Under the Choko Tree By Nevin Sweeney

Tool Sharpening - Part 1: Grinding and Sharpening Equipment

Thirty years ago an old friend of mine by the name of Bill Tarplee was operating a magazine out of Canberra and he wrote a series of articles on tools. Bill was a manual arts teacher at one stage, very skilful with his hands and knows all that there is to know about hand tools, their care and sharpening. I have been lucky enough to secure his permission to republish some of his original articles.

This one was first published in July 1981 and is the first in a series of three about tool sharpening. Where possible I have tried to reproduce his drawings and photos from the original article, but some of the drawings were very small and some of the photos did not reproduce well. Where required I have replaced them with photos of my stuff.

By Bill Tarplee


There comes a time in the life of all cutting tools, be they planes, chisels, axes or scythes, when the cutting edge has finally worn to such a degree that it is necessary to renew the edge to its original state of sharpness. Sharpening is a far simpler process than many realise, and one that is well within the basic abilities of most, if they understand the rules and principles involved.

Grinding is the fast removal of metal using a rotating abrasive wheel either motorised as per electric grinder or hand turned grinder. Occasionally one sees an old fashioned hand or treadle actuated sand or wet stone. (There are plenty of the former types, very few of the latter.)

Electric Grinding Wheel

The electric grinder (emery wheel) is a most useful tool. With a properly selected wheel of suitable grade, it will remove metal very quickly. Unfortunately this very speed produces heat, and unless one is very careful the steel can be ruined if the heat reaches a high degree and the temper becomes drawn.

Hand Turned Grinding Wheel

The wetstone is so named because the wheel is partially immersed in water. The water is carried around the wheel as it is slowly turned. The water serves to keep the steel cool and to wash away particles of steel that would otherwise clog the stone. The cutting action is much slower than an emery wheel, which is a major reason for wetstones losing popularity.

When ground by either of the above methods it is still necessary to hone the tool to remove the rough and serrated edge left by grinding, and give a true and keen cutting edge.

NOTE: when grinding use the full face of the wheel to prevent uneven wear of the wheel. The sides of the wheel should not be used for grinding. Worn wheels can be trued and refaced to expose a new cutting surface with the aid of a wheel dresser or diamond ‘stick’.

Honing is the removal of metal by rubbing the metal on a ‘stone’, the surface of which has been covered by a layer of fluid, be it oil or water based.

‘Stones’ come in various forms and grades and may be divided into two types. Those that are man-made and those that are of natural formation.

The artificial or ‘man-made’ are the type that you buy at any hardware store and are usually termed ‘carborundum’; though they may also be a form of aluminium oxide. They are good stones and work well, though in my opinion most are far too coarse.

Natural stones are mined. They are usually of a sandstone origin, but may also be marble, slate, or on occasion, shale. The best, and the best known natural stones are Arkansas and Washita stones. All natural stones are costly when compared to artificial stones, and as a rule are too fine for average home use.

In my mind, a suitable grade artificial stone is one on which the edge of your thumbnail can be rubbed, without the sensation of abrasion, although the thumbnail will be rapidly abraded away. Anything coarser is too coarse. Most cheap commercial stones are far too coarse, even on the ‘smooth’ side.

If you decide to buy a natural stone get either a ‘soft Arkansas’ which is medium grade or a Washita which is coarse grade (but still very much finer than most ‘fine’ artificial stones). To buy either ‘fine’ or ‘extra fine’ Arkansas stones is a waste of money unless you have the skill to use the stone, and have particular requirements than need ultra-sharpness. Only very fine steels can be sharpened to this degree.

All stones, whether artificial or natural, need a liquid cover to wash away particles of stone and steel which will stop the stone clogging. A 50/50 mixture of car oil and kero will do well. Neatsfoot oil is a very good honing oil, but it is more costly and hardens in cold weather. I prefer it myself as it gives a better cutting and washing action.

When using a stones for honing, try and use the whole surface of the stone. Don’t abrade on the same spot or you will quickly wear a hollow at that point and thus ruin the stone.

NOTE: I’ve purchased badly worn stones in second hand shops for nominal prices. They can be refaced using a bucket of sharp sand and a hard flat surface. Put some of the sand on a hard flat surface such as a piece of marble, a big quarry tile, or a piece of glass. Wet the sand with water and rub the stone back and forth to abrade away the high spots. Keep plenty of water and sand on the surface to speed the cutting. Also, turn the stone end about frequently, and keep shifting the stone to different parts of the surface so that it will remain flat and true.

All stones should be protected when not in use. A special box is best suited to this purpose. The traditional oilstone box is made from a piece of scrap timber, as shown below. With my oilstones I’ve marked the end of the boxes A and B. I make it a policy to alternate the ends each time I use the stone in an effort to keep the stone as flat as possible.

Grinding and sharpening angles will vary from tool to tool, but usually are about 25⁰ - 30⁰ for the grinding angle and 30⁰ - 35⁰ for the sharpening or honing angle. The sharpening facet must be kept as short as possible and the blade reground once the facet has become too large a proportion of the grinding facet.

Part 2 – Sharpening Plane Irons Chisels and Knives

Part 3 - Scissors

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