SHARPENING BLADE SHEARS

New Zealand Journal of Agriculture, Volume 71, Issue 4, 15 October 1945, Page 383

SHARPENING BLADE SHEARS

By

R. FINDLAY,

Organiser, Otago Provincial

Council, N.Z.' Farmers’ Union.

THE author of this article assisted during the first few years of the war as blade shearing instructor at the Roxburgh Shearing Classes which were organised by the Otago and Central Otago Councils of Primary Production to help to alleviate the shortage of shearers. Mr. Andrew Gibson, of Millers Flat, who has also given instruction at the above classes, has assisted in the compiling of this description and his help is gratefully acknowledged. The sound tuition imparted by those associated with the shearing classes has helped many young men during the last few years to become acquainted with the art of shearing, and a good number have since become expert shearers. The ranks of shearers, especially with the blades, have become sadly depleted. No doubt the example of the Roxburgh and Millers Flat farmers in organising annual shearing classes could with advantage be followed by others in different parts of the Dominion. The following description of sharpening blade shears, although not as adequate as personal tuition, may assist learners to perform that very essential operation which is the keystone to successful shearing.

ALTHOUGH shearing machines have largely dis- >■ placed the blades on the low country, blade shearing is still very prominent on the high-country sheep stations of the South Island. On account of the likelihood of sudden cold changes, especially on the higher levels to which sheep are mustered after shearing, it is desirable to leave more wool on the sheep, especially along the back where it can protect the kidneys. Unfortunately blade shearing does not seem to be as popular with learners as the machines, partly owing to the fact that machine shearing is probably easier on the operator, and also the latter is quicker, so that more sheep can be shorn in a given time. The first so-called advantage is sometimes a matter of opinion, as some shearers prefer to use the blades even when expert in both methods of shearing; the second is compensated to a certain extent by a difference of shearing rates, the award rates at present being 35/6 per hundred for blades, as against 33/- for machines. The learner will find, however, that having become adept at blade shearing, it is relatively easy to pick up machine shearing, whereas it is somewhat difficult to change to blades when the learner has been taught the use of machines exclusively. For this reason

learners at some shearing classes are taught the rudiments of blade shearing before proceeding to use the machines. It is simpler to learn the various holds on the sheep and the methods of turning the animal with shears in the hand. The possession of a rattling handpiece in the one hand and a kicking sheep in the other is more likely to upset the concentration of the learner, whose first efforts should be directed to handling the animal without undue exertion.

It is also useful to know something of blade shearing in cases of emergency or for casual operations which do not require the starting of a machine-shearing plant. Shears are used frequently for various odd jobs on the farm, and the facility with which they are carried out depends very often on the sharpness of the instrument. With shearing, sharpness and proper setting of the blades are all important,' and learners should be given for the first task the sharpening and setting of the blades.

The Shears

A new set of blades (Fig. 1) taken out of the packet may appear impressive and sharp enough for general purposes. Nevertheless, a good deal of attention is required before they can be used for shearing, and the operations which are to be described will make not only for ease of cutting, but also for less effort on the part of the shearer. The sharp edges so necessary for successful shearing will also be maintained for a longer period if the blades are properly set. In any alterations

made it is always necessary to maintain as far as possible the makers’ “set.”

Pulling Back

The operation known as “pulling back” (Fig. 2) is carried out so that the shears will take more wool in each cut (Figs. 3 and 4). This pull is imparted in turn to each blade, which is held in a vice. The pull should be straight back towards the operator, who may use a cloth round the blade to get the necessary purchase on the blade. The pull must be even on each blade so as to maintain the makers’ set, and no bend must be put on the blade when carrying out this operation. A clamp for the purpose which ensures that no twist is imparted to the blade is on the market. The diagram on the opposite page shows the position of the blades at each stage of pulling back, finishing up with both being even in relation to one another. Any unevenness should be immediately rectified.

This is done by using a wrench on the shears, one blade of which is held in a vice (Fig. 5). The wrench is applied to the handle of the blade in the vice. Pulling or forcing the wrench will have the effect of taking the free blade either off or on. The pulling adjustment would be made if one blade was against the back of the opposite blade when the shears are closed, a condition resulting in the close running blade soon having its edge taken off during shearing.

If the blades are “running too wide,” the reverse motion will be applied to the wrench, and this forces

the free blade towards the fixed one. Should : the operator examine a new pair of shears before setting he will see the desired set.

The Knockers

The cutting out of a small piece of metal (Fig. 6) from the knocker and substituting a piece of leather or other material are said to prevent jar on the operator, although the main function is to eliminate the excessive noise which occurs when two pieces of metal repeatedly come together. A small piece of metal about fin. from the edge is first taken out of each knocker with a hacksaw. When this has been completed the shears should slightly overlap at the point when closed. A piece of leather (Fig. 7) about lin. by fin. is then laid over the cut surface and the strings, which have previously been threaded through - the leather, are tied back (Fig. 8). The knots should be tied underneath so that they will not be in contact with the shearer’s hand. After adjusting the leather the shears when closed should be nearly meeting at the point. The leather is then trimmed (Fig. 9) so that the bottom edge of the opposite blade will not touch the knocker when closed. Sometimes a piece of cork set in with sealing wax is used instead of leather.

The Driver

The driver consists of a piece of webbing or light pliable leather formed into a loop into which the hand fits, enabling the shearer to retain a firm grip on the shears and to assist the blades to open without losing

control. The driver is fitted either from the top of the handle of the top blade to the bow of the bottom blade, or from the handle of the top blade to the junction of the bows (Fig. 10). The material is firmly tied with seaming twine, which is bound tightly round the bow and the driver at each end.

Sharpening Blades

A grindstone is used to put a sharp edge on each blade and the stone used should preferably be even across the top, without any dip or bump in the middle. Each blade should be held flat across the grindstone with a good solid grip (Fig. 11), the left arm held in at the side and the bow of the shears resting on the body (Fig. 12). The thumb of the right hand is braced on the knocker of the blade on the grindstone to give leverage to the fingers of the right hand, which hold the upper blade away from the lower one during grinding. As the grindstone revolves, the blade should be gradually moved across from left to right and back from right to left so that the whole blade is engaged on the grindstone evenly. Grinding is continued until one can just see a thin white line running down the edge of the blade. The chisel edge so formed should not be more than about fin. wide for a start. Each succeeding sharpening will take it further back. If the blade has been held evenly on the grindstone, it will not be over-ground in one part and under-ground in another, and the thin white line will be of an even width along its entire length.

After both blades have been ground the sharp points of the blades should be taken off on the grindstone (Fig. 13) so that the points do not catch the skin of the sheep, which could cause a good deal of damage. The points are tested on the hand for sharpness (Fig. 14).

The Oilstone

After a satisfactory edge has been put on by the grindstone it is necessary to use a fine oilstone to take the roughness off the blades and to put on a short bevel with a razor-like edge. This : is done merely to obtain a fine finish and should not be used for work which can be done more satisfactorily and more easily on the grindstone. A notched peg is often used to hold the blade when using the oilstone (Fig. 15). After using the oilstone on the sharpened edge it is necessary to “back off” so as not to leave a rough or feathery edge. Backing off is done by drawing the oilstone flat (Fig. 16) across the back of the blade, starting at the heel and going to the point.

General

Having satisfactorily sharpened and set the shears, the learner may proceed to try his hand at shearing. In this it is important to keep the blades sharp and immediately to correct any fault which may become apparent. The blades may need slight adjustment with the wrench as described, or the “driver” may not be to the shearer’s liking and should be altered to suit

the hand. A quick wipe over with the oilstone is desirable after each sheep, but at mealtimes and “smoke-o” a little more attention should be given to the shears. Most shearers carry two or three pairs and do them up each night.

The shears must be ground every night to take off the bevel edge previously put on by the oilstone, but when shearing “hard” sheep, when a lot of oilstone sharpening is required, the shears may have to be ground more often.

EUROPE. As a result of wartime disorganisation of transport facilities, the accumulated effects of fertiliser shortage, lack of manpower, destruction of livestock,, losses of tractors, destruction of levees and dykes, and temporary disorganisation of production caused by the redistribution of large estates in Poland, Hungary, Rumania, Yugoslavia, and Italy, combined with destruction of processing plants, Europe remains desperately short of food. It has been calculated that on . the basis of European production millions of Europeans would be on but half of pre-war intake of energy foods, and that 12 million short tons of food will be required to be imported during Wheat, fats, animal protein foods, and sugar are most urgently needed. Depending on the availability of shipping, the wheat situation might be met from Canada and the United States, but there appears to be a world-wide shortage of the other items. —Foreign Agriculture U.S.D.A., June, 1945.