Black Powder burning speed x charcoal

[jimjones]

Just out of curiosity, I met a person that does research on sugar cane charcoal (activated charcoal) and asked for some information. I will post some of the pictures he sent me:

 

Image generated using synchrotron light:

(difference between hardwood and softwood)

 

Images and video generated using x-ray tomography:

(sugar cane - the white part is the xylem channels and the rest are celulose, lignin and others)

 

(charcoal )

(charcoal )

 

The pores generated by activation do not appear in these photos. They are in the order of nano meters. The pores that we see in the photos are from the plant xylem.

 

 

[SharkWhisperer]

Nice pix. Clearly highlights the porous nature, at the macro and micro levels. It's clear from the macrostructures how extra milling to make components as fine as possible can "push" ingredients into the larger pores--many are much much larger than our nitrate and S, but you still need to get it in there physically. Filling the micropores (nanometer size range) related to the molecular structure (not plant morphology such as large xylem voids) probably depends more on solubilized nitrate entry during brief wetting. Of course the macrostructure of different woods, and their charcoals, vary tremendously across plant/tree species. Photos like these are very useful to help visualize the physical intricacies of charcoal in BP making. Cool pix!

 

Looking forward to your updated burn test results after optimizing milling!! (and extra drying)!

 

Perhaps instead of igniting a gram in a single rounded pile, try to get film of a longer BP burn along your angled iron bar? Perhaps 30 cm or so?

 

I don't know how much quantity you have left from your bag of eucalyptus charcoal, but if you are happy with it (it looks like you could be), it would be helpful for you to stockpile a reasonable quantity for several years work (a 15-pound bag=100 pounds of BP, which is a lot for hobbyists, but nothing for pros doing large shows or making huge shells).

 

I think it was JV that mentioned it before, but charcoal does absorb atmospheric water, as does KNO₃. This can affect you: 1) screw up your chem ratios a little bit due to sub-accurate weighing; 2) cause clumping while milling which is hard to overcome and can affect BP performance significantly. I oven dry my charcoal and nitrate separately and store with dessicant packets to avoid these problems completely. Generally speaking, even stored with dessicant, if I haven't used a batch of chems in the past month, i'll re-dry them in the oven before making BP. Is simple and not so time-consuming. Low heat for a few hours works fine, spread out on a baking pan or cookie sheet.

 

Looking good!

[Boophoenix]

Here’s some irony. In one of my meteor shells I built using a charcoal based meteor comp I monitored the weight as a dried it. After removing it from heat when it appeared to stop loosing weight it regained enough to measure in 15 to 30 minutes.

Some more charcoal pics from one of Sasse’s papers I believe it was. I don’t recall the source material if it was even listed though.

 

 

 

 

 

Edited February 11, 2020 by Boophoenix

[jimjones]

Boophoenix, nice pictures. You monitored the BP weight or the charcoal weight?

 

Today I finished testing the eucalyptus BP after different milling times. I didn`t granulate the BP to be able to do this test faster. I used the method I described in the first message of this post. Unfortunatelly, only after doing all the BP burning and video recording, that I realized that this method is not precise enough to define what is the optimal milling time for my mill setup.

My observations:

a) some times sparks jump forward in the BP trail and reduces the burning time considerably

b ) I still used marbles to mill the BP. I bought 13mm lead balls, I`m waiting for them to arrive.

c) after 24h of milling the BP was clumpy. It rained all the time, the humidity was very high, maybe it affected the BP.

d) I should have done 3 runs with each BP and taken the time average. It would be much more conclusive

e) The video with all the runs is attached bellow (I reduced its quality).

f) even though there is some randomness in the data, we can see that after 7 hours it seems that the gains are lower.

 

Results:

Edited February 12, 2020 by jimjones

[SharkWhisperer]

Yeah, JJ, it's hard to decipher best milling times from scattered single-point data, but it seems the trend is increased speed with more milling time. In smaller mills, I'd hit the wall--the point of diminishing returns in burn speed--after around 8-10 hours milling. If your BP begins clumping before then, probably your nitrate or charcoal has unwanted moisture in it. You can remove this by baking them separately for an hour at around 200-210F (around 100C). If you get clumps early on, even if you break the clumps apart or screen them back to powder, they will probably clump up again pretty quickly after you restart the milling. As long as your chems are dry (and nitrate/charcoal stored with a dessicant), external atmospheric humidity probably won't be a big issue. I mill well on rainy days. The moisture in the air of a sealed drum is not really enough to cause problems, at least in my experience.

 

What are your subjective observations regarding burn rate vs milling time. Does it seem to be burning faster after 8 hours milling versus 3 hours milling, for example?

[SeaMonkey]

KNO3 is very difficult to buy in Brazil. So I bought a fertilizer grade KNO3, you can see

its composition on the attached picture. Do you think I should try to purify this KNO3?

 

jimjones,

 

The NPK rating of the Potassium Nitrate in your photo is 13:02:44 while the rating

for pure Potassium Nitrate is 13:00:45 or 13:00:46. This means that your fertilizer

contains a small amount of a Phosphate, the type not specified. Since some

Phosphates are Flame Retardants it is possible that it does have a deleterious effect

on your using it for Black Powder.

 

Phosphates are added to fertilizers to promote root growth in plants mostly.

 

It might be possible to purify your Nitrate by recrystallization. Then you'd know

for certain whether the mix you have is less than ideal.

 

Richard Nakka's procedure for purifying fertilizer Potassium Nitrate.

 

Your test video is quite interesting to watch. After each burn how would you

describe the residue left in the trail? Does any of it appear to be like solidified

molten slag? Is there a lot of residue or very little?

Edited February 12, 2020 by SeaMonkey

[SharkWhisperer]

Good eye, Monkey.

 

Unless there are other more pure agricultural KNO₃ products available, he might just have to live with this limitation (hopefully minor). So far, he's been getting reasonable (and improving) burn rates using this and a commercial lump eucalyptus charcoal that many would not have guessed would give great results. His pre-optimization granulated powder burn video from the other day suggests his BP is approaching burn speeds that, while maybe not yet white-lightning fast, is still very useful for all but the hottest burn requirements (e.g., nozzleless rocket fuel)...

 

It might be difficult to crystallize the nitrate away from the unknown phosphates, possibly one of the potassium phosphates that are commonly used in fertilizers. Of the three potassium phosphates, all are soluble in water, dibasic and tribasic very much so, and monobasic a little less so. I don't know the temperature dependence of these phosphates regarding water solubility. If they are like KNO₃ (very soluble in hot water & sparingly soluble in cold water) then you'd just be recrystallizing them back out of solution together again when you put the saturated hot solution on ice. You'd need to look up the temperature/solubility relationship of the additive phosphate to determine this. JJ, is there an MSDS (material safety data sheet) available from the manufacturer online, or can you get this information by email/telephone?

 

Anyways, Nakka's Experimental Rocketry website has some useful information on it, particularly for the sugar rocketeers among us.

 

JJ's oxidizer clearly oxidizes charcoal and sulfur pretty effectively, so this nitrate source might be the best he has available. If so, it's not the end of the world, or your pyro career :=}

Edited February 12, 2020 by SharkWhisperer

[Boophoenix]

JJ, I monitored the overall weight of the meteor shell as each of the last couple of layers went on. If my memory serves correctly I used a C6 formula for the the meteor portion of the shell. It was my first attempt at a meteor shell. My second shell to ever make and first solo build. My first was a shell building class I attended I was lucky enough to get an invite to that was for Disney employees.

Another funny antidote of that project it would stop loosing weight in about 30 minutes as it had to be dried rather often. It seemed fairly easy to tell when it was dry or when it picked moisture back up using a 0.01g scale.

 

In case you are not familiar or others aren’t as they are not very popular here’s a photo of that shell. 3 inch ball shell rolled in C6 to be shot from a 4 inch mortar.

 

Just to add I don’t recall if it was mentioned when you switch off to lead hopefully it hardened lead and if you start having clumping issues it’s not a bad idea to dry the mill jar and media as well.

[SharkWhisperer]

Phoenix, cool shell. And messy. And prone to be hygroscopic from the exposed BP deriviative (C6) which will variably absorb water depending on the weather and storage conditions. This could result in variable peformance with the upward meteor burn. You could shoot them soon, or store them in an airtight container with a dessicant to keep moisture levels more uniform, though a tiny bit of water might not have a great impact on the end results.

 

It might be cool to make a sister shell, but coat it with a final layer of a BP slurry in 10% NC lacquer. To provide some waterproofing and make the surface less delicate to handling. It would be interesting to see if this worked, and if it affected your shell's functionality and burn characteristics. Might be fun if you have time and materials. Just a thought.

 

Regarding lead media, yes, antimony-hardened lead is more durable (and expensive). But many, myself included, use straight lead balls, which also work great. Their downfall is that they will lose an incremental mass after repeated use--so will the hardened lead, but at a slower rate. The soft lead might impart a grey tinge to your white components like KNO3 during milling which is minor lead contamination. I have never noticed an impact on the function of the final BP. And physical lead exposure is probably not as high as one might think, and for that reason is not really a toxicity concern. There was a thread on here where this was discussed (I forget the author), and he performed theoretical calculations on how much lead is released, and human exposure when it is burned in typical pyro use; both values were low enough not to suggest any real health concerns are likely to occur. I have no problem using pure lead musket balls (.50 caliber, 12.7 mm) and they work very well--much better than marbles I'd used in the past. And faster. I would consider the added expense of buying hardened lead when I eventually need more milling media, but it is low on my priority list. I buy from a sporting goods outlet, but there are many online sources, at predictably variable prices. Although shipping heavy lead to Brasil would probably cost more than the media itself cost, it could probably be located in Brasil. There are multiple sources for hardened lead balls here in the US, with an equally wide variety of costs for the same product, so it requires shopping around.

 

I've never had a BP clumping issue related to using wet milling media (easy to dry off completely; lead is absolutely non-hygroscopic), and my millinig jars don't have a lining that would promote moisture accumulation, so I've never worried about those parameters. All of my past clumping issues have been clearly attributed to moist chems (undetectable by touch, only by accurate weighing and by clumping that effectively stops the milling process). Even clumped BP can be rescued if you sieve it to a fine powder, put it in the sun or a dryer box for a bit to drive out moisture, and then return it to the jar and restart the milling. Or you could just use it for slow-burn applications instead, although it would not be well standardized.

 

Are you bottom- or top-fusiing those C6 meteor shells? I'm guessing you're just lighting lift from below with Visco through a hole... You use a lift cup or bag, or just loose powder at the bottom of the mortar? Love to see pix of it in action!

[Boophoenix]

That picture was taken while still damp from a rolling session hence the gloves on. I’m not sure the comp is any more prone to taking up moisture than BP to any major degree. That’s above my pay grade as I’m just a simple hobby guy and investigator of the art to learn more. Actually I recon the higher charcoal content could make it a little more prone though. I found it interesting I could measure it that soon. I’ve seen a few things written about BP moisture contents, but none that stands out in my mind which is somewhat normal as I don’t retain much of what I read.

That one ( first ) was just lifted with BP in the mortar and bottom fused. The next one I shot was bagged with a lift bag with quick match leader to the bottom. They aren’t all that different than any other shell once finished. Bagged seems a good way to prep them to fire quickly though. I’m still learning things about them.

Neither has been a very good break. The first I figured out after firing the shell my stars didn’t bind well so I assume they shattered on break along with confinement was poor too. Which I think explains the very unremarkable break the shell had. The second was a rush tinkering job as well and strangely enough it shattered some on lift. To my surprise it still functioned somewhat as it should I think even considering some things were changed to address the confinement issues of the first shell.

 

I don’t have a good test site so building lifted items is limited to rare occasions that I have a place to tinker with them. Someday maybe I’ll learn to take notes and not try to rely on my memory when tinkering with projects so far apart instead of threads were I’ve discussed issues that arose if they came up.

I’m by no means an accomplished builder so they are not anything spectacular just attempts to get things to work and learn from.

 

The first shell ( poor break )

 

https://youtu.be/uWbOGRkBLE8

 

The second shell. The break timing was off a hair I think possibly from the shell shattering a little on lift noticeable by the mine effect at the bottom of the screen as the video starts.

 

https://youtu.be/iGzjAXXEFBs

 

 

 

 

[SharkWhisperer]

A detailed notebook is invaluable in helping to make improvements and not repeat same "mistakes" (for lack of a better word). Especially when those videos were shot 3 years apart.

 

Second shell looked pretty nice--you can pretend the mine effect was intentional, hah ha. Which star comp and burst did you use?

 

If I relied on memory, especially with more complex and/or experimental compositions, I'd be constantly reinventing the pyro wheel. A notebook (and using it) is super helpful.

 

I'd think that exposed C6 would be more prone to atmospheric water flux than comps sealed within multiple layers of kraft (or plastic hemis).

[jimjones]

jimjones,

 

The NPK rating of the Potassium Nitrate in your photo is 13:02:44 while the rating

for pure Potassium Nitrate is 13:00:45 or 13:00:46. This means that your fertilizer

contains a small amount of a Phosphate, the type not specified. Since some

Phosphates are Flame Retardants it is possible that it does have a deleterious effect

on your using it for Black Powder.

 

Phosphates are added to fertilizers to promote root growth in plants mostly.

 

It might be possible to purify your Nitrate by recrystallization. Then you'd know

for certain whether the mix you have is less than ideal.

 

Richard Nakka's procedure for purifying fertilizer Potassium Nitrate.

 

Your test video is quite interesting to watch. After each burn how would you

describe the residue left in the trail? Does any of it appear to be like solidified

molten slag? Is there a lot of residue or very little?

I think I found a better potassium nitrate for BP here in Brazil, its name is DRIPSOL® NKS. They say it is 12:00:45 with 1,2% of sulphur. I will also experiment with this one.

 

 

These tests from the video didn`t generate a lot of residue. And the residue was in the form of small black spheres. The iron became black, but if you pass your finger it is easy to remove this black dust. One thing I noticed is that this black residue dust feels oily. Do BP generate oil residues? But it maybe just my impression.

 

 

 

Yeah, JJ, it's hard to decipher best milling times from scattered single-point data, but it seems the trend is increased speed with more milling time. In smaller mills, I'd hit the wall--the point of diminishing returns in burn speed--after around 8-10 hours milling. If your BP begins clumping before then, probably your nitrate or charcoal has unwanted moisture in it. You can remove this by baking them separately for an hour at around 200-210F (around 100C). If you get clumps early on, even if you break the clumps apart or screen them back to powder, they will probably clump up again pretty quickly after you restart the milling. As long as your chems are dry (and nitrate/charcoal stored with a dessicant), external atmospheric humidity probably won't be a big issue. I mill well on rainy days. The moisture in the air of a sealed drum is not really enough to cause problems, at least in my experience.

 

What are your subjective observations regarding burn rate vs milling time. Does it seem to be burning faster after 8 hours milling versus 3 hours milling, for example?

For me it seemed that the last BPs I tested were hotter than the first ones, with less mill time. But the difference in speed I only noticed from the BP that I milled for 1h to the others. Anyway, the lead balls I bought should arrive this week, then I will be testing it again.

 

 

JJ, I monitored the overall weight of the meteor shell as each of the last couple of layers went on. If my memory serves correctly I used a C6 formula for the the meteor portion of the shell. It was my first attempt at a meteor shell. My second shell to ever make and first solo build. My first was a shell building class I attended I was lucky enough to get an invite to that was for Disney employees.

 

Another funny antidote of that project it would stop loosing weight in about 30 minutes as it had to be dried rather often. It seemed fairly easy to tell when it was dry or when it picked moisture back up using a 0.01g scale.

 

In case you are not familiar or others aren’t as they are not very popular here’s a photo of that shell. 3 inch ball shell rolled in C6 to be shot from a 4 inch mortar.

 

4ED143A9-1AC6-4702-885E-9C0585A8C27D.jpeg

 

Just to add I don’t recall if it was mentioned when you switch off to lead hopefully it hardened lead and if you start having clumping issues it’s not a bad idea to dry the mill jar and media as well.

interesting shell.

 

and, I don`t think the lead balls I bouhgt are hardened. They are for hunting. Is it going to be a big issue?

[SharkWhisperer]

and, I don`t think the lead balls I bouhgt are hardened. They are for hunting. Is it going to be a big issue?

Nope. They'll wear out a little faster than hardened lead and might turn your KNO₃ from pure white to slightly grey with long milling times, but neither is really a problem nor a safety issue. They'll perform much better than less-dense glass marbles, but be careful not to overload your mill and stress your motor too much, which is possible with some smaller mills. You want your mill jars filled halfway with milling media, not the 30% you use with glass marbles, but you can reduce this amount if it's overloading your mill motor.

[jimjones]

SW, what kind of milling jar you use? size and material? Is it similar to the jars used by other member here?

I use a plastic one, 1.7L, 13cm diameter. It seems to be good. The potassium nitrate is like salt, but after milling the powder is similar to flour.

 

Phoenix, cool shell. And messy. And prone to be hygroscopic from the exposed BP deriviative (C6) which will variably absorb water depending on the weather and storage conditions. This could result in variable peformance with the upward meteor burn. You could shoot them soon, or store them in an airtight container with a dessicant to keep moisture levels more uniform, though a tiny bit of water might not have a great impact on the end results.

 

It might be cool to make a sister shell, but coat it with a final layer of a BP slurry in 10% NC lacquer. To provide some waterproofing and make the surface less delicate to handling. It would be interesting to see if this worked, and if it affected your shell's functionality and burn characteristics. Might be fun if you have time and materials. Just a thought.

 

Regarding lead media, yes, antimony-hardened lead is more durable (and expensive). But many, myself included, use straight lead balls, which also work great. Their downfall is that they will lose an incremental mass after repeated use--so will the hardened lead, but at a slower rate. The soft lead might impart a grey tinge to your white components like KNO3 during milling which is minor lead contamination. I have never noticed an impact on the function of the final BP. And physical lead exposure is probably not as high as one might think, and for that reason is not really a toxicity concern. There was a thread on here where this was discussed (I forget the author), and he performed theoretical calculations on how much lead is released, and human exposure when it is burned in typical pyro use; both values were low enough not to suggest any real health concerns are likely to occur. I have no problem using pure lead musket balls (.50 caliber, 12.7 mm) and they work very well--much better than marbles I'd used in the past. And faster. I would consider the added expense of buying hardened lead when I eventually need more milling media, but it is low on my priority list. I buy from a sporting goods outlet, but there are many online sources, at predictably variable prices. Although shipping heavy lead to Brasil would probably cost more than the media itself cost, it could probably be located in Brasil. There are multiple sources for hardened lead balls here in the US, with an equally wide variety of costs for the same product, so it requires shopping around.

 

I've never had a BP clumping issue related to using wet milling media (easy to dry off completely; lead is absolutely non-hygroscopic), and my millinig jars don't have a lining that would promote moisture accumulation, so I've never worried about those parameters. All of my past clumping issues have been clearly attributed to moist chems (undetectable by touch, only by accurate weighing and by clumping that effectively stops the milling process). Even clumped BP can be rescued if you sieve it to a fine powder, put it in the sun or a dryer box for a bit to drive out moisture, and then return it to the jar and restart the milling. Or you could just use it for slow-burn applications instead, although it would not be well standardized.

 

Are you bottom- or top-fusiing those C6 meteor shells? I'm guessing you're just lighting lift from below with Visco through a hole... You use a lift cup or bag, or just loose powder at the bottom of the mortar? Love to see pix of it in action!

[jimjones]

Nope. They'll wear out a little faster than hardened lead and might turn your KNO₃ from pure white to slightly grey with long milling times, but neither is really a problem nor a safety issue. They'll perform much better than less-dense glass marbles, but be careful not to overload your mill and stress your motor too much, which is possible with some smaller mills. You want your mill jars filled halfway with milling media, not the 30% you use with glass marbles, but you can reduce this amount if it's overloading your mill motor.

my 1,7L jar, half filled with lead balls will be very heavy. I will check if it is not overloading the motor.

[SharkWhisperer]

JJ, for the size of the batches you're making, I'd just use a coffee grinder instead of milling my KNO₃!!! 10 seconds to dust instead of hours of waiting for the mill to do its job. Your charcoal would probably cause a mess in a coffee grinder, though, but a mill takes a long time. For charcoal, I usually don't premill. I fill up a gallon (4-liter) plastic bag halfway with charcoal chunks and beat it gently with my rocket ramming hammer (3-pound sand-filled orange plastic deadblow hammer from Harbor Freight) until it's "mostly" powdered. I let the milling do the rest (doesn't take long) in combination with my nitrate and sulfur (and dextrin/SGRS/red gum...if I remember). I've pre-ground/pre-pounded my chems, but usually don't bother spending time to actually mill them separately (sometimes with charcoal--I uses airfloat for other purposes than granulated BP; never with KNO₃--coffee grinder only).

 

My primary mill jar is almost identical to yours in diameter and capacity, made from PVC. I usually use it to make 300-400 g batches. But I also bust out the Harbor Freight 2-barrel hobbyist mill sometimes when I want to spin separate formulations at the same time, and can overload it towards 200g batches if using single barrel, though 100-150g is probably what most people use it for. Those small barrels are approx 4" inner diameter (10 cm) and rubber-coated. That little mill won't spin with both barrels half full of lead--too much for the motor, but will spin them both if you use lighter media like (gasp!) glass marbles.

[SharkWhisperer]

my 1,7L jar, half filled with lead balls will be very heavy. I will check if it is not overloading the motor.

If your motor won't spin, it's overloaded. If your motor gets hot to the touch, and cannot be sufficiently cooled down with a fan, it's overloaded. And risking damage. If so, you might need to reduce your lead media from the usual 50% volume and maybe mill a little longer.

[justvisiting]

I wouldn't use glass marbles because they are too light and have been known to cause accidents, one of which was reported on this forum. I'm surprised nobody has mentioned it. Also, milling charcoal by itself with soft lead media will add lead to your charcoal in amounts that can be measured in grams.

[SharkWhisperer]

I wouldn't use glass marbles because they are too light and have been known to cause accidents, one of which was reported on this forum. I'm surprised nobody has mentioned it. Also, milling charcoal by itself with soft lead media will add lead to your charcoal in amounts that can be measured in grams.

The possibility was alluded to, early on. That said, accidents have also happened with more "acceptable" milling media. Although I couldn't "recommend" it, I've milled over 100 batches of BP with marbles...lucky? Perhaps. Overblown danger? Perhaps. One incident, not definitively demonstrated to be directly related to using glass, is suggestive, but is anecdotal and is not proof. Stainless sparks too, potentially, and is used all the time.

 

And, without evidence, I call bullshit that you can measure "grams" of lead in batches of charcoal milled with soft lead media. Uhh, maybe in industrial sized batches, but not in typical amateur pyro-sized batches. Simple to determine by weighing your media before & after. I challenge you to prove your statement.

Edited February 12, 2020 by SharkWhisperer

[NeighborJ]

JV has already proven his claims. I thought you had no problem finding the info you are looking for using this forum? You're welcome to prove him correct again.

[SharkWhisperer]

JV has already proven his claims. I thought you had no problem finding the info you are looking for using this forum? You're welcome to prove him correct again.

Looked through various posts, and there is no consistency--some say they get significant media wear, some say no significant wear after months+ of soft-lead milling, which is my experience. Nobody has reported compromised BP quality of soft-lead milled BP, and in terms of toxicity, how much are you planning on eating or breathing in?

[NeighborJ]

JV is not just making claims. He has done the experiments and posted the conclusive results. Lead media does wear and that wear is measurable.

 

I continue to use hardened lead media and am undeterred by the amount of lead which contaminated my BP. The media I currently use is 6 years old and only now, am I able to start measuring a slight decrease in diameter. I do a lot of milling but direct comparisons cannot be made between my experiences and JV's. My media is much smaller than what he used, my media will not have the same impact wear as his.

 

Because of the myriad of possible things which can skew the results, every pyro needs to determine what matters most and what may not be relevant to his operation. The facts are out there and the choice lies squarely on the shoulders of the operator, not some guy you met on the internet.

 

All that being said, It needs to be reinforced that certain media will definitely cause problems for a pyro and marbles is definitely one of those medias.

[jimjones]

I did a rather revealing (and maybe dangerous) test.

I got the eucalyptus powder that was milled for 24h and did the same granulation proccess as before. But this time I put it inside a top-down grill (the heater is on top - similar to this one https://images.madeiramadeira.com.br/product/images/23906287-churrasqueira-eletrica-fischer-ranch-grill-3-espetos-220v-7896513316171-4_zoom-1500x1500.jpg )

 

The BP dried very fast and the granules are much harder than the ones that took a long time to dry.

 

I did the same trail test again. This time it was extremely fast and hot. I measured 0,4s to burn the 30cm trail... so 75 cm/s (30 in/s). The video with the test is attached.

 

Another test, burning it over a piece of paper (if you pause the video at the end you can see that there was almost no residue, but there was some ember of paper):

 

It seems a good BP. Now I have to find a way to dry my next batches fast, but in a safer manner.

 

btw, what are the rules of the tenis ball challenge? is the tenis ball method the best one to compare BPs?

Edited February 12, 2020 by jimjones

[NeighborJ]

That's a great success.

 

There are msny ways to dry BP. I try to make most of my powder seasonally when it is hot, sunny and dry. When this isn't an option I use a drying box fitted with screen racks, a fan and an external electric heater.

[SharkWhisperer]

Yes, amigo, build yourself a drying box. PLEASE. That open heating element is going to set a batch on fire one of these days and it will not be pleasant, particularly if you are doing this in your kitchen (yipes!).

 

As we exchanged, your BP was apparently not completely dry ("dry to the touch" means little). But overall this is fantastic news. Now find a way to do it safely.

 

It is easy to use an electric heater with a ceramic heating element and a fan to pump warm air wherever you want. Build a nice tiered wooden drying box, or, in a pinch, build a temporary cardboard box unit, which is simple to do. Just please, please, please stop drying it in an oven, electric or gas--that is definitely an accident waiting to happen!!!

 

Like Neighbor who lives in the US winter cold zone says, he dries outside in the summer sun and with a drying box in the winter. I do, too and it works great! It's summertime in your town, rain be damned.

 

Once granulated, store it with a few dessicant packets in a sealed container. Unlike nitrate and charcoal that you can reheat in the oven (safely) whenever you want and as many times as you want to if it's been sitting around, you really don't want to have to worry about drying your BP more than one time after granulation.

 

Great job and great success, but no BP in the oven!

 

Please.

 

I just watched your videos. You have made some badass BP!!! Congratulations!! But it worries me that I suspect you are doing not only your drying (cringe) but also your testing, indoors. Be careful.

Edited February 12, 2020 by SharkWhisperer