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Sharpening Stones.

On the matter of sharpening stones, in general terms, there are a number of different types of stone available,

a. Artificial stones sometimes called is a whetstone. Whetstone is not a misspelling of wetstone. Whet is an old English/Germanic word for ‘to sharpen’ as in to whet your appetite, to sharpen or excite it.
Made of abrasive grit, often aluminium oxide, bonded together to form the stone. These come in a number of different grit sizes and in a selection of shapes to suit various jobs.

Ceramic stones.
These stones are extremely hard and are mostly used for the final honing stages of sharpening. They are made of hard ceramic powders mixed with zirconium oxide or aluminium oxide.

They do tend to clog very quickly making it necessary to keep them very clean. If you don’t keep them clean they’ll get very slow at sharpening.

Another downside of these is that because of how hard they are they need a light pressure otherwise you will take off too much metal.

b. Natural stone such as the well-known Arkansas stone.
The real stone is mined in Arkansas in America, this comes in various hardness’s and a variety of shapes, Arkansas stones come in a variety of grits, sizes and shapes. The Arkansas stones are graded by their hardness, with five different grit sizes. Soft Arkansas is the lowest of the grits, comparable to an American 400-600 grit synthetic stone. Up next are the Hard Arkansas (800-1000 grit), Hard Black Arkansas (2000-3000 grit) and Surgical Black Arkansas (4000-6000 grit). The highest of the grits is Translucent Arkansas, comparable to an 8000-10.000 grit synthetic stone. If you can get your hands on one of these look after it like a friend, it will last you years and years.

Another very good natural whetstone is the yellow-grey Belgian Coticule which is legendary for the edge it can give and has been quarried for centuries from the Ardennes. The slightly coarser and more plentiful Belgian Blue whetstone is found naturally with the yellow coticule in adjacent strata; hence two-sided whetstones are available, with a naturally occurring seam between the yellow and blue layers. These are highly prized for their natural elegance and beauty, and for providing both a fast-cutting surface for establishing a bevel and a finer surface for refining it. This stone is considered one of the finest for sharpening.

Diamond sharpeners.
These last a long time, will not need to be flattened but tend not to be as fine as a natural stone or a ceramic one.

Any hard stone will sharpen when it comes down to it, it’s just that the stone made for the job will do it better.
If you have one of the larger bench stones (an oblong block) or even a smaller version of it, do make a strong wooden box with a top to hold it, this will help prevent it from getting damaged and dirty.
Always use a lubricant when using a sharpening stone, it helps to make a sort of grinding slurry and to wash away the little bits and it will stop the stone getting clogged up with oil.
Any light oil is what is normally used though if you get a Japanese water stone you should use water as the lubricant, in this case, put the stone into water for fifteen minutes or so or until any air bubbles stop coming out.
After use with oil clean your stone with a cloth.
If you have a very clogged up stone that has become almost unusable, you can clean off the oil with washing up liquid or put it into an ultrasonic cleaner.

Grades of water stones.

If you can’t get a really fine stone, make one.

Get an ordinary grindstone and use it without any lubricant, after a while it will get clogged up and thus be much smoother.
You will find that after a lot of use the large sharpening stone will lose its flatness in the middle, this happens because you have used the middle more than the sides it’s something that can’t be helped other than making an effort to move your knife over the whole stone.
The problem is that when you come to sharpen a wide blade you won’t be able to do it because only the outside of the blade will be touching the stone.
When your stone gets to this state you will have to flatten it, this is how it is done:
Get together the following items,

a. A piece of good window plate glass about 6mm thick or thicker, the sort of glass used in shop windows, if you go to a place that sells glass there is bound to be a piece large enough in the scrap bin, it will need to be about 1-foot square. Ask the shop to grind the edges to remove any sharp points.

b. Some ordinary oil.

c. Some grinding powder of the kind used in garages to grind the valves in an engine.

Draw a grid pattern on the stone with a pencil, this will give you a guide as to where the high and low spots are after you have done the initial flattening.
Place your glass sheet on a flat surface, mix up some of the grinding powder with some of the oil, spread it on the glass then put your sharpening stone on to the glass with the damaged side downwards and slowly start to rub the stone round and round with random movements.
After a while you may have to add more oil and grinding powder.
Inspect the stone from time to time with a straight edge and look at the pencil marks, as it gets flatter the pencil marks will slowly go. It will take you some time to get it flat but you will get there in the end.

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