Whatever your project – whether mending a metal fence or repairing teeth on a backhoe bucket, the following advanced welding tips will help you get the job done faster, and with less waste and effort.
1. Make Good Use of Magnets
Choose from a wide range of specialized magnets or clamps to use as “third hands.” These can securely hold welding tabs, brackets or gussets to the workpiece, lids on a box, or corners perpendicular during the welding process. Use an adjustable welding table to support smaller items. Don’t remove magnets until the weld has completely cooled, so that the hot metal doesn’t shrink and ruin the alignment.
2. Welding Out of Position
If you can’t fix your workpiece in a comfortable, flat welding position using magnets and clamps, it’s important to remember that the weld puddle may drip. If welding overhead, move quickly and steadily using a circular motion but keep the puddle narrow. To allow the puddle to cool faster, maintain a lower electrode temperature by reversing polarity, and use less voltage so that the puddle remains small.
3. Completely Clean Out the Area to Be Repaired
Impurities such as oil, grease, dust, and moisture, can cause problems later if they are absorbed into the metal. Clean out the area thoroughly using a sander or wire brush and wipe away any debris. If repairing cracks, grind them out with a grinder before welding. Where the shape and size of the crack make it impossible to reach the bottom, use a slower welding speed, which allows time for impurities, such as hydrogen bubbles, to rise to the surface before they become trapped.
4. Beware of Hydrogen
Hydrogen is the enemy, when it comes to welding. Certain metals, such as high-strength steel, are more susceptible to hydrogen cracking, which may occur long after the weld is completed. Welding thick or highly restrained pieces can also cause cracking. Before welding, seek and destroy any alien material, such as paint, dust, or grease. Then preheat the metal before, during, and even after welding for a few hours. This slows down the cooling time so that more hydrogen can escape before the metal solidifies.
5. Bead-Laying Tips
With stick welding, it’s important to run a straight bead by keeping an even travel speed – and maintain the angle of the rod so that the slag trails behind. When you get to the end of the weld, run the rod back in the other direction an inch or so, in order to prevent a crater developing that could crack later.
6. Choose the Best Electrode for the Job
For general use stick welding, choose a 6011 electrode, but for thinner material, go with a 6013. Rod diameter should be higher for thicker metal and smaller for thinner stock.
In the case of high-carbon or other high-alloy steels that are harder to weld, it’s important to use low-hydrogen electrodes. Be sure to leave them in the package until the last minute, to expose them to air for as short a time as possible.
7. Be Aware of Aluminum Welding Differences
When welding aluminum, different materials and techniques are required. Aluminum should be welded with either a TIG or MIG process. Before welding, remove oxides from the aluminum surface using a stainless steel brush and solvents. These oxides have a very high melting temperature, which can inhibit the filler from welding with the metal. Use only argon-helium or argon gas to shield the weld. Preheat the area, but don’t overheat, which could cause burn-through. At the end of the weld, don’t leave a crater, which will inevitably lead to cracking. Instead back weld for an inch or so.
For all your welding supplies, including tools, consumables, and accessories, visit Industrial Metal Supply.