Properly inspected welding equipment is important for safety, performance

Even with the best training, you can't weld properly with poor equipment

Toby Chess ABRN collision repair auto body repair welding inspections welding equiment During the past four and a half years, I've conducted more than 2,900 I-CAR MIG Qualification Tests. While traveling from one collision repair facility to another, I've observed that many shops are woefully lacking in welding knowledge – especially when it comes to maintaining welding equipment.

I've noted that most welders in these shops are in poor condition. This poor condition contributes to poor work, something no shop should permit.

To help get shops up to speed, I put together an in-house welding program that requires them to complete a questionnaire that in turn helps me determine what equipment they already have or might need. I also bring in my own equipment and discuss with owners and managers equipment deficiencies that may exist in their businesses. I-CAR recently has adopted the same program and I recommend it. In the meantime, here are some steps to whip your welding equipment into shape today.

Step 1: Check the condition of your gauges. I often observe that the flow rate and volume gauges are not functioning. The covers usually are missing and the needles are bent or missing. To perform a proper weld, the flow rate for Argon/CO2 gas should be set between 15-25 CFH. If you can't tell what the rate is, your work is going to suffer and you're probably going to waste gas.

If it's time to invest in new gauges, don't be cheap. Shop around and invest in a quality gauge that can provide long-term usage. I've stuck to a model that has proven its worth to me. In five years, I've only had two problems, one of which was repaired under warranty.

Step 2: Replace or repair your MIG guns. Most of the MIG guns I've inspected are in poor condition. Frequently, the neck and trigger areas are wrapped in tape and in need of repair. This kind of damage is created by technicians who bang the gun against a hard surface to clear the nozzle instead of using a proper tool for this chore – MIG pliers.

To remedy this situation, first, repair your existing guns. Second, train your techs to use these pliers. Note that along with allowing you to clean the nozzle (for proper gas flow), the pliers have other uses. They can tighten all parts on the gun and cut wire. They also can remove the nozzle, which can get extremely hot during a weld.

Step 3: Replace worn nozzles. Think of nozzles as consumable items because they wear out. When worn, they must be replaced since they create porosity in the weld. Porosity is the result of oxygen and water that had been trapped in the metal being released in the weld during the welding process. The oxygen and water had been trapped because there was insufficient time to escape prior to solidification of the weld. Porosity is a problem since it produces a weakened weld that can fail when placed under stress.

When looking for wear on a nozzle, search for curling. The curling restricts the amount of shielding gas to the weld, which in turn, leads to increased porosity. Also look for need nozzles whose ends have worn away. In these cases, a hole can open on the nozzle lip. As the gas passes over the hole, water and oxygen are sucked into the weld, again, creating porosity. In both cases, you'll want to replace the nozzle immediately.

Step 4: Check roller tension. Another problem I've frequently found during inspections is incorrect tension on the drive rollers. The wrong tension can lead to bird nesting – wire jambs in the rollers.

To check tension, put the wire between your fingers; adjust the tension until the wire feed stops slipping. Check the tension on a spool of wire. When you lift off the trigger, wire should stop cleanly without unraveling.

Note that bird nesting also may be the result of a nicked or clogged gun liner. Part of proper welding machine maintenance is to take off the gun and blow air through the liner. You should set a regular maintenance schedule for that chore with the other steps I've listed. Maintaining this schedule will prove as valuable as sticking to a regular training plan.