Carpentry for Boys Part 2

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[Ill.u.s.tration: _Fig. 15._]

When the saw is placed between these clamps and held together by the jaws of the vise, you are ready for the filing operation. Observe the following _filing suggestions_: Always hold the file horizontal or level. In filing, use the whole length of the file. Do the work by a slow, firm sweep.

Do not file all of the teeth along the saw at one operation, but only the alternate teeth, so as to keep the file at the same angle, and thus insure accuracy; then turn the saw and keep the file constantly at one angle for the alternate set of teeth.

Give the same number of strokes, and exert the same pressure on the file for each tooth, to insure uniformity. Learn also to make a free, easy and straight movement back and forth with the file.

THE FILE.--In order to experiment with the filing motion, take two blocks of wood, and try surfacing them off with a file. When you place the two filed surfaces together after the first trial both will be convex, because the hands, in filing, unless you exert the utmost vigilance, will a.s.sume a crank-like movement. The filing test is so to file the two blocks that they will fit tightly together without rolling on each other. Before shaping and planing machines were invented, machinists were compelled to plane down and accurately finish off surfaces with a file.

In using the files on saws, however small the file may be, one hand should hold the handle and the other hand the tip of the file.

A file brush should always be kept on hand, as it pays to preserve files by cleaning them.

[Ill.u.s.tration: _Fig. 16._]

THE GRINDSTONE.--As most of the tools require a grindstone for sharpening purposes, an ill.u.s.tration is given as a guide, with a diagram to show the proper grinding angle. In Fig. 16 the upright (A) of the frame serves as a line for the eye, so that if the point of the tool is brought to the sight line, and the tool (C) held level, you will always be able to maintain the correct angle. There is no objection to providing a rest, for instance, like the cross bars (D, D), but the artisan disdains such contrivances, and he usually avoids them for two reasons: First, because habit enables him to hold the tool horizontally; and, second, by holding the tool firmly in the hand he has better control of it. There is only one thing which can be said in favor of a rest, and that is, the stone may be kept truer circ.u.mferentially, as all stones have soft spots or sides.

IN THE USE OF GRINDSTONES.--There are certain things to avoid and to observe in the use of stones. Never use one spot on the stone, however narrow the tool may be. Always move the tool from side to side. Never grind a set of narrow tools successively. If you have chisels to grind intersperse their grinding with plane bits, hatchet or other broad cutting tools, so as to prevent the stone from having grooves therein.

Never use a tool on a stone unless you have water in the tray.

[Ill.u.s.tration: _Fig. 17. Correct manner of holding tool._]

[Ill.u.s.tration: _Fig. 18. Incorrect way of holding tool._]

CORRECT WAY TO HOLD TOOL FOR GRINDING.--There is a correct way to hold each tool; see ill.u.s.tration (Fig. 17). The left hand should grasp the tool firmly, near the sharp edge, as shown, and the right hand should loosely hold the tool behind the left hand. There is a reason for this which will be apparent after you grind a few tools. The firm grasp of the left hand gives you absolute control of the blade, so it cannot turn, and when inequalities appear in the grindstone, the rigid hold will prevent the blade from turning, and thus enable you to correct the inequalities of the stone. Bear in mind, the stone should be taken care of just as much as the tools. An experienced workman is known by the condition of his tools, and the grindstone is the best friend he has among his tools.

INCORRECT WAY TO HOLD TOOL FOR GRINDING.--The incorrect way of holding a tool is shown in Fig. 18. This, I presume, is the universal way in which the novice takes the tool. It is wrong for the reason that the thumbs of both hands are on top of the blade, and they serve as pivots on which the tool may turn. The result is that the corners of the tool will dig into the stone to a greater or less degree, particularly if it has a narrow blade, like a chisel.

Try the experiment of grinding a quarter-inch chisel by holding it the incorrect way; and then grasp it firmly with the left hand, and you will at once see the difference.

The left hand serves both as a vise and as a fulcrum, whereas the right hand controls the angle of the tool.

[Ill.u.s.tration: _Fig. 19._]

These remarks apply to all chisels, plane bits and tools of that character, but it is obvious that a drawknife, which is always held by the handles in grinding, and hatchets, axes and the like, cannot be held in the same manner.

A too common error is to press the tool too hard on the stone. This is wrong. Do not try to force the grinding.

Then, again, it is the practice of some to turn the stone away from the tool. The stone should always move toward the tool, so as to prevent forming a feather edge.

THE PLANE.--Indiscriminate use of planes should be avoided. Never use the fore or smoothing planes on rough surfaces. The jack plane is the proper tool for this work. On the other hand, the fore plane should invariably be used for straightening the edges of boards, or for fine surfacing purposes. As the jack plane has its bit ground with a curved edge, it is admirably adapted for taking off the rough saw print surface.

THE GAGE.--The ill.u.s.tration (Fig. 19) shows one of the most useful tools in the kit. It is used to scribe the thickness of the material which is to be dressed down, or for imprinting the edges of tenons and mortises.

Two should be provided in every kit, for convenience.

The scribing point should be sharpened with a file, the point being filed to form a blade, which is at right angles to the bar, or parallel with the movable cheekpiece.

CHISELS.--I have already pointed out, in general, how to hold tools for grinding purposes, this description applying particularly to chisels, but several additional things may be added.

Always be careful to grind the chisel so its cutting edge is square with the side edge. This will be difficult at first, but you will see the value of this as you use the tool. For instance, in making rebates for hinges, or recesses and mortises for locks, the tool will invariably run crooked, unless it is ground square.

The chisel should never be struck with a hammer or metal instrument, as the metal pole or peon of the hammer will sliver the handle. The wooden mallet should invariably be used.

GENERAL OBSERVATIONS.--If the workman will carefully observe the foregoing requirements he will have taken the most important steps in the knowledge of the art. If he permits himself to commence work without having his tools in first-cla.s.s condition, he is trying to do work under circ.u.mstances where even a skilled workman is liable to fail.

Avoid making for yourself a lot of unnecessary work. The best artisans are those who try to find out and know which is the best tool, or how to make a tool for each requirement, but that tool, to be serviceable, must be properly made, and that means it must be rightly sharpened.

CHAPTER III

HOW TO HOLD AND HANDLE TOOLS

Observation may form part of each boy's lesson, but when it comes to the handling of tools, practice becomes the only available means of making a workman. Fifty years of observation would never make an observer an archer or a marksman, nor would it enable him to shoe a horse or to build a table.

It sometimes happens that an apprentice will, with little observation, seize a saw in the proper way, or hold a plane in the correct manner, and, in time, the watchful boy will acquire fairly correct habits. But why put in useless time and labor in order to gain that which a few well-directed hints and examples will convey?

Tools are made and are used as short cuts toward a desired end. Before the saw was invented the knife was used laboriously to sever and shape the materials. Before planes were invented a broad, flat sharpened blade was used to smooth off surfaces. Holes were dug out by means of small chisels requiring infinite patience and time. Each succeeding tool proclaimed a shorter and an easier way to do a certain thing. The man or boy who can make a new labor-saving tool is worthy of as much praise as the man who makes two blades of gra.s.s grow where one grew before.

Let us now thoroughly understand how to hold and use each tool. That is half the value of the tool itself.

THE SAW.--With such a commonplace article as the saw, it might be a.s.sumed that the ordinary apprentice would look upon instruction with a smile of derision.

HOW TO START A SAW.--If the untried apprentice has such an opinion set him to work at the task of cutting off a board accurately on a line. He will generally make a failure of the attempt to start the saw true to the line, to say nothing of following the line so the kerf is true and square with the board.

HOW TO START ON A LINE.--The first mistake he makes is to saw _on the line_. This should never be done. The work should be so laid out that the saw kerf is on the discarded side of the material. The saw should cut alongside the line, and _the line should not_ be obliterated in the cutting. Material must be left for tr.i.m.m.i.n.g and finis.h.i.+ng.

THE FIRST STROKE.--Now, to hold the saw in starting is the difficult task to the beginner. Once mastered it is simple and easy. The only time in which the saw should be firmly held by the hand is during the initial cut or two; afterwards always hold the handle loosely. There is nothing so tiring as a tightly grasped saw. The saw has but one handle, hence it is designed to be used with one hand. Sometimes, with long and tiresome jobs, in ripping, two hands may be used, but one hand can always control a saw better than two hands.

[Ill.u.s.tration: _Fig. 20._]

THE STARTING CUT.--In order to make our understanding of the starting cut more explicit, we refer to Fig. 20, in which the thumb of the left hand is shown in the position of a guide--the end of the thumb being held up a sufficient distance to clear the teeth. In this position you need not fear that the teeth of the saw (A) will ride up over the thumb if you have a firm grasp of the saw handle.

The first stroke should be upwardly, not downwardly. While in the act of drawing up the saw you can judge whether the saw blade is held by the thumb gage in the proper position to cut along the mark, and when the saw moves downwardly for the first cut, you may be a.s.sured that the cut is accurate, or at the right place, and the thumb should be kept in its position until two or three cuts are made, and the work is then fairly started.

[Ill.u.s.tration: _Fig. 21. Wrong sawing angle._]

FOR CROSS-CUTTING.--For ordinary cross-cutting the angle of the saw should be at 45 degrees. For ripping, the best results are found at less than 45 degrees, but you should avoid flattening down the angle. An incorrect as well as a correct angle are shown in Figs. 21 and 22.

FORCING A SAW.--Forcing a saw through the wood means a crooked kerf. The more nearly the saw is held at right angles to a board, the greater is the force which must be applied to it by the hand to cause it to bite into the wood; and, on the other hand, if the saw is laid down too far, as shown in the incorrect way, it is a very difficult matter to follow the working line. Furthermore, it is a hard matter to control the saw so that it will cut squarely along the board, particularly when ripping.

The eye must be the only guide in the disposition of the saw. Some boys make the saw run in one direction, and others cause it to lean the opposite way. After you have had some experience and know which way you lean, correct your habits by disposing the saw in the opposite direction.

[Ill.u.s.tration: _Fig. 22. Right sawing angle._]

THE STROKE.--Make a long stroke, using the full blade of the saw. Don't acquire the "jerky" style of sawing. If the handle is held loosely, and the saw is at the proper angle, the weight of the saw, together with the placement of the handle on the saw blade, will be found sufficient to make the requisite cut at each stroke.

You will notice that the handle of every saw is mounted nearest the back edge. (See Fig. 23.) The reason for so mounting it is, that as the cutting stroke is downward, the line of thrust is above the tooth line, and as this line is at an angle to the line of thrust, the tendency is to cause the saw teeth to dig into the wood.