PORTABLE HAND TOOLS

In addition to using power shop tools, you will be required to operate different types of portable hand tools in the field. You therefore need to understand the safety precautions associated with these.

Figure 3-14.-Shaper table showing straightedge fence and guard.

Portable Electric Circular Saw

The portable electric circular saw is used chiefly as a great labor-saving device in sawing wood framing members on the job. The size of a circular saw is determined by the diameter of the largest blade it can use. The most commonly used circular saws are the 7 1/4- and 8 1/4-inch saws. There are two different types of electric saws, as shown in figure 3-15: the side-drive (view A) and the

Figure 3-15.-Side-drive (view A) and worm-drive (view B) circular saws

worm-drive (view B). Circular saws can use many different types of cutting blades, some of which are shown in figure 3-16.

COMBINATION CROSSCUT AND RIP BLADES.- Combination blades are all-purpose blades for cutting thick and thin hardwoods and softwoods, both with or across the grain. They can also be used to cut plywood and hardboard. CROSSCUT BLADES.- Crosscut blades have fine teeth that cut smoothly across the grain of both hardwood and softwood. These blades can be used for plywood, veneers, and hardboard.

RIP BLADES.- Rip blades have bigger teeth than combination blades, and should be used only to cut with the grain. A rip fence or guide will help you make an accurate cut with this type of blade.

HOLLOW-GROUND BLADES.- Hollowground blades have no set. They make the smoothest cuts on thick or thin stock. Wood cut with these blades requires little or no sanding.

Figure 3-16.-Circular saw blades.

ABRASIVE BLADES.- Abrasive blades are used for cutting metal, masonry, and plastics. These blades are particularly useful for scoring bricks so they can be easily split.

Figure 3-17 shows how versatile the circular saw can be. To make an accurate ripping cut (view A), the

Figure 3-17.-Different ways to use a circular saw.

ripping guide is set a distance away from the saw equal to the width of the strip to be ripped off. It is then placed against the edge of the piece as a guide for the saw. To make a bevel angle cut up to 45 (view B), you just set the bevel adjustment knob to the angle you want and cut down the line. To make a pocket cut (views C and D), a square cut in the middle of a piece of material, you retract the guard back and tilt the saw so that it rests on the front of the base. Then, lowering the rear of the saw into the material, hold it there until it goes all the way through the wood. Then, follow your line.

Observe the following safety precautions when operating a circular saw:

Don't force the saw through heavy cutting stock. If you do, you may overload the motor and damage it.

Before using the saw, carefully examine the material to be cut and free it of nails or other metal objects. Cutting into or through knots should be avoided, if possible.

Disconnect the saw from its power source before making any adjustments or repairs to the saw. This includes changing the blade. Make sure all circular saws are equipped with guards that automatically y adjust themselves to the work when in use so that none of the teeth protrude above the work. Adjust the guard over the blade so that it slides out of its recess

Figure 3-18.-Saber saw.

and covers the blade to the depth of the teeth when you lift the saw off the work.

Wear goggles or face shields while using the saw and while cleaning up debris afterward.

Grasp the saw with both hands and hold it firmly against the work. Take care to prevent the saw from breaking away from the work and thereby causing injury.

Inspect the blade at frequent intervals and always after it has locked, pinched, or burned the work. Disconnect the saw from the power source before performing this inspection.

Inspect daily the electric cords that you use for cuts or breaks. Before cutting boards, make sure the cord is not in the way of the blade. Saber Saw

The saber saw (figure 3-18) is a power-driven jigsaw that cuts smooth and decorative curves in wood and light metal. Most saber saws are light-duty machines and not designed for extremely fast cutting. There are several different, easily interchangeable blades (figure 3-19) designed to operate in the saber saw. Some blades are designed for cutting wood and some for cutting metal.

The best way to learn how to handle this type of tool is to use it. Before trying to do a finished job with the saber saw, clamp down a piece of scrap plywood and draw some curved as well as straight lines to follow. You will develop your own way of

Figure 3-19.-Saber saw blades.

gripping the tool, which will be affected somewhat by the particular tool you are using. On some tools, for example, you will find guiding easier if you apply some downward pressure on the tool as you move it forward. If you don't use a firm grip, the tool will tend to vibrate excessively and roughen the cut. Do not force the cutting faster than the design of the blade allows or you will break the blade.

You can make a pocket cut with a saber saw just like you can with a circular saw, although you need to drill a starter hole to begin work. A saber saw can also make bevel-angle and curve cuts.

Observe the following safety precautions when operating the saber saw:

Before working with the saber saw, be sure to remove your rings, watches, bracelets, and other jewelry.

If you are wearing long sleeves, roll them up. Be sure the saber saw is properly grounded. Use the proper saw blade for the work to be done, and ensure the blade is securely locked in place.

Be sure the material to be cut is free of any obstructions.

Keep your full attention focused on the work being performed.

Grip the handle of the saw firmly. Control the forward and turning movements with your free hand on the front guide.

To start a cut, place the forward edge of the saw base on the edge of the material being worked, start the motor, and move the blade into the material.

Portable Reciprocating Saw

The portable reciprocating saw (saw-all) (figure 3-20) is a heavy-duty power tool that you can use for a variety of woodworking maintenance work, remodeling, and roughing-in jobs. You can use it to cut rectangular openings, curved openings, along straight or curved lines, and flush.

Blades for reciprocating saws are made in a great variety of sizes and shapes. They vary in length from 2 1/2 to 12 inches and are made of high-speed steel or carbon steel. They have cutting edges similar to those shown in figure 3-19.

Figure 3-20.-Reciprocating saw.

Before operating this saw, be sure you are using a blade that is right for the job. The manufacturer's instruction manual shows the proper saw blade to use for a particular material. The blade must be pushed securely into the opening provided. Rock it slightly to ensure a correct fit, then tighten the setscrew.

To start a cut, place the saw blade near the material to be cut. Then, start the motor and move the blade into the material. Keep the cutting pressure constant, but do not overload the saw motor. Never reach underneath the material being cut.

Observe the following safety precautions when operating a reciprocating saw:

9 Disconnect the saw when changing blades or making adjustments.

Figure 3-2l.-Portable router with edge guide.

Place the foot of the saw firmly on the stock before starting to cut.

Don't cut curves shaper than the blade can handle.

When cutting through a wall, make sure you don't cut electrical wires.

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