Arkansas Sharpening Stone

Knife blades wear out over time, and you have to use a whetstone to restore their sharpness. A whetstone is a special stone for sharpening cutting tools, which removes wear and restores their sharpness. Let us take a closer look at one of the most popular sharpening whetstones: Arkansas natural sharpening stone.

What are Arkansas sharpening stones

Arkansas stones are made of Novaculite and characterized by uniformity and a degree of purity within 99.5% (SiO2 content). They are used for high-quality sharpening of cutting tools.

The origin or where these stones come from

They are natural abrasives that are mined in the United States and were named after the Arkansas state. These stones are quarried according to open-сut mining technique at a depth of almost 20 meters. The material is considered rare because its only deposit is in the Ouachita Mountains of Arkansas. Locals obtained stone from riverbeds, particularly the river that bears the same name.

The hardness of the stone complicates the process and makes the work time-consuming. Experts acquire the rock and proceed to cut out the blocks. They then meticulously split these blocks into the required dimensions, ensuring to maintain the integrity of the grit quality and prevent any damage to the abrasive structure.

No one knows the exact age of the stones. Experts assume that they are as old as 250 million years! For some time the Arkansas stones served as a track ballast material. They were used as a filler on railway tracks during the times of steam locomotives. During the World War II, Arkansas stone was considered a strategic raw material for the military industry.

Arkansas stone consists of quartz crystals (silicon dioxide, also known as silica). It has a fine grit. The grit size is within 1-6 microns. The symplectic structure provides the stone with strong bonds between the fractions.

Despite concerns about the depletion of these natural resources, current data indicate that the supply of novaculite suitable for sharpening stones is still abundant. The amount of novaculite in the Ouachita Mountains is sufficient to continue sharpening stone production in Arkansas for the foreseeable future.

Types

According to the degree of hardness, Arkansas stone is divided into the following types:

• Washita. The bars of this type have a medium grit size. Their main use is coarse sharpening of cutting tools, they do not require soaking. Applying cutting oil provides the best processing of the blade. This stone can be gray, brown and black. The approximate grit size is 400-600.
• Soft Arkansas. Stones of the soft Arkansas type have a finer grit size. This abrasive is used for the main sharpening stage. The grit size is around 600-800.
  
• Hard Arkansas. The hard Arkansas type has a fine grit size. Therefore, they use them for pre-finishing and finishing of blades. Using them to sharpen the knife edge makes it razor sharp. These natural stones can have various colors and shades. They do not require soaking. Applying cutting oil provides the best processing of the blade. The grit size is in the range of 1200-2000.
  
• Black Arkansas. The hardness of the Black Arkansas abrasives is in the range of 7-9 on the Mohs scale (hardness scale, where 10 is the maximum index). That is why you get sharp blades. The structure is microcrystalline, the color palette is dark gray—black. Approximate grit size in the range of 2000-3000.
  
• Translucent Arkansas. This bar is usually translucent with a yellowish tinge. Arkansas stones have a dense texture and produce super sharp blades. The highest grit size is 3000-8000.
  

Novaculite is a common name for these natural stones.

Options

You can find this bar in stores in four options:

1. Flat end whetstone. Best for manual sharpening.
2. Mini stone. The most suitable option for sharpening small cutting tools.
3. Rectangular apex sized bars. Most convenient option to use with guided sharpeners.
4. Cones and circles. They are used with grinding machines.

Sometimes professionals have all stone options in their arsenal.

The sharpening process

Arkansas stones' varying grit range allows you to select the right bar for sharpening cutting tools according to consumer's needs. They come with different grain sizes. It turns out practical when you need to do a complete sharpening of a blade. You remove the burrs with a coarse abrasive and profile the edge. Then you use a fine stone to finish the blade surface. And here is an answer to why you should possess different grit stones.

Sharpening stages:

1. First, you have to position the knife to the abrasive surface while maintaining the sharpening angle, depending on the knife type and purpose.
2. Then you make steady motions (edge leading — edge trailing) along the entire blade length.
3. While monitoring the amount of metal that you remove from the bevel, sharpen the knife on a coarse grit stone, alternating between blade sides.
4. Continue repeating the previous steps, but now with a finer stone. And change it to even finer stones every time you finish processing both blade sides.

All Arkansas abrasives, including hard and black, allow you to sharpen the blades to a mirror shine.

Areas of application

Arkansas stones have a broad range of applications. Let us highlight some of them in which they provide high-quality sharpening:

• Medicine. Arkansas abrasive stones are useful for sharpening various medical and surgical instruments: needles, scalpels, scissors, dental tools, etc. Arkansas natural abrasives quickly return the sharpness of the cutting edge to surgical tools. They are also used for polishing implants and their finishing before installation. Therefore, surgeons and dentists should have such abrasives in their arsenal.
• Cooking. Knives and other cutting objects are used in this field to slice meat, vegetables, and fruits. Arkansas bars are used here to hone the cutting tools, enhance their sharpness, and improve their efficiency during the cooking process.
• Gardening. It involves the sharpening of shovels, prunes, and other gardening equipment. Even here, it is highly recommended to have an Arkansas item in your toolbox.
• Jewelry. The Arkansas whetstones' fine grit and hardness make it easy to sharpen the cutting edges of jewelry tools with precision. Jewelers also use them for polishing gemstones and giving them a shining surface.
• Hunting, fishing. Novaculite stones have also proven effective in making sharp edges of machetes, hunting and bushcraft knives, along with various other fishing and hunting tools.
• Shaving. If your purpose is to attain a razor-sharp edge when sharpening a blade, it is recommended to have black and translucent stones.
• Carpentry and handicraft works. On top of that, these natural stones come in great use for sharpening chisels, carving blades, plane irons, and other cutting and woodworking equipment.

Storage and proper care

Proper storage will give Arkansas stones a long and satisfying performance during their service life. We recommend storing the item in a dry place, inside a wooden box or case. Because moisture will gradually destroy its structure and deteriorate its sharpening capabilities. It is also necessary to protect natural fragile abrasives from impacts to avoid damage to the surface.

We also recommend keeping the bars out of direct sunlight. Due to the fact that UV exposure will have a negative effect on the structure of the stone. Remember to store each item of a different type or grit level separately. This will prevent damage as well as infection of the fine grit stones by coarser grits.

Remember to avoid serious temperature fluctuations in your storage area. Do not forget to clean the stones and do regular flattening. You will notice metal burrs and abrasive residue remaining on the surface after work. Use a soft cloth and water for this. To flatten the stone surface and remove deformations you will need a hard lapping stone or tempered glass and powder grits.

Advantages of Arkansas stones

Compared to other sharpening stones, Arkansas has the following advantages:

• Good wear resistance.
• Increased hardness.
• Long-term service life.
• They work with oil, which makes the process cleaner.
• High-quality and clean surface finish.
• They do not heat up during work.
• Do not scratch the surface.
• They are capable of sharpening any steel.
• Another great feature is that they contain no harmful impurities.

Arkansas stones retain high-performance properties for a long time, which allows you to use them to give your knives perfect sharpening.

Where to find them

You can find Arkansas stones in physical and online stores that offer sharpening supplies. You can find four types of these stones available in stock in the TSPROF online store. Soft, Hard, Black, and Translucent stones, along with a convenient aluminum backing plate with a sticky layer that facilitates their use with TSPROF sharpeners.