Welder Buyer's Guide - Welder Knowledge

If you watch TV at all, then you know there has been an explosion of specialty programs over the past several years that deal with metal fabrication in some form or another. From a show about a family building choppers-a show that seems to be more about the drama involved with interpersonal relationships than the actual building process-to building lawn mowers out of Mustangs, almost any area of metal fabrication is covered.

The benefit for the racer is that these shows have raised an awareness about welding, and the people who manufacture welding equipment have taken notice. They are making more welders that fit the needs of home-based fabricators. This is a perfect fit with the Saturday night racer. There has never been a time when the technology of welding and the associated products have been more user friendly and available to the public than right now. In the past, the types of welding processes and the materials that we wanted to weld at home were almost the exclusive domain of aerospace companies.

If you have ever entertained the idea of purchasing a welder, now is the time to make it happen. The science of welding is now much easier to accomplish in non-industrial settings than at any other time in the past. The newer machines have features that make controlling the weld and the arc much easier. These products allow people to enjoy the process more because the result is a better weld that is strong and looks good. As an added bonus, the power requirements are not as critical as they have been in the past. Ninety-nine percent of the homes in this country probably have the power required to run a welder that satisfies any of the needs of the Saturday night racer. If your home has an electric clothes dryer or an electric water heater, you probably have enough power to run a TIG or MIG welder that has a newer style.

If you are actively racing, you need a welder to help with preparation of the car. And if you expect to maintain and set up the car and perform race maintenance in a timely fashion, many small repairs that are not practical from a time perspective have to be performed by an outside vendor or specialty welding shop. That can change with a welder and some basic skills. In addition, along with your newly developed welding skills, you may be able to save some money by making some of your own parts.

If you make the decision to purchase a welder, what kind do you need? Remember, there is a difference between need and want. You need to be honest with yourself with regard to the level of skill you are willing to develop. Please remember that better equipment does not negate the need for skill. Even though the welders are much better than in the past, you still need some skill to weld. Prior to discussing price or features, let's spend some time reviewing the welding process. This gives you a better idea of what you need from a welder so that it is suited to your needs and your individual skills. It is all about information and asking the right questions.

There are only two types of welders that should even be considered for race car fabrication. MIG (Metal Inert Gas) and TIG (Tungsten Inert Gas) welders are really the only selections that make sense in today's world. Oxy-Acetylene and Stick or Arc welders are not even valid considerations given the other options available to the racer today.

If we view these two types of welding processes from a philosophical perspective, all that is happening is two pieces of metal are heated to the point of melting in the area to be joined. This molten metal is located in a very small controlled zone. In this zone, a puddle of molten metal is formed and the operator feeds a filler material of metal to this puddle. Depending on the type of weld and the material being welded, this filler metal can be made up of a variety of alloys.

The puddle is pushed or pulled along the area to be welded as the process continues. With both MIG and TIG welding, the puddle is shielded from the ambient environment by a flow of inert gas. This gas can be any variety of inert gases, depending on the process and the material being welded. The gas shield prevents the molten metal from mixing with the oxygen in the air and causing more complex reactions to take place in the molten metal in the puddle. These reactions would weaken the weld or make the weld impossible to complete. The gas shield keeps the welded area free from the oxidation and contamination that would take place if the weld puddle were exposed to the oxygen present in the air.

MIG welding is a much more automated process than TIG welding. With MIG welding, power levels are set prior to starting the welding process. The metal (represented by the "M" in MIG) filler rod is fed automatically through the torch or gun, as it is called. The operator is responsible only for the movement of the gun along the area to be welded.

The gas shield used in MIG welding is usually CO2 or a mixture of CO2 and argon. Again, the selection of the gases used is dependent upon the type of material and the operator's preference. (I prefer a mixture of CO2 and argon.) MIG welding is an easier process than TIG welding. It is easier to gain a level of proficiency quickly with MIG versus TIG welding. The filler rod is fed automatically into the weld puddle, and the rate the rod is fed into the weld can be adjusted, which means that the level of precision required for the fitment of the weld joint is not as critical as with TIG welding. This is not to say that the fitment of the joint is not a critical component to the strength of the weld. The reality of the situation is that the MIG weld allows a different level of tolerance to fitment that is not practical or workable with the TIG process.

As mentioned previously, the "T" in TIG represents tungsten. TIG welders use a sharpened tungsten rod to pass the arc from the torch to the work piece. There is a lot to do while you are TIG welding. It requires both hands, as one hand holds the TIG torch and maintains the tip above the weld puddle, while the other hand feeds the filler rod into the weld puddle. One foot is required to vary the power level via a foot-operated pedal.

There are a multitude of other things happening with the TIG torch while you are welding. Some TIG torches are water cooled and others are gas cooled. If not for this cooling process, the tungsten tip and the torch itself would melt in your hand.

While the right TIG welder gives you the option to weld aluminum and other metals aside from steel, not all TIG welders can weld aluminum. You have to select the right welder for the jobs you are going to do.