My homemade black powder

[almar]

That extra bit of ball milling did some good, Just a few sprays of distilled water in the mix and a 3500 psi pressure on the dies for 1 hour now gives a powder that is exactly 30 grains of weight for 30 grains of volume just like the commercial powder. That previous batch with a very high fps test must have been a fluke that one time because I was not able to reproduce it.

This newest batch gave the following velocity results contrasted with the swiss:

25 grains volume fff, 220gr Johnson and dow
1-676 fps
2-669 fps
3-656 fps
4-633 fps
5-696 fps
average 666 fps, stdev 23.44 fps

swiss fffg 25 gr vol, 220 gr Johnson and dow
1-710 fps
2-647 fps
3-681 fps
4-774 fps
5-703 fps

average 703 fps, stdev 46.66 fps

This newer version of the powder is not graphited or polished, I like the results very much and the fouling is similar to commercial powder, it is not bad at all. The could be some fine tuning with controlling the heat when making the charcoal but it think that this powder is very good. I will try some more black willow powder eventually because it is free and very available to me. Another thing to note is that I reworked the forcing cone to 11 degrees since the swiss test so its not a perfect bench mark anymore, pressures may have dropped and velocity as well, but I doubt that it would be very significant.


By the way, the pucks are 1.92 to 2.00 g/cc out of the press. And the problems ive been having with the lower density of fffg vs ffg is the fact that I did not screen it well enough. The fffg I screened yesterday was 24gr weight to 30 vol and my ffg was 30 for 30. I screened the fffg again this morning dry and the density increased to 30 for 30 like the ffg. I used a large paint brush to move the powder on the screen, this seems to be more effective.

[almar]

given that I changed the pistol slightly and that my loading technique changed a bit since I last test the swiss, I tested the swiss again with 25 gr and a 220 gr J&D and it gave me this:
1-764 fps
2-755 fps
3-755 fps
4-758 fps
5-791 fps

average 764.6 fps stdev 15.21 fps

There is no doubt that swiss is king here and wonder what they do with the charcoal and if they add more than just the basic three components to the mix.

Regardless, as long as the movement is forward all is good, part of the pleasure is the process. I still like the last batch I made, it's much better than the first one and gives good results.

[SeaMonkey]

The Swiss have developed a unique method to assure that the Charcoal they produce for their Black Powder has the qualities they desire.

Extract from the Swiss Black Powder Booklet

The Swiss powder plant imports Alder Buckthorn wood from Slovenia where it is cut and harvested in late winter just after
the ground has thawed and the sap begins to rise in the trees. It is at this time of year when the bark is most easily removed
by stripping with a sharp knife.

The late winter harvesting of both Alder Buckthorn and Black Alder provides an additional income for small farmers and land
owners at a time of the year when there is little else to occupy their time.

The bark on Alder Buckthorn and Black Alder is rather thin and soft so while saturated with the freshly risen sap it is easily
peeled away from the wood using a sharp knife. When freshly cut, the wood will contain about 20 to 25% water based on
weight of wood. When cut and placed under roof, this water content will drop considerably in a period of 2 to 3 weeks.
Once the wood has been cut, peeled and partially dried it is ready for shipment.

When the Alder Buckthorn wood arrives at the Swiss powder plant the shipment is stacked in the wood storage and aging
shed. A sign is placed on the wood to denote the type of wood and the year that it was received into the plant.

The word "Bourdaine" is the French name for the tree we call Alder Buckthorn
or Glossy Buckthorn Alder. The wood is aged for 3 years prior to being used to make charcoal in the plant.

An interesting note in this wood topic. The Alder Buckthorn is cut in late winter just after the sap rose in the tree with the
thawing of the ground. The sap at that time of year being rich in sugar which the tree had stored in its root system. This
sugar acting as food for the tree while it sets out flowers and develops leaves to the point where they would produce the
sugar the tree needs for growth. This sugar remains in the wood after it has dried. The finished charcoal, in addition to
having carbonized cellulose would also contain some caramelized sugar. Simple experiments have shown that this inclusion
of caramelized sugar is of benefit in the charcoal in the finished powder.

Charring

When the temperature of the wood, within the cylinder, reaches about 280 degrees Centigrade the carbonization, or destructive
distillation, of the wood will begin. As carbonization proceeds, the chemical changes within the wood produce heat. The outside
heating is then reduced. If a desired charring temperature is to be maintained, the retort operator must balance the outside
heating against the heat produced by the wood itself during the charring process.

A controller used to maintain a specified temperature within the retort. The alder buckthorn charcoal used by the Swiss powder
plant requires very specific physical and chemical properties. This temperature controller is crucial to maintaining a specific
temperature range that will insure the desired properties in the finished charcoal.

Unfortunately, the precise temperatures required to complete their Charring Process are not revealed.

It is known, however, that the Swiss Charcoal is not "overcooked" and that it contains a high percentage of "volatiles."

[DoubleBuck]

Great information and cool read, SeaMonkey! My next charcoal, I'm going to try cooking slightly different and see if extra volatiles will help in my experiments. I bake my charcoal in an open controlled fire. I have always lit the escaping gas and observe it turning from somewhat blue, with pressure, to dull orange, before it goes out. I have always stopped, just before the fire went out. I'm going to try shutting it down, while there is still a good orange/yellow flame. That should leave a bit of volatiles, and not be quite 'brown char'. My best charcoal was cut in early spring, but don't know if it was the sap thing, or luck, or what. I have some wood that is two years old, that is bone dry, in my shop. I have always made my charcoal on green wood, but my next will be that dry wood. It was actually cut and debarked in mid summer. It's a long time to wait until Spring. haha If I can remember that long, I'll try cutting some again, when the sap is coming up. I'd like to see that Swiss operation.

[SeaMonkey]

The Swiss Black Powder Booklet is too large to attach here so I've uploaded it to the Internet Archive where you may download it here.

The description of the charring process continues in the booklet with more information on charring temperatures to completion.

[almar]

The Swiss Black Powder Booklet is too large to attach here so I've uploaded it to the Internet Archive where you may download it here.

The description of the charring process continues in the booklet with more information on charring temperatures to completion.

Oh wow! That's a great read !

Looks like they seal the wood in a tank without vents? To saturate the charcoal with the volatiles i wonder?

[DoubleBuck]

Oh wow! That's a great read !

Looks like they seal the wood in a tank without vents? To saturate the charcoal with the volatiles i wonder?

Almar, I had actually put in my comment, that I want to try making charcoal in a pressure cooker. I erased the comment, because I figured no one was interested and it was kind of changing the subject. But, that has interested me for a couple of years.
SeaMonkey, I just got the link, and will read that, over the next short time. Thank you!

[DoubleBuck]

SeaMonkey, that is an excellent read! Lots of good information there. I'll keep that for future reference. Thanks, again, for the link!

[almar]

I thought of that too but you need to bring it up to 600 deg F, the typical operating temperature of pressure cookers are boiling point or 212 deg. The seals and such would fail i believe. Even those pricey afghan type pressure cookers wouldn't make it.

[DoubleBuck]

I thought of that too but you need to bring it up to 600 deg F, the typical operating temperature of pressure cookers are boiling point or 212 deg. The seals and such would fail i believe. Even those pricey afghan type pressure cookers wouldn't make it.

Almar, at the bottom of page 10, it talks about a 'Stack Vent' on their charcoal cylinder. I'm not exactly sure what a stack vent is, but I'm assuming it must be a type of pressure relief valve, or something to limit exhaust gases. I hear you, on the rubber seals of a kitchen pressure cooker. I was thinking more of a commercial type, with a bolt on, or screw on lid, with an inner lip and an outer lip, with metal on metal seal. I just read a chart that shows 1,000 pound steam is 546.4° F. That is still 30°f below the low temp of the Swiss char. So, I'm thinking whatever a stack vent is would probably be pretty critical to know.
Some saw mills around here used to have a wood fired creosote vat, for making railroad ties. I think they have determined that creosote is bad, and have came up with pressure treating lumber, which replaces it. Don't know if ties are still creosote, or not. In the process, they used the excess heat, to kiln dry lumber. I have made charcoal with lots of creosote in it, and thought it was a bad thing and recooked the coal, to get rid of it. They seem to say it is a good thing. I guess a guy can go as deep as you can stand, on making charcoal. haha It has given me a few things to think about.

[almar]

You are correct about the depths to which one can take this in pursuit of perfection. Although it is a very interesting subject, there is a point where i will draw the line on investment. I seem to already have a satisfactory powder both for efficiency and consitency even without polishing. If i can find a way to control the char temperature and produce an even chacoal with available sources i think i will be satisfied. I already have a pid controlled powersource that i made for casting, proven useful for many more things btw, i can use that with my 1500w hot plate and molten lead around a sealed metal canister with a small vent at the top, like a paint can. The pressures in the can will be low (very much desired in a molten lead bath) but the charcoal will likely be better that what i used previously. I think i read about something similar done here. The thermocouple would be in the can, close to the edge to both monitor the input an eventual exothermic reaction from the charcoal. There wouldnt be too much lead because you dont want too much thermal inertia in case the exothermic reaction rises the temperature quicker than the pid can control. These are just a few thoughts for now. The booklet also mentioned different ingredient proportions that i find interesting.

[Linstrum]

Hey, you guys have progressed a long way! Doing good!

I started making black powder in 1965 using charcoal I made from fir lumber because I didn't have any black willow. I used it in a muzzle-loading 1-inch smooth-bore canon my dad machined from a 3-inch diameter bar of SAE 1045 carbon steel. It went “BOOM” pretty loud and would shoot a one-inch ball in one side and out the other of an old wrecked car, so my fir wood charcoal black powder was good enough for that. The black powder was simply made by milling the potassium nitrate separately from the charcoal and sulfur, mixing everything damp as a paste, screening, and then drying. I knew it wasn’t even close to commercial stuff, but it did what I wanted it to.

I'm a chemist, and when I got done with college in 1975, I used what I learned. I still didn't have any black willow, though, so I investigated everything I could lay my hands on where I lived in Southern California, from all the kinds of native trees and shrubs, plus ornamental plants and trees that had been imported from everywhere else. About the only thing I didn't try was poison oak. Right off, I found out all the bamboo and grass species I tried were pretty bad.

I found a few sources that seemed like good candidates, but when I burned the charcoal, there was often a lot of ash left behind. So, I started assaying my charcoal for how much of it would not burn.

I found one particular 6-foot tall straight-stemmed feathery plant called fennel (foeniculum vulgare), sometimes mistakenly called anise, native to Southern Europe and the Mediterranean, which smells like licorice. It is a nuisance weed that grows everywhere along the Southern California coast. It made what seemed like the ideal charcoal that was light and fluffy, which I could pulverize with just my fingertips. But at only ~84% combustible material, it had unacceptable amounts of ash that interfered with fast burn, plus left hard gun barrel residue. But I made a test batch of black powder with it anyway, by adjusting for its 16% ash content. See later on for the mathematics involved, it’s not hard to do.

Assay your charcoal. If you shoot, you have an accurate powder weighing balance, and that's the only piece of precision equipment you need. How to find ash content is a pretty simple procedure. You will need a steel tin can lid like from a large size soup can, a propane torch, a kitchen stove, and some of your charcoal that has been coarsely powdered. Outdoors, use the propane torch to heat the steel tin can lid red hot to burn off the protective coating, and then scrub and wash the lid to get it clean. Weigh out more or less 50 grains of powdered charcoal, and note its exact weight to a tenth grain. Put the powdered charcoal on the tin can lid and spread it around in an even layer, keeping it away from the edge of the lid. Set the tin can lid and charcoal on a kitchen stove burner at just enough heat so the lid is a dull red heat. The charcoal will ignite and glow red hot, and after a few minutes, carefully sweep the charcoal around with the side of a length of wire, like a straightened large-size paperclip. Keep sweeping the charcoal around every few minutes, being careful not to spill any off the side of the lid. After about twenty minutes, there should be just a light gray ash left. Turn the stove off, and when the lid is cool enough to pick up, brush all of the ash into the powder weighing balance pan and weigh it. As an example, if the charcoal sample originally weighed 47.2 grains, and after burning it off on the stove, the ash weighs 1.8 grains, then 1.8 divided by 47.2 equals 0.0381. Multiplying by 100 gives 3.81% ash. Round-off to 3.8%

I don't use charcoal with more than 4% ash.

One more thing I was investigating was how hot to roast wood. High carbon content charcoal that conducts electricity does not make the best black powder. Using a temperature sensor inside the wood roaster to keep the temperature from going too high should be done so the wood doesn't decompose too far. How hot and how long wood roasts is important, because the creosote from partially decomposed lignin, cellulose, and all the other carbohydrates related to cellulose, like sugar, are a major part of what makes the best black powder. When the wood gets heated too hot, the "good stuff" volatilizes and leaves hard carbon behind, so what is left is "dead burnt" charcoal.

In about 1804, Monsieur Éleuthère Irénée du Pont de Nemours became the master black gunpowder manufacturer in the United States, which was just four years after he arrived from France in 1800. He personally had the knowledge of both the art and chemistry needed for manufacturing black powder that he had learned in France. The art part were things like not having a thermometer to know how hot the wood was while it was roasting, instead being able to “read” the flame characteristics of the burning wood vapor coming out of the wood roasting retort. I would think that du Pont very quickly planted stands of European black willow in Delaware for making his black powder, although grapevine, along with our four related species of rather abundant North American cottonwoods have been very successfully used at one time or another. The Confederate States used Eastern Cottonwood for its black powder industry during the Civil War. Grapevine is still currently used. Cottonwood is still used in Mexico, especially by their fireworks industry.

The math used to compensate for ash content is straightforward. Using my fennel charcoal from above as an example, the math steps are as follows:

1. 16% ash means there is only 84% combustible material, 100% minus 16% ash leaves 84% combustible material.

2. Convert 84% to decimal form that is 0.84

3. Mathematically invert 0.84 by dividing 1 by 0.84 to find out how much more ash-contaminated charcoal to add to the black powder mix so it comes out at the correct amount of combustible material. 1 divided by 0.84 = 1.190476. Round-off to 1.19

4. The next step is to multiply the 15 parts charcoal by 1.19 to get 17.86 parts of ash-contaminated charcoal. Round-off 17.86 to 17.9 parts charcoal. So, the new black powder formula using fennel wood charcoal is 75 parts KNO3, 17.9 parts of ash-contaminated fennel charcoal, and 10 parts sulfur

In my replica .36 Navy Colt, my fennel black powder did okay, but nothing even close to the du Pont ffffg I purchased back in probably 1973. That's what 16% ash does in black powder charcoal, it makes "just okay" black powder. I never used fennel again for firearms, but black powder made with it does have its uses, like for making your own quick match for cannon touch holes. For just that one purpose, fennel black powder burns slower, but ignites easier and burns smooth and steady.

I never had any black willow, but I did have “Jim Bacon” and “Hass” varieties of avocado tree wood that are both fairly soft but tough woods. The avocado woods I used assayed between 3% and 4% ash, very much lower than 16%. One year aged avocado wood has been my go-to charcoal wood. To adjust for 4% ash, there is 96% combustible material in the charcoal. The mathematical inverse of 0.96 is about 1.0417, round off to 1.04, and then that multiplied by 15 parts charcoal comes out to 15.6 adjusted amount of avocado charcoal to use.

To test charcoal to see if it conducts electricity, I use an electrical circuit testing ohm meter set at 20,000 ohms to check sticks of charcoal. How far apart the test probe tips are, and how hard they are pushed against the charcoal, are all part of it. Make sure you aren't touching the circuit test probe tips because you conduct electricity, too. I don't remember what resistance readings I got, but if the readings are low, your charcoal was heated too hot and too long. Low readings indicate your charcoal is a good conductor of electricity, a bad thing for making good black powder. "Dead burnt" charcoal conducts electricity quite well, Thomas Edison used charcoal strips made from bamboo for his first commercially successful carbon filament light bulbs!

So, what I did to make the best black powder I could was find a wood that made light fluffy charcoal with less than 4% ash. I checked my charcoal to be sure I didn't heat it too hot by using an ohm meter to see that it did not conduct electricity. I compensated for the ash by increasing the weight of the charcoal in the black powder formula. As far as ash content goes just by itself, it causes two problems. It interferes with black powder burning efficiently, and it decreases the amount of available fuel.

I live in south central New Mexico now, where there are both Fremont and Narrow Leaf cottonwood everywhere. Both look promising from the minuscule amount of ash left from burning a sliver of the wood.

Assay your charcoal for ash content. Finding out that 1/6 of your charcoal is not charcoal may be a bit of an unwelcome surprise!

[henryinpanama]

"Assay charcoal for ash content, do not heat charcoal wood too hot"

Thanks for that very informative post.

[almar]

Thank you Linstrum for this very good post. I performed this test immediately after reading it and my charcoal has a 12.6% ash content. I most certainly can make a better charcoal than that. At the time charred it without thought to volatile content or measured application of heat.

In a way, this is good news since the path to a better performing charcoal is clear and mesurable.

[SeaMonkey]

Linstrum,

You have proved Scientifically what many have suspected but had no idea how to go about evaluating!

The analytical formulas you have provided give us an easy way to make adjustment to assure that our Black Powder contains enough inflammable material to perform its best.

Also, we now have an easy way to test our Charcoal to assure that, for firearms use, the Ash Content is as low as possible.

Many Thanks!

It would be interesting to know the Chemical Composition of the Ash.

[LAGS]

Thank you Linstrum.
I was concerned before on the ash ratio of my charcoal.
But never had a method to check it accurately.

[DoubleBuck]

Thanks for the great post, Lindstrum!

[Eddie2002]

Great post about ash content it totally opened up an unknown way to improve the process, I'm impressed with the simplicity and logic of it. I was wondering about testing the resistance of the carbon also so bear with me. If a known weight of carbon was compressed in a tube like a narrow piece of PVC pipe wouldn't it be possible to check the resistance by applying the meter to either end of the carbon plug? This might be a simple way to check if the charcoal was over cooked for those without a temperature controlled retort. A know weight of charcoal would be needed for a consistent test.

[almar]

I made some more charcoal from that plum wood today and tested it with the linstrum method described in his post.
the picture below shows the simple setup, the thermocouple was in a paint can with the charcoal and you can see the PID box next to the pot. The PID controller was simply used as a thermometer this time but with a hot plate (I seem to have misplaced mine) it can actually regulate the temperature automatically. The paint can is in a pot with about 30 lbs of lead, there are three 1/8 hole in the middle of the lid and the weight on top keeps the can from floating.



The previous batch I made was simply cooked hot as I could in the fire pit until there was no longer any pressurized steam exiting from the can. The resulting charcoal had an ash content over 12%. This new batch was kept right at 600deg +10/-10 for 6 hours and the resulting ash content is 0.78/30 = 2.6%. This is very promising. I wonder if I should use the swiss 78/10/12 ratio for the next batch.

[LAGS]

With your charcoal having a lower Ash Ratio then that may work.
But I would try it at the universal 75/15/10 ratio first , and see how much it improves you current powders.