How To Weld ... Learn How to Weld By Welding!

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Of course, while you're doing your best to control the rate of travel, another complication is taking place: Your welding rod is melting, and as a result, the length of your arc is getting longer. So while you're pulling the electrode toward you, you must also push the tip gradually downward to compensate for the rod's ever-decreasing length. As a general rule of thumb, try to keep arc distance equal to the diameter of the electrode being used. When the gap is correct, you'll hear a crackling sound . . . but when the arc is too long, you'll hear a hollow, blowing noise. So try to develop an ear, as well as an eye and a feel, for arc length.

Once you've completed a pass, let the fresh weld cool from red-hot to black, then use a chipping hammer to knock off the thin outer crust of slag. Underneath will be . . well, anything from a disappointing mass of pits and bubbles to an attractive, evenly distributed, deep, strong weld. The ideal bead is about 1-1/2 to 2 times as wide as the diameter of the electrode, and as long as the amount of rod used.

You can't expect to get a perfect specimen until you've had quite a bit of practice . . . so keep at it, experiment with amp settings and arc distances and travel speed—try your hand at moving the electrode from side to side in a tight zigzag or circular motion, too—and analyze each bead's appearance. Make an honest effort to be your own worst critic, and you'll be able to detect what you're doing wrong and correct it. Here are some things to look for:

Slag pockets: black, nonmetallic deposits in the weld. Try keeping the electrode movement steady . . . and hold the rod at an angle closer to perpendicular.

Undercutting: a shallow groove along one or both sides of a weld. This usually results from moving the electrode too fast. Slow down a little.

Spatter: droplets of metal around the weld. It isn't a serious problem, but—if adjusting amperage doesn't cure it—you may be holding the electrode too high.

Exercise No. 2: A Butt Weld

Now that you're running beautiful welds consistently (well, almost), you're ready to start actually joining two pieces of metal. Again, we'll use 1/4" steel (be sure the edges to be fused are square) and 1/8" rod. If you happen to have two pieces that are more than 1/4" thick, bevel the top edges to about 45° to assure a deep, penetrating bond.

In any case, position the two sides so that they almost, but don't quite, touch (to allow for expansion) . . . and clamp them down securely. Because of the tremendous heat applied during welding-and the stresses created by the variations in temperature along the seam as the work progresses and later cools—the fresh weld and any adjacent metal are subject to distortion, possibly causing the joint to twist and crack the electrode material. Clamping the pieces is the easiest way to minimize the effects of these forces, though a "tack" weld-just a good, penetrating 1/4" dot of metal—placed at both ends of the joint, and used in addition to the clamps, will assure a positive bond.

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