From DIYinfo.org
Sharpening stones are used to produce the sharp cutting edges of tools or machinery cutters Their shape can be either rectangular, called OILSTONES or shaped, known as SLIPSTONES and are produced by Natural or Artificial means.
[edit] Natural Oilstones
These are quarried from the ground and cut to convenient sizes. Most common 200 x 50 x 25 mm.
Turkey oilstone:
These are expensive and difficult to obtain but produce an extremely keen edge, ideal for carving tools etc.
Arkansas oilstone:
Available in both black and white, the black being the better quality but is generally considered too slow for woodworking tools.
Washita oilstone:
The 'Lily White' variety is a good fine grained stone producing an excellent edge for woodworking tools.
[edit] Artificial Oilstones
These are man made stones of artificial abrasive grit such as silicone carbide, aluminium oxide and emery, they are less expensive more readily available in various grades, have an even texture and cut faster than natural stones.
Identifying Artificial stones:
Silicon carbine is a dark grey colour. ‘Carborundum’ is a trade name for silicon carbide. Aluminium Oxide is a redish brown colour. Alundum is a combination of aluminium oxide and silicon carbide.
India stones:
These are made from alundum grit with the properties of uniformity toughness, hardness and grit sharpness, they are available in course, medium or fine grade with the fine grade very suitable for woodworking purposes.
Combination stones: These are made by combining course and fine, or medium and fine grades of grit on opposite surfaces of the stone making it more versatile.
[edit] Oilstone Maintenance
To keep oilstones in good condition the following points should be observed.
- House the oilstone in a suitable protective box.
- Use a suitable lubricant, e.g. neatsfoot oil or a mix of 2 parts kerosene and 1 part light oil.
- Promote even wear by using the entire surface of the stone during sharpening, not just the center.
- ‘Dress’ the stone if necessary using carborundum grit or fine sand with water, whilst rubbing the stone on a flat concrete slab.
[edit] Slipstones
Slipstones can be described as small oilstones but produced in various shaped profiles for the purpose of sharpening curved or shaped blades or tools (e.g. gouges, machine cutters etc.). They also are available in similar grades as oilstones.
[edit] Diamond Dust Coating
Sharpening instruments e.g. rectangular large and small cylindrical sharpening sticks are available for use and perform equally well with either oil or water. As the surface wears more diamond points are exposed increasing the speed of sharpening. Various grades from fine to course are procurable.
