Tool School: Stud Finder, Circular Saw, Voltage Tester
Stud Finders have changed. Whether you are hanging pictures, putting up a new set of shelves or getting ready to start an addition, knowing where the framing is located is important. Before stud finders, a nail had to be driven into the wall or ceiling, until impacting a solid object beneath the wallboard. You may also have used a stud finder that utilized a magnet to find nails and thus, a framing member. Punching holes is messy and magnetic detection is slow and unreliable because nails are often spaced 12 inches apart – no nail, no stud. Electronic stud finders have changed all that. They give you an amazingly accurate view into the wall and show you exactly where each stud or joist is located. In a way, these stud finders are like a touch switch on a touch-sensitive lamp. They are using changes in capacitance to sense where the stud is. In other words, modern stud finders find the actual stud or joist and not just the nails.
Circular Saw is a portable electric cutting tool that houses a thin, round blade that rotates at high speed. A circular saw can be used to cut wood, metal, plaster and other materials depending on the type of blade. Better circular saws are very powerful and have two handles, which are used to guide the saw in the direction of the cut. The blade protrudes below the saw’s flat base (known as the saw table) and the saw table can be adjusted to alter the blade’s depth and its miter angle. A spring mounted guard helps to protect the operator from coming into contact with the blade. As the saw makes its way through a long cut the blade can bind thrusting the saw backward. This can be dangerous – especially when standing behind the saw. We remain safe at all times because we position our body to one side of the saw – never behind it. Also, we always set the blade depth to match the thickness of the material being cut. This keeps all of the teeth in the cutting area at all times, thus, reducing backlash and making it easier for the saw to make its cut.
A Voltage Tester measures the flow of current in an electric circuit. The simplest tester consists of a small neon bulb with two insulated wires attached to the bottom of the bulb housing – each terminating at an insulated metal probe. This type of tester is only used with the current turned on (again, to determine current flow through wires or a receptacle). Better units are also used to measure actual voltage. In either case look for a tester rated for up to 500 volts.
To use a voltage tester simply touch one probe to one wire or connection, and touch the other probe to the opposite wire or connection. If the wires or component are receiving electricity, the light in the housing will glow. If the light doesn’t glow, the trouble is at the point tested. For example, if you suspect an electrical outlet is faulty, insert one probe of the tester into one slot in the outlet and the other probe into the other slot. The light in the tester should light. If it doesn’t, the outlet may be bad.
To further test the outlet, pull it out of the wall. Place one probe of the tester on one terminal screw connection and the other probe on the other terminal screw. If the tester bulb lights, you know the outlet is malfunctioning — there is current flowing to the outlet, but it isn’t flowing through the outlet to provide power to the appliance plugged into it. If the test bulb doesn’t light, there is no current coming into the outlet. The problem may be a blown fuse or tripped circuit breaker, or the wire may be disconnected or broken behind the outlet.
CAUTION: When working on electrical circuitry there is the chance of electric shock. Never touch bare electric wires or bare test probes and never work on electrical wiring while in a damp area or on a wet floor.