My homemade black powder

[DoubleBuck]

HWooldridge;
The Waltham Abbey book also talks about their 76-14-10 powder. And it mentions someone, I think, in France, who was making a sporting powder of 78-14-8. Almar tested 76-14-10 Brown Black Willow powder and had excellent results with it. And, I think we both tested some 78-14-8, and speaking for myself, and I think him as well, haha; we neither one had that great of results from it.
On your note keeping comment, I was going to do it from the start and thought I would just go back and skim through it and pick up the parts I wanted to note. So, now I'm on the 40 page pernambuco file, and haven't wrote down a single note and already am regretting it. I've got the pen at the ready now and will take a minute or two hours researching all I've already read. haha

TrapperJack;
I think the reason for the 10% water in the powder you mention, was because of the friction of the shearing action, of their 8 ton? wheel mills. They also said in dry times, they sometimes added more, but milled it to a uniform moisture content, on the finished 'cake'. Depending on relative humidity, I think their cake was dried to about 4%.
In my opinion, if you get more than a slight 'haze' of moisture on your press backing plate, it's too much. At a very low moisture percentage, the nitrate begins to crystalize instead of staying incorporated, leaving hot spots and cold spots in the powder.
More moisture percentage tends to soften grains in the drying process, reducing some density which was pressed into the pucks. Their incorporation methods with the wheel mills still added some density to their meal, compared to ours being dry ball milled. That is why, I believe, they could compress it to a 35-40% reduction in volume and get their target density. VettePilot and I have discussed a couple of times, of putting fresh pressed pucks into a vacuum chamber and dry them, to reduce the effect of drying, on finished density.

[Trapper-Jack]

On page 12 of the Waltham Abbey book there is a list of the various proportions used by different countries. Most of the sporting powders list the higher76-78% potassium nitrate. For the most part the 10% sulfur is the same. The charcoal is varied depending on the percentage of potassium nitrate.
I've wondered for a while if the percentage of potassium nitrate is dependent on the amount of oxidizer needed by the charcoal for optimum performance.

[DoubleBuck]

I think you are exactly right. The better the charcoal, the higher amount of nitrate seems to be the answer. And cut it back on lesser charcoal. Just like 100 octane gasoline needs more air than 87 octane.

[HWooldridge]

I think you are exactly right. The better the charcoal, the higher amount of nitrate seems to be the answer. And cut it back on lesser charcoal. Just like 100 octane gasoline needs more air than 87 octane.

Good analogy and makes perfect sense to me.

[FrankJD]

I have read many of the articles and a few things that stand out to me is the moisture during the mixing. The swiss booklet says they will use up to 10% moisture during the wheel milling. (Page 15) Most of what I've read here is about dry milling in a ball mill but that is about the only option without a large investment. It may be comparing apples to oranges but I'm continually thinking about the moisture during the pressing. Normally I use 4.8% on newly balled powder, 4.5% when reprocessing the fines from previously balled powder. If I go higher than that I'll get excess bleeding of water (and I'm sure a portion of the potassium nitrate) out the bottom of my die using a 20 ton jack. Page 19 describes their roller press where the powder is compressed into a cake that is about .5 to 1 cm thick. Page 20 states that the powder from the wheel mill, being low density, is compressed 35 to 40% reduction in volume. The densification and consolidation of the powder doesn't require a great deal of pressure for a period of time as with a plate press but depends on the loss of moisture through evaporation to complete the mechanical strength in the grains. I'm sure I'm compressing my green powder way more than the 35 to 40%. What I've been doing seems to have been working, but would more moisture and less compression work better? I'm trying to wrap my mind around this new information and comprehend how it would improve what I'm already doing.

The dry ball milling of the key 3 ingredients to create meal powder is pretty straight forward.

Adding moisture to the green powder is more subjective - how does one know what's the right amount of water to add? What's too little, what's too much?

[Trapper-Jack]

I think you are exactly right. The better the charcoal, the higher amount of nitrate seems to be the answer. And cut it back on lesser charcoal. Just like 100 octane gasoline needs more air than 87 octane.

I keep thinking about adjusting a carburetor. Too lean and it doesn't have the power it is potentially capable of and too rich it'll choke and puke and emit lots of black smoke. When you get the air/fuel mixture right, everything smooths right out.

[Brimstone]

I keep thinking about adjusting a carburetor. Too lean and it doesn't have the power it is potentially capable of and too rich it'll choke and puke and emit lots of black smoke. When you get the air/fuel mixture right, everything smooths right out.

Precisely. One must consider the negatives of a lean ratio such as extreme heat. Think plasma cutter.
Super lean powder will very very quickly gut nipples and touch hole liners. I experienced this first hand. I don't make lean ratio powder anymore.

Too rich and you clog nipples and touch hole liners as well as the bore.

One more thing to consider. As Knight mentioned in his Swiss book, wet burning gunpowder retains more fouling as that fouling isn't blown out of the bore as it would were it dry.
I experience this on the regular as my entire focus is wet burning powder and blow tube soft fouling.

So if you guys cook your char at low temperature, use a good ratio and find you have a touch more fouling, it probably isn't because you did something wrong.

[DoubleBuck]

The dry ball milling of the key 3 ingredients to create meal powder is pretty straight forward.

Adding moisture to the green powder is more subjective - how does one know what's the right amount of water to add? What's too little, what's too much?

Frank, if you add too little moisture to your meal, when you press a puck, it will usually just fall back to meal, when removed from the die. They just crumble very easy. Too much moisture, and it will bleed out of the meal, in droplets of water squeezed from the meal. When too much moisture is present in the meal, it starts to dissolve nitrate, and will leach it from your meal, taking it's oxidizing power with it.
If your meal is completely dry, I have read that 3-5% is the range and that 4% moisture is optimum. I start with 4% and press a single puck. If the backing plate of my press has barely a trace or haze of moisture, I consider it near perfect. If it squeezes out a drop of water, I cut it way back on the next one. When I find the right percentage, I add that to the whole batch and stir it in completely until it is all uniform in moisture content. Some guys run it through a screen, to disperse the moisture equally.

[HamGunner]

The dry ball milling of the key 3 ingredients to create meal powder is pretty straight forward.

Adding moisture to the green powder is more subjective - how does one know what's the right amount of water to add? What's too little, what's too much?

I do not know exactly what the perfect total amount of moisture should be, but if not enough moisture is introduced the pucks will not be hard and will easily crumble. Those surely will not have a good ending density. If you get a trickle of moisture coming out of the bottom of the compression die, it certainly is an indication that you introduced a smidgen too much moisture into the green meal.

I use the spray bottle method to moisten up the green meal just prior to compression. I think either Lags or Almar suggested this method to more evenly moisten the meal without getting too early clumping. I spray about two or three sprays of water onto my meal that I have in a large plastic bowl and using vinyl gloves, mix well before adding a couple more sprays. I normally do at least 1 lb. of meal at a time so I think I likely will end up with 8-10 sprays of water before the meal starts to form a clump in my clinched fist. Once it is mixed really well, I squeeze a handful to see if it will stay clumped together. That indicates to me that I have enough moisture.

If I am not pressed for time, I like to seal the moistened meal and allow it to set for a few hours before I compress into pucks. I think this helps to incorporate the moisture more evenly into the meal. I have rushed this procedure and likely did not mix the moisture in well enough, and I ended up with light specks showing up on the compressed pucks. This surely degraded the final average density of the powder.

Edit: DoubleBuck beat me to the draw. Must be a faster typer. Anyway, I also like to see a slightly dampened spot below the compression die when I pick it up to remove the pucks. Seems to indicate to me that I have enough moisture.

[LAGS]

If the bottom of the compressed Puck is just a little wet and not Flowing off I think your moisture content is correct.
That is in my opinion.
I base that on doing construction and having to compress the dirt to build on.
We add enough water to the dirt to make it 2% more than the optimum moisture of the blend of soil.
When compressed , it looks damp , but not Wet.
But hay , that is dirt.
Dirt has so many more different chemicals that you have to test to determine what your 2% over optimum moisture will be.

[DoubleBuck]

Ham;
I do the same thing with covering the meal in a tupper ware type container and let it set awhile and stir it a few times, to equalize. I've had the best luck by weighing the meal and using a 1 or 3 CC syringe to measure the water. I think if you have a good eye, the mister may work better, as the droplets of water are so much smaller. Not sure which is best.

[LAGS]

I mix my stuff in a bowl.
Then after it sits for a bit.
I press it thru a screen twice to get it mixed evenly.
If water shows when screening , I just let it sit a little longer.
Then press the screen mixed stuff.

[HamGunner]

Well, a report on the Grapevine charcoal.

I ground it in a small hand meat grinder and then milled it for 2 hours and screened it through a 40 mesh screen. Done an ash test, 2 times. Both tests came out close to 7.5 % ash. On top of the high ash content, the charcoal took a good bit more heat to reduce to ash than my Black Willow, which I tested again along with the grapevine charcoal and using the same methods.

My Black Willow comes out closer to 2.5 % ash and readily burns up into ash. Guess I will not bother making any BP with the Grapevine wood. I am sure it would work and burn decently enough, but probably not nearly as fast and certainly not nearly as clean as my top two so far, which are Black Willow and Sassafras.

I will just wait another month or so until the Sassafras starts to bud out really well and cut me a nice bundle of that to debark and stock away to use after it seasons out. In the meantime, I have plenty of BP stocked up and a bit of seasoned and split up Black Willow if I should decide I just can not wait to play around making another batch of BP.

I also have a fair amount of debarked and seasoned Carolina Buckthorn (Frangula Caroliniana) that I may char again just to test it another time. Previous testing showed it a bit slow, but that was before my charring as well as other methods were more refined.

Edit: Is it possible that I over cooked my Grapevine charcoal in my new method using a pressure cooker pan, which caused more weight in ash? I would think that the ash content would still be about the same, but perhaps someone can offer an opinion.

[HWooldridge]

Ham,

FWIW, my grapevine charcoal burns cleanly but it hasn’t proven to generate as much velocity as my Goex control sample. I didn’t test the ash content but did cook it on the low end of the range and I had some brown charcoal mixed in. The original vine wood was also well seasoned and quite dry.

HW

[dtknowles]

My powder that I was calling 2f and 3f are not as close to the Goex powders I have as I thought.

So my powders are label wrong and should be one f graduation courser. what I labeled 3f looks more like Goex 2f, etc.



my meal weighed 24.9 gr.
my fines weighed 27.9 gr.
my was 4f should be 3f weighed 38.3 gr.
my was 3f should be 2f weighed 40.2 gr.
my was 2f should be 1.5 or 1f weighed 42.1 gr.
Goex 3f weighed 48.8 gr.
Goex 2f weighed 46.8 gr.

I also screened or CIA'd or whatever some meal. This is what I got.

CIA 1.5f weighed 37.2
CIA 2f weighed 36.5
CIA 3f weighed 36.2

I don't really understand why different granulations of the same powder have different densities, I guess they just settle differently. The courser stuff has higher density but you can't compress them as much.

Tim

[DoubleBuck]

Ham;
Edit: Is it possible that I over cooked my Grapevine charcoal in my new method using a pressure cooker pan, which caused more weight in ash? I would think that the ash content would still be about the same, but perhaps someone can offer an opinion.

The experience I had with the Mimosa I tested awhile back, it had a higher tested ash content when it was fresh cut wood, than did the charcoal. I had trouble wrapping my head around that. Never did, actually. I'm thinking that if you have more 'brown' in it, the same weight of a test of charcoal should show a lower percentage of ash, because there are more volatiles to burn off, from the original sample. Over cooked would seem to me to show a higher ash content because there would be less volatiles to burn off from the original sample.
You might try taking a small sample of your grape vine and burn it up and see if it gets close to the same ash content as your charcoal. Mine did not and I can't explain why. The two were pretty close but the twig showed a higher content than the charcoal did.

[HamGunner]

Lesson learned I guess.

Well, this vine wood was quite green. In fact, it was actually a green color inside. No doubt, a green wood will char and act differently than a seasoned wood and it may have been over cooked just a bit even though my temperature gauge did not show it. This wood certainly is not acting like it is wanting to readily burn like most of my charcoal.

When this wood was finished charring, I opened the lid and dumped the charred wood into a metal container that I could seal, because the gasket on the pressure cooker was burnt to a crisp and would likely allow air into the hot wood once the exhaust of hot gases had stopped.

I did notice that there were very few sparks as the hot wood suddenly got exposed to air when transferring to the air tight metal container. I normally see lots of sparks if the hot wood is exposed to air as the wood acts like it wants to flair into flames with the sudden exposure to oxygen. When this charred wood did not aggressively spark, I wondered about that at the time.

I will stick to seasoned wood and perhaps limit my temperature gauge reading to closer to 500 degrees to prevent over charring as the end of the probe is not long enough to actually touch any wood inside the pressure pan. I may have to actually stick a piece of wood onto the probe for a more accurate reading.

[DoubleBuck]

dtknowles;
"I don't really understand why different granulations of the same powder have different densities, I guess they just settle differently. The courser stuff has higher density but you can't compress them as much."
I think you nailed it. All of your weights make sense to me, except for the Goex samples. All your sample weights coincide with my experience. The smaller the grain, the lighter the weight of a given volume. But your Goex weights are opposite. Are you sure you didn't transpose the 2f for 3f and visa versa? I would have expected the Goex 2f to be heavier than the 3f, like all your other weights. Edit to say, IF the Goex 2f and 3f are the same density. They may or may not be and that would or could make the difference. If it is all the same density in their presses, then I would expect a given volume of 2f to weigh more than the 3f.

[HWooldridge]

dtknowles;
"I don't really understand why different granulations of the same powder have different densities, I guess they just settle differently. The courser stuff has higher density but you can't compress them as much."
I think you nailed it. All of your weights make sense to me, except for the Goex samples. All your sample weights coincide with my experience. The smaller the grain, the lighter the weight of a given volume. But your Goex weights are opposite. Are you sure you didn't transpose the 2f for 3f and visa versa? I would have expected the Goex 2f to be heavier than the 3f, like all your other weights.

Wouldn’t 3F be denser due to smaller grain size, resulting in less air space? Based on the same volume, I’d assume larger grains equal lighter charges, all else being equal.

[DoubleBuck]

HWooldridge;
The best way I can explain it is if you take a WEIGHED block of granite (or our puck) and start breaking it up, it gains more and more volume, as the rocks get smaller and smaller. Sand will be the greatest volume of them all. The grains of sand will have the same density as the block, but the volume will have gained at least times two, if not three.
Just as a comparison, now cut an equal WEIGHT block of sandstone and do the same thing, and the volume of the sand will not gain as much, in percentage of volume, because the DENSITY is much lighter. The block of Sandstone will have more volume than the block of granite, to begin with. To get sand from granite, it takes thousands of strikes, but to get sand from sandstone, it takes hundreds. Which will have the most volume? The Sandstone. it has the same size sand, but it has less density and weighs less.
I just came up with another comparison, which took a minute to find. 1 ounce of whole wheat berries has a volume of 2.49 tablespoons. While 1 ounce of whole wheat flour has a volume of 3.13 tablespoons. Every grain smaller than the original block, or berry, has air around it, and the smaller the grain; the greater the air space, and the greater the volumetric surface area.
There's the difference in the density pressed into our powder. The density of our pucks react the exact same way. The greater the density, the heavier a given volume will weigh.
So a light density powder with small grains (like screened) will have a lot of volume and be really fast, in linear burn rate; where a high density powder with the same size grains, will be slower. It has a lower volumetric surface area.
Yet, a high density powder, with smaller grains, with a slower linear burn rate; can produce higher velocities, as well. Because the grains have density, but also have a lot of volumetric surface area. It burns slower and more efficiently, and generates a longer pressure curve.
Also, powder with lighter density and larger grain size, can ALSO get greater velocity AND tend to have more accuracy. That was the theory on Waltham Abbey and the 1853 Enfield powder they perfected. Light density (1.5+) and larger grain <12, >20 mesh. Light density and less volumetric surface area,(and a totitally different charcoal). Longer pressure curve.
I believe that is part or maybe all of the reason, small grain powder burns faster than larger grain powder. The grains have more access to the oxidizer, because they have more volumetric surface area. To the point of diminishing returns. And, I ain't going there.
The formula is kind of like the octane rating of your charcoal times the availability of oxidizer times the proper Sulfated temperature control, divided by the grain size times the density of the grain. And, the unlimited combinations by which they can be applied.
Bottom line: smaller grain size equals more volume. Higher density equals less volume. I may be wrong, too. I was one time, but it was a long time ago, and I never have admitted it. haha