Some Useful Shop Techniques

The leader in a wood working project needs to be able to explain to children the various techniques that will be called for in making these simple projects—such matters as how to enlarge or reduce a pattern, how to trace it properly, how to handle a coping saw or a jigsaw, how to shape and sand the article, how to put its parts together, and what to use in painting and finishing the project.

Checkerboard Method Of Enlarging Patterns

The design for any of the following projects may be enlarged to any desired proportion by placing a piece of tracing paper which has been ruled with ½-inch squares over the pattern and tracing the outline. A second piece of tracing paper is then prepared with larger squares to give the desired increase in size. For example, 1-inch squares will double the size of the pattern—¾ -inch squares will increase the size of the pattern by one third, and so on. The outline of the pattern is then transferred to the second sheet by copying the traced outline, one square at a time.

Preparation Of Materials

If the children are expected to trace the patterns themselves, care should be taken that the tracing paper is held securely to the book and to the piece of wood to which the pattern is being transferred. This may be accomplished by pushing the edge of the tracing paper firmly into the binding of the book or using clips or cellophane tape to hold the tracing in place. If a soft-lead pencil is used to prepare the tracing, the pattern may be transferred by simply turning the paper over and rubbing the back of the page with a blunt stylus or pencil point wherever the lines appear.

Shop Techniques Checkerboard Method For Enlarging A Pattern

Lay tracing paper over the design or pattern you wish to enlarge and outline it carefully.

Draw a perfect square around the traced pattern and, with the aid of a ruler, divide this box into any convenient number of small squares.

Decide what size the pattern should be and draw a second square box of this dimension. Divide the large box into exactly the same number of squares used in marking off the original tracing.

Now you are ready to copy the pattern in the large box, sketching one square at a time until the drawing is complete.

This same technique may be used to reduce the size of a pattern, if the box in which the pattern is copied is made smaller than the original design.

Considerable time and trouble may be saved by preparing, in advance, patterns for each of the component pieces of the project to be attempted. This technique is particularly useful when dealing with large groups of children. The outline for each piece of the project is traced on a material such as masonite, thin (8-inch) plywood, or heavy, noncorrugated cardboard, and then cut out. Additional detail which does not appear in the outline form may be added by cutting out certain areas within the pattern to form a stencil. If heavy cardboard is used, the stencil can be prepared with a sharp knife or razor blade.

Blocks of the proper size to fit the pattern for each piece of the project are then cut out from the available wood. A circular power saw equipped with a rip fence is ideally suited to this task. When the patterns haye been traced on the proper-size blocks, each child is provided with a set of blocks bearing an accurate outline of the pieces for his project.

Use Of Coping Saw And Jigsaw

The difficulty which children encounter in using a coping saw efficiently is largely due to inadequate support for the piece of wood to be cut. The wood must be clamped or held in a vise so that the point at which the saw is cutting is as close as possible to the jaws of the vise or the grip of the "C" clamp. If this principle is not observed, the resulting vibration or chattering of the board is likely to cause the wood to split. It may be necessary to change the position of the piece of wood several times during the cutting operation to maintain the proper relationship to the vise' or clamp.

When cutting with a coping saw, best results are achieved by using short, even strokes directed at right angles to the wood. The blade should be guided by slowly turning the frame, avoiding any sudden twisting of the handle which may result in broken blades. Detailed figures with sharp angles should be cut from the wood block in rough outline form before attempting to reach the more difficult corners. Very acute angles can best be cut by approaching the apex from two sides instead of attempting to turn the corner.

The jigsaw may be used safely by the older children if a few simple precautions are observed. The saw should be mounted at a height that will enable the child to have maximum control of the piece of wood he is cutting. The engine belt and pulley must be recessed or enclosed to avoid the danger of catching a finger carelessly thrust into the path of the belt. The proper adjustment of the jigsaw should be stressed so that the piece of wood to be cut is held firmly against the table of the saw, yet does not bind as it is fed into the blade. The most effective working position is attained by standing squarely in front of the jigsaw, fingers resting on top of the board; thumbs pressed against the front edge of the piece of wood. Thus, the fingers hold the board firmly against the table of the saw as the thumbs guide it toward the. blade, taking care that no fingers or thumbs are di rectly in the path of the blade. Children should be cautioned never to force the wood into the saw, and to allow adequate time for turning sharp corners. Sudden twisting or jerking of the piece of wood will inevitably result in broken blades.

When cutting with a coping saw, use short, even strokes, keeping the frame of the saw at right angles to the piece of wood. The working point should be kept close to the jaws of the vise or clamp in which the wood is held.

Before using the jigsaw, it is important to check the adjustment of the "foot." To set the foot, release the thumbscrew, raise the foot, place the piece of wood BEHIND the blade, and let the foot rest on the wood. Then tighten the thumbscrew, and place the wood in front of the blade.

The fingers hold the board firmly against the table of the saw as the thumbs guide the wood toward the blade.

Fairport Public Library 1 Village Landing Fairport, Nx 14450 copy\ Final Shaping And Sanding Of Pieces

Careful sanding and shaping of the component pieces are essential to turning out a truly finished article. Children are so eager to assemble their projects and see them take shape that they often neglect these important steps which determine the quality of their work. When power tools are not available, the final shaping of the pieces may be accomplished with a wood rasp or half-round file. The wood should be clamped in the same manner as described for sawing, with the working point as close as possible to the jaws of the vise or clamp. A guide line will help the child to locate the high points which require trimming. When the desired shape has been attained, the pieces are ready for sanding. Smaller pieces, such as wheels or axles, can be sanded by placing the piece of sandpaper on a work bench, and rubbing the wood against the abrasive side. For the flat surfaces of larger pieces, the sandpaper may be wrapped around a stick of wood or block to make the job easier. A medium-grade sandpaper is adequate for most of the suggested projects and should be dispensed in small pieces for ease of handling.

A disk-type power sander is an extremely useful addition to any workshop. With the aid of a power sander, even the most radical departure from the outline of the pattern may be shaped into some likeness of the figure it was intended to represent. If certain safety measures are observed, the power sander may be used safely by the older children. The operator should always stand to the side of the sander, holding the block of wood to be sanded firmly with two hands. If the sander rotates toward the operator's right, the block should be held against the top half of the disk so that if the wood should slip, there will be less danger of its striking the operator. Additional protection may be provided by requiring children to wear some form of eye shield when using the sander. One should never attempt to reach "inside angles" with a power sander unless there is adequate space to allow for the thickness of the disk between the opposing sides. Failure to observe this rule will result in tearing of the sandpaper disk and marring of the wood.

Assembling The Project

One of the most difficult operations involved in constructing an article of wood is nailing the pieces together correctly. This step should be carefully supervised to insure proper assembly of the project. Children should be taught to hold the hammer near the end of the handle to attain maximum power with each stroke. Nailing should be done on a sturdy work bench or on the floor so that the force of each stroke of the hammer is not dissipated due to inadequate support of the wood. This practice will also serve to reduce the amount of noise produced in this operation.

For the proper placement of nails when fastening a board to the edge of another piece of wood, the following procedure will prove helpful. Mark the nailing surface with a pencil line to indicate the thickness of the piece into which the nails are to be driven. Start the nails into the wood at a point midway between this line and the edge of the board, driving them through to the undersurface of the board.

Then position the pieces carefully and drive the nails all the way in. The hammer should be held near the end of the handle for maximum power and control.

The importance of starting the nail properly should be stressed. When a nail begins to bend, it should be pulled out or straightened before any attempt is made to drive it further into the wood. Bending of the nail can usually be avoided by striking the head of the nail squarely and using short, quick strokes. The proper placement of nails is extremely critical. When one piece of wood is to be nailed to the edge of another, it is helpful to indicate the thickness of the edge by a line drawn on the surface through which the nails are to be started. This enables the child to visualize clearly the limits of the nailing area and to place the nails so that they will hold firmly in the base piece. It is advisable to drive the nails all the way through the wood, allowing them to protrude slightly beyond the under-surface, before positioning the board over the base piece. A vise is often useful in holding the pieces in the proper relationship for nailing. A thin coat of wood glue applied before nailing the pieces together will add greatly to the strength of the joint.

Painting And Finishing The Article

All articles should be protected with some type of finishing coat. A natural finish with shellac or clear lacquer or varnish is adequate for most of the projects in this manual. Spray dispensers can be used effectively. The softer tones with a flat finish are available in rubber base or tempera paints which are water soluble. Enamels are usually less satisfactory because they are difficult for children to work with and require considerable time to dry thoroughly.

Paint should always be dispensed from shallow containers to minimize the hazard of tipping and spilling. Children can be taught to remove the excess paint from the brush by wiping it on the edge of the container each time the brush is dipped into the paint. If the brush is applied lightly to the wood surface in such a way that the strokes are directed away from the operator, preferably in a downward direction, the danger of spattering is reduced. A container of brush cleaner or other solvent should be provided to receive the used brushes.

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