest powder. However well made powder from willow or red alder and the goto standards. If you have a slow batch then either consign it to fountains or mix it with a much faster powder to make something more normal. Get to know the flight time of a ball from a mortar with your powder, if you make a slow batch then make a fast batch and mix them.

[SharkWhisperer]

It was totally the charcoal! Here's a quick video of the difference. I made some pine charcoal over the weekend and whipped up a new batch of black powder. Milled for roughly the same time.

Your pine charcoal BP looks like it could have multiple utilities, particularly if wetted & granulated/riced (was it fresh from the mill?). Your "airfloat" charcoal BP has a long life ahead in making various gerbs/fountains. But, you might be able to speed it up to another utility if you wet-granulated it. On a 1-10 subjective burning speed scale, wet granulating after milling generally increases my BP burn speed by about a single notch (takes a 6/10 I'd judge your AF BP to a 7; and an 8/10 I'd rate your pine to an 8.5 or possibly all-around usable 9). But if it's already wet-granulated (don't recall prior posts) then that's just what you have as an end product.

 

I'd take others advice about ERC (cheap, fast BP) or stick with your pine, depending on how you treated it. If from the mill, then retest after granulation--maybe you'll be happy with what you have with your pine--looks fast enough for most applications. Else granulate and test and try to wipe the smirk off your face cuz it'll be much faster.

 

The airfloat? Great for slow-burning stars and whatnot, but not for lift, burst, maroons, or essentially anything else in pyro except gerbs and slow blackmatch.

 

Good work.

[Arthur]

I did once read that USA manufactured BP was made from Maple, can anyone confirm or positively refute that please.

 

Once you change the ingredients you have to recheck that the process times remain optimal. It may well be possible to make fast enough powder from the hardwood powder by extended milling. One suggested test method is to start with a full mill and take a sample after several times say 2 hours then after additional hours. Then keeping the samples separate puck and corn (or wet and rice) each one and check that the powder is OK and at what mill time no significant improvement occurs. The easiest test is to launch a small ball (cricket ball or baseball) from a suitable mortar and time the flight achieved from a moderate but carefully weighed charge. Beware, that ball will land somewhere.

[justvisiting]

Arthur yes, maple. Oak is also used. Yes, oak. Juniper (ERC) charcoal probably makes the hottest powder with the least effort for amateur fireworkers. I've known balsa to make very hot powder, but it's not worth the aggravation, IMO. Vine charcoal is used of necessity, not because it makes fast powder. Also, I believe the Maltese deviate from the 'standard' 75-15-10 to get better performance out of it.

 

One thing I found over time is that the performance of screen-granulated powders is extremely variable, compared to the performance of pucked, corned powders. If I wanted to measure differences between production methods or charcoals, I'd always use pucked, corned, graded powders.

 

As far as mixing faster powders with slower powders to get consistent performance- that's what the manufacturers do

[MinamotoKobayashi]

From Pyropowders.de I have found two kinds of fast charchoals: juniper and oak, but they are very expensive (16.50 dollars/kilogram).

Also the delivery costs are proibitive, but I wish to try to replace the Pyrogarage pine charchoal with one of the the above mentioned charchoals, at least for my hot BP.

Justvisiting, in Your modest opinion, it is better oak or juniper?

[justvisiting]

I'd go with the juniper. Really though, I'd be surprised if you can't find wood locally that would be good for fast BP.

[MinamotoKobayashi]

Yes, I can found good wood here, but I do not know how to create charcoal. And I haven't the place to do it.

[Steigede]

Yes, I can found good wood here, but I do not know how to create charcoal. And I haven't the place to do it.

Couldn't you stuff a coffee can with it and buy a cheap $10 electric burner? Set it up outside?

[justvisiting]

MinamotoKobayashi, I have seen your tooling and your pyro. I have no doubt you can make your own charcoal I think you would really enjoy having more control of your processes. One big problem is the amount of smoke that's produced when carbonizing wood. The smoke can be burned as it's produced. If you have access to the juniper pet bedding popular in North America, you have a ready-made raw material. You don't get much each run, but it's quick and easy. Here, it's called Eastern Red Cedar.

 

This site has a lot of info on charcoals for BP:

 

http://wichitabuggywhip.com/fireworks/charcoal_tests.html

 

I've found various woods that make good BP charcoal around here (southern Canada). We have black and other willows, northern white cedar, and staghorn sumac (my favorite). It's been said quite often that partially rotted wood makes good BP charcoal. I've been tempted to just go collect some deadfall in the forest or even light, decayed driftwood from the fresh water beach.

[MinamotoKobayashi]

The majorn concern is not to mill the charcoal pieces, but make a good charcoal directly from the wood without the creation of ashes!

[kingkama]

The majorn concern is not to mill the charcoal pieces, but make a good charcoal directly from the wood without the creation of ashes!

Not so hard, take a old varnish container and cook Charcoal inside, provide at least 1 hole for vent gas of distillation.

[snapper]

stay away from oak, it requires extreme milling to get good results and it has high silica content. softer woods like cedar, juniper, paulownia are far easier to process requiring much less hammering force to get good results.

[MinamotoKobayashi]

Thanks for the hint, snapper!

[Arthur]

If you cook charcoal over a flame you can direct the very smelly off gasses into the flame where the smell is burned up, If you heat with electricity you have to be fare enough away that no-one smells it and complains.

[Merlin]

This works for me. I get 10 to 12 seconds flight tine with 25 grams MCRH and a baseball. There is no need to crush or mill the charcoal. I made a TLUD if I can literally anyone can. Look up instructions for building a TLUD. Lowes has every thing needed. A couple 5 gallon metal buckets, an expansion collar and a short piece of stove pipe.

Then go to Walmart or a pet store and get a couple bags of Red Cedar pet bedding. Once cooked down which take 6-8 minutes per 5 gal bucket dump into second bucket and seal from air with lid.

Repeat all you want. There is no need to grind or mill- just weigh the charcoal and add to mill with Sulfer and potassium nitrate. The charcoal shavings are so thin and fragile they very quickly reduce to air float in the ball milling process. Im just saying this quickly produces very good charcoal for BP. I use MCRH but granulated is fine. Commercial Airfloat is good for stars but useless for good BP. Also a correctly made TLUD produces very little smoke or foul smelling gases. Add a match and the erc is its own fuel. No building a heat source to cook it.

Edited July 21, 2020 by Merlin

[justvisiting]

Here's a little experiment I did in an attempt to add data to the oft-repeated statement that commercial airfloat charcoal makes crappy lift. BTW, I agree that it usually does. Since I am in Canada, commercial airfloat charcoal was not available to me at that time. I chose a charcoal that was most similar to airfloat in Roger O 'Neill's charcoal study in Pyrotechnica 17. It's mesquite, the charcoal just above airfloat on the chart that follows. I milled it extensively in a small hobbyist mill, which is (some of) what was done in that study. I don't disagree that there are better charcoal choices than commercial airfloat for lift. I don't disagree that using the 'better' charcoals is more efficient, and less time and labor are needed to produce a good product. ERC is an excellent choice, as others have pointed out. What follows is one of my small parts of a very lengthy exchange. I didn't do the work to prove that using 'sub-par' charcoals make great lift. I did it to dispute the statement that sub-par charcoals (like commercial airfloat or mesquite) can't be made to function as lift. That statement has been empirically disproven, and the article detailing that work has already been linked to elsewhere. Here is my excerpted portion of the discussion where I test out my new hot water bath method. Since I'm only posting my own personal work, I don't think copying from Ned's forum to here is an issue worthy of concern.

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OK, I am not presenting my work on this as an entry to win the prize. Besides, I already have a lifetime membership The thing that prevents me from entering is the lack of availability of the ubiquitous 'airfloat' you all use, up here in these parts. I decided to do the best I could with what I have, with the hope that my tests will move the BALL up the field a bit, so the winner can get a touch down.

What follows is an international effort involving Mexicans, Americans, The British, and a Canadian. Lacking commercial airfloat, I chose to use the charcoal that I can get that comes the closest in performance, According to Roger O 'Neill's testing in Pyrotechnica 17.

Enter the Mexicans.

This stuff is the hardest charcoal I've ever seen. It's like rocks. I ran it through the Waste King garbage disposer Caleb brought me from the US. I thought the charcoal was going to break it before the bag was done! The +20 mesh product was run 100 grams at a time through my bullet grinder. The mixed mesh sized charcoal was then milled for 6 hours in my handy dandy Pyro-Gear mill. I love this thing!

I can run this thing anywhere, like in the trunk of my car in the rain. The milling media I used is- you guessed it- the 'magic' peas, that Bradley B. so kindly sent me. These are 5/16" stainless steel bearings that are truly the very best thing you can use to reduce coarsely milled charcoal to a very fine state of division.

The crystalline potassium nitrate I have was milled with 1/2" media of the same type in a different jar. I milled it for 2 hours, around a half a pound (250 grams) at a time. The sulfur used was rubbermakers H10, straight from the bag. Next, the 3 components were blended by hand and run twice through a 40 mesh screen. the batch size was 300 grams, of the 75-15-10 variety. My first batch was made without binder, but I was unsatisfied with the granules. The following 2 batches were granulated with 2% additional dextrin.

Now it starts to get interesting. I considered Mike Swisher's statement that he can lift small shells with his boiling water polverone, using charcoal that was not special. I assumed Mike meant commercial airfloat charcoal from Service Chemical. Mike's statement gave me great confidence in my mesquite charcoal, because it was milled much more finely than regular airfloat charcoal.

The key to using the hot water method is the extreme solubility of the potassium nitrate in hot water, compared to cold water. Ned's past tests didn't seem to indicate any great value in using hot water (for black powder, tested in spolettes). This is uncharted territory for me. I decided to use 50 grams of water to moisten each of my 300 gram batches for granulating. The water was heated to almost boiling, and dumped into a medium Ziploc freezer bag that contained the powder- the baggie method, all over again This amount of water was nowhere near enough to get a proper texture for granulating UNTIL I soaked the closed bag of dough in a pot of very hot- but not boiling- water. I just floated the bag in the hot water, and took it out to knead a couple of times. In 5 minutes or so, enough of the potassium nitrate had dissolved to make my mixture into a soft putty. At this point, the bag was removed from the water, toweled off, and left to cool a bit. As it cooled, I could feel the dough getting stiffer. I made it into a blob in the bag. Then the blob was removed, and rolled into a glistening black ball.

The ball was left for a few minutes to cool further. The shiny surface dulled as the nitrate began to precipitate, and the ball became much more stiff. I grated the ball through the screen in the picture above, which took a little elbow grease due to the stiffness of the ball. But I have a bum arm, so for most folks it would be easier, I would guess.

The granulated powder was left on the newspaper shown for a few minutes to stiffen up further, and then run back through the same screen again to de-clump. The paper barely got damp, because of the small amount of water used in the process.

The powder was left for about half an hour to dry up a little more, and placed on paper on a food warming base set on low. The temperature of the warmer was maybe 140 degrees Fahrenheit. I left it for an hour or so, and ran it back through the screen shown earlier to declump. Then I shook it on a 20 mesh screen to remove the fines, which added up to around 50 grams. The resulting powder looked like this:

I made 2 batches, of 306 grams each (6 grams was dextrin). The first batch was your run of the mill screen 75-15-10. The second batch was 70-20-10. Trying 70-20-10 was not an original thought of mine. I thought back on the several times Bradley mentioned Ken and Richard's (the Brits) black powder articles in AFN. Their work seemed to indicate that if black powder was made with a 'sub-standard' charcoal, performance could be improved by bumping up the charcoal percentage. Since I felt that my mesquite cooking charcoal fell into that category, I thought I'd give it a shot. After all, I was asking a lot of this powder. It was the least I could do. To be honest, I had doubts. Anyway, I now had 2 different powders, made with the same ingredients, but in different proportions. I got out my trusty baseball tester.

It's got a bubble level on top, and I use it in the field in the background. The powder is weighed and put into a lift cup. It's ignited with thin black match that has a visco leader. The match is taped into the cup so it can't move. The flight times are measured with a regular stopwatch. I painted the balls black because they are easier to see in the sky.

The powders were tested the day after they were prepared. First, I tested 30 grams of the 75-15-10, +20 mesh. I got a flight time of 8.3 seconds. Cool, a good result right off the hop! I just had to see what would happen with the 70-20-10, so I tested it next. Right away I was impressed by the much louder bang. The flight time was 9.8 seconds!

Obviously, I had to dial back the amount to get the 7.5 second flight time Ned specified. I did so incrementally. The final amount was 14 grams. Yes, you read that right. Half an ounce of screen-mixed powder made with crappy charcoal got 'er dun! Actually, it more than got 'er dun. The times of 3 consecutive tests were 7.9 sec, 8.5 sec, and 7.7 sec, with an average flight time of 8 seconds.

As we can see from Ned's baseball testing chart, my screen-mixed powder beat out every milled powder test on the chart, save one. Wow, that's huge, IMHO.

As I said in the beginning, I'm not here to claim the prize. My method does not use commercial airfloat charcoal, which was one of Ned's requirements. I still win though, because I get to brag about my supermilled charcoal yet again But there's a lot of stuff for the winner (and everybody else that's interested) to consider here. I do have a few final thoughts on this.

I think a major factor in my excellent results (besides the supermilling;) is the use of hot water, and the amount used. The rapid crystallization of the potassium nitrate guarantees small crystals. Also, the presence of dextrin may form a colloidal suspension that prevents the growth of larger crystals. I could be totally out in left field on that one, but they use dextrinated solutions when producing lead azide by double displacement to prevent the growth of larger unstable crystals. Either way, I got to use important-sounding words. If cold water were used, much more of it would be needed. The drying time would be greatly increased as a result, which could form larger crystals. Everybody seems to agree that black powder that is dried faster makes better powder.

Altering the black powder formula made a huge difference. It's probable that I didn't pick the ideal ratios right off the bat, which would leave room for further improvement. I would highly recommend that folks read Ken and Richard's articles on black powder in AFN.

I hope this helps the winner, whoever he or she is. Somebody's gonna take Nedski for 40 bucks, I know it

"Black powder is mixed thoroughly, so as to fool the ingredients into thinking they are a compound." Anon

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I have no doubt that excellent lift could be made using ERC charcoal instead of mesquite, milling separately, and screen-granulating using the hot water method. I'd go back to 75-15-10 though. Since writing up the above, I've switched to using CMC as the binder for screen-granulating. It doesn't slow the burn as much as dextrin does.

[Steigede]

Wow. Excellent detailed write up! Thank you!

[dlking59]

Very well done and very informative. I really enjoyed your write-up. Thanks.

[SeaMonkey]

JustVisiting,

 

Agreed, very informative indeed and answers some questions.

 

I've always wondered why the Hardwood Charcoals which have a higher

Potassium Carbonate content than those most commonly used for Black

Powder were thought to be such poor performers.

 

Since Potassium Carbonate is the "magic" ingredient in Yellow Powder which

is several times faster than Black Powder, why wouldn't the higher Potassium

Carbonate in the Hard Charcoals have the same effect in Black Powder?

 

I believe your tests have shown that in fact it may when used in a higher proportion

than the more popular charcoals in the Black Powder recipe and also when it is

adequately ground to a very fine particle size.

 

Do the Hard Charcoals actually burn "hotter" as many believe? I've often wondered

about that too.

 

Your particular variant of the Wet Mix method using the small amount of very hot

water is especially interesting. Have you tried a slightly higher percentage of

Dextrin at any time?

Edited July 23, 2020 by SeaMonkey

[Arthur]

To test that hypothesis someone has to make batches of powder with each charcoal and adjust the mill process to get the optimum product from each charcoal.. There is no way that a hard charcoal is going to work it's best using mill times for balsa, vine or willow charcoals.

[kaotch]

@ justvisiting

 

David where did you post this article on FW, can't find it?

[justvisiting]

SeaMonkey, I tried the hot water method to coax better performance out of 'sub-par' charcoals. That, super-milling the charcoal, and increasing the charcoal content were helpful in my quest to make acceptable lift. Later, in an effort to win a contest, I had to use commercial airfloat charcoal 'as is' (with no milling of the charcoal). I used the same hot water method. The hardness of the grains with 2% dextrin was poor. Increasing the dextrin to 3% caused an unacceptable reduction in burn speed. In the end, I settled on 3% CMC as the binder, and used a cheese grater to granulate the powder. The thread documenting the experiments is called 'BP Differences and Characteristics'. It's in the Black Powder forum on FW.

I wonder what would happen if yellow powder was pressed up as a rocket. My guess is that it would be nearly impossible to light, and if it did, the motor would CATO when it got too hot. The way I understand it, yellow powder is very dangerous to make. I've never really thought about the actual chemistry of charcoal, to be frank. I couldn't comment on it with any certainty.

[SeaMonkey]

Just Visiting,

 

I had to chuckle when I read that you used a Cheese Grater to

granulate your powder. I thought maybe I was the only one who

did it that way.

 

First I ram it the old fashioned way it into a damp cylindrical "puck"

then grate it to size.

 

Your use of CarboxyMethylCellulose as a binder is interesting as

well. I'm about to try some Food Thickener which is a mix of

Modified Food Starch and MaltoDextrin since I have some on

hand. Just to see how it compares to home-made Dextrin.

Edited July 24, 2020 by SeaMonkey