Saturday, October 29, 2016

Examining Black Powder Quality - I

In the last several weeks, we have taken a detailed look at the manufacturing process for black powder. In today's post, we will look at some of the procedures that were used in the 19th century to ensure black powder quality. The procedures used examined both the physical and chemical properties of black powder. In today's post. we will look at some of the physical properties that they would look for.

In places where good quality black powder was made, the powder was examined immediately after the blending process was completed. They would also periodically take small samples from powder stored in warehouses for analysis, to make sure that it was still usable.

The first thing they would do is give it a visual inspection. The color of good quality black powder should be a uniform dark gray (or slate) color. If the color has a blue tint or is very black, then this indicates that the powder has too much charcoal or contains too much moisture. Powders made of red charcoal (such as cocoa powder) should be of brownish-black color.

A sample of good quality black powder. Click on the image to enlarge.

After this, they would examine a small sample with their eyes or through a magnifying glass. Properly mixed powder should not show any difference in color even when crushed, nor should it be possible to feel sharp particles. A variety of colors indicates that the powder was not mixed evenly and the presence of sharp particles indicates that the ingredients were not pulverized properly. Bright or bluish-white spots in the powder indicate that the saltpeter has effloresced during the drying process, which will also affect the properties of the mixture.

The powder would then be allowed to run over a sheet of paper and the paper would be examined. Properly made powder should not transfer its color to the paper. If this happens, this indicates that the powder has too much moisture or dust (meal powder).

For prismatic powders, they would check to see if the prisms have smooth surfaces and the edges are sharp and complete. They would also check to make sure that the prisms don't easily crumble or give off too much color when rubbed against a sheet of paper.

The next thing to check was the solidity of the grains of powder. Good quality powder grains should not be easily crushed by finger pressure. It should not fall into dust at once, but should break up into angular splinters. In Germany, they would put 1.1 lbs of powder in a leather bag, which was then put in a glazing drum and rotated for 15 minutes at 15 revolutions per minute. After this, they would take it out and weigh it again and the loss of weight should not be more than 1.55%. In France, they would take an average of various powder samples and dust it initially and then take 8 kg. (17.6 lbs.) of powder and put it in a barrel designed to hold 12 kg. (26.4 lbs.) of powder, which means about 1/3 of the barrel is empty space. This barrel would then be enclosed inside a second barrel and then rolled down an incline of 15 degrees for a length of 5 meters (16.4 feet). The incline was made of planks and at the bottom was a bale of hay to stop the barrel. At the side was another incline made the same way, but falling in the opposite direction. The barrel was allowed to roll down one incline, then sent back down the other incline and the process was repeated 100 times, so that the barrel would have traveled a total of 1000 meters (3300 feet). The powder was then dusted again and the remaining grains were weighed. If the powder did not lose more than 0.20% weight after this test, then it was deemed to be of good quality.

The next process was to examine the size of the grains. They would do this by taking a sample of powder (typically about 2 kg. (4.4 lbs.)) and placing it in a frame with a number of sieves in it and a tray at the bottom. The sieves would have meshes with different sized holes, with the sieve with the largest holes at the top and the sieve with the smallest holes at the bottom. They would place the powder sample on the top sieve and then shake the entire frame for a prescribed amount of time (which depended upon country) and then see how much of the powder sample was held in each sieve. There were quality standards defined for how much each sieve could hold, depending on the powder type. For instance, for good quality rifle powder, no powder must be retained in the first sieve, less than 5% in the second sieve, up to 65% in the third sieve, up to 50% in the fourth sieve and 8% at most in the fifth sieve. Similarly, for good quality cannon powder, no powder must be retained in the first sieve, not more than 5% in the second sieve and no more than 10% in the fifth sieve and all the remaining should be in the third or fourth sieve. 

In France, they would additionally also count the number of grains in a gram of powder sample to check if they were within certain limits depending on the type of powder.

In our next article, we will study some more physical properties they would study to ensure black powder quality.

Saturday, October 22, 2016

Black Powder Substitutes - II

In our last post, we looked at a common black powder substitute: pyrodex. In today's post, we will look at other black powder substitutes.

Pyrodex was one of the first successful black powder substitutes and is therefore well known, since it was first introduced in 1975. However, it still retains the sulfur smell of original black powder and produces a lot of smoke and residue and is corrosive as well, just like original black powder. Towards the beginning of the 21st century, newer powders such as Hodgdon Triple Seven (otherwise called Triple Se7en), American Pioneer Powder (originally sold as CleanShot), Shockey's Gold, Black Mag, Blackhorn 209 Goex Clear Shot and Goex Pinnacle (since discontinued) became available on the market. These powders attempted to correct the deficiencies of pyrodex and original black powder.

Hodgdon Triple Seven Powder and Pellets. Click on the image to enlarge,

Triple Seven powder is made by Hodgdon, the same people that make Pyrodex as well. It was introduced early in the 21st century and is available in both loose powder and pellet form (Hodgdon owns a patent on the cylindrical pellet). This powder is made using carbon from sources other than wood charcoal and contains no sulfur. Therefore, it lacks the typical sulfur smell of original black powder and pyrodex. Like pyrodex, it is classified as a "smokeless powder" and is therefore not subject to the strict rules and regulations that govern the storage and sale of black powder, which means many retailers are likely to sell it in their stores. It is less dense than pyrodex. Unlike pyrodex, the loose powder form is not "volume equivalent" to black powder, as it is hotter burning and about 15% more powerful. Therefore about 85 grains BY VOLUME of triple seven is equivalent to 100 grains of black powder or pyrodex BY VOLUME. The pellets, on the other hand, are formulated to be equivalent to pyrodex and black powder by volume. In addition to the lack of sulfur smell, triple seven powder is cleaner burning, produces lesser smoke, is less corrosive and easier to clean as well, as it dissolves in plain water. The one thing that some shooters complain about is that triple seven powder tends to form a "crud ring", which is a build-up of a hard crust at the location of where the bullet sits on the powder. However, a quick swab of the bore between shots can easily clean this problem. One more disadvantage is that Triple Seven powder is hygroscopic (i.e. it attracts water from the atmosphere), so it can degrade performance if not properly stored. Triple seven powder is a somewhat expensive compared to pyrodex, but is still a popular alternative.

American Pioneer Powder

American Pioneer Powder started off life as "Clean Shot". Like Triple Seven, it uses a different formulation (using ascorbic acid) that reduces the sulfur smell and is easier to clean than black powder. Clean Shot Technologies was sued by Hodgdon for infringing on the cylindrical pellet patent and went bankrupt and a new company, American Pioneer Powder, was formed, which now sells powder under the brands of American Pioneer and Shockey's Gold powder. In addition to loose powder, they also sell it in a compressed stick form, as a work-around the Hodgdon patent. Their powders are reported to clean up easier than pyrodex and triple seven, but some shooters report erratic performance.

Black Mag powders are also based on ascorbic acid and uses potassium perchlorate as the oxidizer. They sold powders under the brands Black Mag2 (equivalent to FFg grain size), Black Mag3 (equivalent to FFFg grain size) and Black Mag XP, as well as manufacturing powders for other companies, such as Alliant Black Dot. While they did have quality control issues, if properly made, it produces fairly consistent performance. It is easier to ignite, leaves less residue and far less corrosive than triple seven or pyrodex. Like triple seven, it is also a hotter burning propellant than pyrodex. Unfortunately, there was an accident at the plant that manufactures these powders in 2010 which led to safety violations charges for the owner and in 2013, he was sentenced and the plant was permanently closed. As part of the sentencing, the owner agreed never to resume manufacturing propellants or even conduct any business in the vicinity of a propellant manufacturing facility.

Blackhorn 209 was introduced by Western Powders in 2008. It is much more non-corrosive and cleaner burning than other powders. The 209 indicates that it requires a 209 shotshell primer for proper ignition. Like some of the other powders above, it is also a "volume equivalent powder" (i.e.) it can be measured using the same powder measure as black powder for identical performance. It has excellent performance and unlike most of the other powders above, it is also non-hygroscopic (which means it doesn't attract water from the atmosphere) and therefore has a longer shelf life. It also doesn't form crud or corrosion like the other substitutes and requires far less cleanup as it is low-fouling in nature.

Thursday, October 20, 2016

Black Powder Substitutes - I

A few posts earlier, we saw a mention of something called "black powder substitute". We will study more about this topic in today's post.

As we saw in several posts on the topic of black powders, it is a mixture that was used as a propellant for hundreds of years. Some of the problems with using black powder include

  1. Ignites very easily and burns rapidly, which may cause accidents if it happens unexpectedly.
  2. Produces a sulfur smell and a lot of residue after burning.
  3. It is hygroscopic and can absorb water from the atmosphere, which causes the powder to degrade.
  4. Needs careful handling and storage to prevent accidents.
  5. Is generally corrosive in nature, which means that firearms need to be cleaned thoroughly after use.
In addition to all the above reasons, black powder also burns less efficiently than modern smokeless powders, which is why most modern firearms use smokeless powders. However, there are still quite a few black powder enthusiasts, who like to use firearms (or replica firearms) that their ancestors used in the past. Due to the unsafe nature of black powder, many areas have special regulations concerning the storage, sale and use of black powder, which makes it hard for people to buy it. This is where black powder substitutes come in.

The most common black powder substitute in use today is called "Pyrodex", which was invented by the Hodgdon Powder Company in 1975.

Pyrodex Powder. Click on the image to enlarge. Public domain image. 

Ordinary black powder can easily be ignited by impact forces, sparks or static electricity, which makes manufacturing and storing it more dangerous. In fact, the last factory manufacturing ordinary black powder in the US was closed in 1970 after an accidental explosion and new regulations came out that made many retailers reluctant to sell black powder any more. In 1975, the Hodgdon Powder Company invented the first black powder substitute: pyrodex.

Ordinary black powder consists of  just saltpeter (potassium nitrate), sulfur and charcoal (carbon). Pyrodex also has these three ingredients, but also contains graphite, potassium perchlorate and some other proprietary ingredients. These additional ingredients make the properties of pyrodex behave more like a smokeless powder and therefore, it is not subject to the same strict regulations of black powder. This means that pyrodex doesn't ignite as easily as black powder and can be stored and transported just like a smokeless powder, which is why many retailers sell it.

Pyrodex is actually about 27.5% less dense than ordinary black powder and is more efficient than it. So how does the substitution work then? Well, when measuring ordinary black powder for muzzleloading weapons, people have always specified powder loads by weight (e.g. grains in the US, grams in most other countries), but they have usually measured it out by volume. What this means is that if a muzzleloading rifle takes (say) 100 grains of black powder as a load, the user doesn't usually actually weigh out 100 grains of powder to load into the rifle. Instead the user has a powder measuring tube, which he (or she) fills with black powder and pours that into the rifle. If the user measures the weight of the black powder from the measuring tube, it will indeed weigh 100 grains (or something close to it). When using pyrodex, the user can use the same measuring tube to measure out a quantity of pyrodex. If the user weighs the contents of the measuring tube, it will weigh around 72.5 grains, since pyrodex is less dense than black powder. However, this 72.5 grains of pyrodex burns with about the same propulsive force as 100 grains of black powder, since pyrodex is a more efficient propellant. Therefore, if the user uses the same measuring tube to measure black powder or pyrodex, one can easily be substituted for the other, without affecting the pressures generated in the rifle. This makes pyrodex a "volume equivalent powder". 

It must be remembered that muzzleloading weapons are commonly loaded by volume using measuring tubes, this works out great when using a volume equivalent powder like pyrodex. However, black powder cartridges are loaded by weight. Therefore, if using pyrodex instead of black powder to load a cartridge, the user must actually load a lesser weight of pyrodex to retain the same amount of propulsive force. 

Pyrodex powder has a similar burning sulfur smell as black powder and is also very corrosive in nature and produces about the same amount of fouling as ordinary black powder. Therefore, users need to perform the same cleaning procedures as when using normal black powder. However, since pyrodex is less susceptible to ignition, it is subject to the same regulations as smokeless powder, instead of the the much stricter regulations of black powder. 

Pyrodex is normally sold in a few grain sizes: Pyrodex RS (Rifle/Shotgun), which is volume equivalent to FFg grain size black powder, and Pyrodex P (Pistol) powder, which is volume equivalent to FFFg grain size black powder. There is also Pyrodex "Select" powder, which is the largest grain size of all and is marketed as an "extremely consistent" grade of pyrodex, meant for muzzleloading rifles. 63.9 grains of Pyrodex "Select" powder have the same volume as 100 grains of black powder.

These days, pyrodex is also sold in pellet form, such as the image below:

Pyrodex pellets. Click on the image to enlarge. 

With this type of pyrodex, the user doesn't have to use a measuring tube to measure out the powder, since the pellets are all of a certain specific size. Instead the user simply takes a pellet or two and loads it directly into the firearm.   

We will study more about black powder substitutes in the next few posts.

Sunday, October 2, 2016

Black Powder Factories - II

In our last post, we studied how early gunpowder factories were often located in the middle of towns in the early days of firearms. Of course, placing a factory within your town walls made sense if you wanted to defend your town walls against attack, but there was the problem of accidents in the factory setting the town on fire. Towards the beginning of the nineteenth century, people began to think more about factory safety and several laws were passed specifying how far away a gunpowder factory could be away from people's houses and how much powder could be worked inside one building and so on. In today's post, we will study how one such factory was set up in the 1860s. Today's object of study will be the Confederate Powder Works.

A view of the remaining chimney of the Confederate Powder Works in Augusta, Georgia
Click on the image to enlarge.

Not much remains of the Confederate Powder Works these days, except for one 150-foot tall chimney, but in its day, it was a massive factory complex laid out over two miles in length and was the second largest gunpowder factory in the world then.

During the days leading up to the Civil War, the Confederate states did not have any significant gunpowder manufacturing facilties, except for a small mill in Tennessee. On July 10th, 1861, Confederate President Jefferson Davis authorized Major George Washington Rains to build whatever was necessary to keep the Confederate armies supplied with gunpowder.

Colonel George.W. Rains. Click on the image to enlarge.
This photograph was taken during the Civil War and is currently in the Augusta Museum of History.

Major Rains spent the next few days living in a railroad car, examining various places for a suitable location for a factory. On July 20th, he selected an area in Augusta, Georgia to be the site of the future factory. The reasons for picking this area for the new factory were several:

  1. It was centrally located and near the junction of some major railroads.
  2. The area was near enough to a big town (Augusta) to provide sufficient workers and materials.
  3. It was far enough from the front-lines that Union forces could not easily attack it.
  4. The Augusta canal and the Savannah river could also be used to transport over water.
  5. The Augusta canal was also a source of water power, which is useful to drive factory machinery.
  6. The area has temperate weather, which means the water supply does not generally freeze during the winter months, thereby ensuring unlimited water power during the whole year.
  7. Since he also intended to produce pure potassium nitrate (saltpeter) in the factory, he also needed abundance of water to wash and refine the minerals.
  8. The canal could also be used to transport supplies and materials from one factory building to the next. 
However, Rains had a few big problems: First, he had no idea about how to build a gunpowder factory, having never been inside one before! Luckily, he came across a book authored by a Major Fraser Baddeley of the Royal Artillery in England, called "Manufacture of Gunpowder as carried out at the Government Factory, Waltham Abbey", that described the entire process and machinery used by the Royal Gunpowder Factory at the Waltham Abbey works in Essex, England. While the book had the descriptions, there were no drawings or plans of the buildings or machines, therefore he had to research on his own to figure these out. Luckily for him, he happened to find an Englishman named Frederick Wright, who had moved to the Southern states and had worked at Waltham Abbey previously, so he asked him for assistance and produced some detailed word descriptions and preliminary sketches. 

The next problem was to find an experienced architect to build the plant while he was occupied with other duties for supplying the existing armies in the field. He hired a couple of young civil engineers/architects, Miller Grant and Charles Shaler Smith to do the job. Construction of the first building started in September 1861. By the time the factory was in full operation, 26 separate buildings were constructed over 140 acres of land that extended almost two miles along the banks of the canal.

The buildings were constructed along the canal, coinciding with the process of making black powder (i.e.) the warehouses to store the raw materials were located first in line, the refinery to refine saltpeter was next and so on, until the final building at the end of the complex, which was used to store the finished gunpowder. The canal was used to transport materials from one building to the next, much like a modern assembly line. The most important buildings were built first: the Refinery, the Incorporating mills, the Mixing house, the Granulating house, the Pressing house and the Drying house and the Boiler house. Other buildings include a blacksmith's house, the stables, a carriage house, a laboratory etc. We will discuss the construction and use of these buildings in the next post or two. The refinery building in particular, was very beautiful to look at, being constructed in a Gothic revival style, influenced by the Smithsonian Institution in Washington DC and the British Houses of Parliament. The chimney in front of the refinery was shaped like an obelisk and is the only structure that survives today, located at 1717 Goodrich Street in Augusta. The buildings were separated from each other and designed to survive explosions, in accordance with the safety procedures used in other gunpowder factories in the 19th century.

The first gunpowder in the factory was made on April 13th, 1862; just nine months after Rains had been authorized to build the factory and construction of new buildings continued as the factory expanded. The factory remained in operation until the surrender of the South during the end of April 1865, which means it remained in operation for a little over three years. During this time, it managed to produce approximately 2,750,000 pounds of gunpowder at an average rate of around 7,000 pounds a day. In addition to this, the factory also produced other war material, such as time fuses, artillery pieces, wagons etc. Due to his efforts in building the factory, Major Rains was promoted to a full colonel by the end of the war.

After the Civil war ended, the factory fell into ruin. In 1872, a project to widen the Augusta canal resulted in most of the buildings to be destroyed, leaving only the tall chimney that can still be seen today. The chimney was spared, at the request of Colonel Rains, as a memorial to those who died in the Southern armies during the Civil war.

A view of the chimney as it exists today, courtesy the Augusta Historical Society.
Click on the image to enlarge. 

In 1880, a new mill was constructed in the old powder works area, called the Sibley cotton mill owned by the Sibley family. Bricks from the demolished buildings were used to construct the new mill and it was built with the appearance of a medieval castle or fortress, similar to the powder works buildings that it replaced.  The cotton mill was very successful and remained in operation until around 2006, making denim cloth for major clothing manufacturers. While the mill production has ended, the water-driven turbines still remain in operation and generate electricity that is sold to Georgia Power even today.