There are many things to consider when selecting the right welding process for the job. In most cases equipment is the limiting factor. Many times in the field you may only have a Stick welder, this limits you to one process. When it comes down to having all the right equipment at your disposal there are a few questions you must ask yourself. What kind of oxide layer, rust, paint, etc. does the material have on it? What size weld is required? What is the thickness and type of material being welded? How skilled is the operator? All these questions will lead you to the right process.
GMAW or FCAW can be grouped together for this instance. When using a wire fed process, the required skill level is at its lowest. This means with minimal experience a sound weld could still be produced. These processes also have the highest deposition rates. What does this mean? With high depositions, larger welds can be produced faster, the faster the welds are produced the lower the heat input. Where the processes usually fail is material cleanliness. With a DC reverse polarity there is no cleaning action, leaving those hydrocarbons (paint, oil, etc.) within the weld as porosity or voids. Although with the right amount of silicon (an arc stabilizer) you will be able to weld through thicker mill scales. Also reliable equipment can be very costly (between $3000-7000).
SMAW is usually the lowest equipment cost option. Don’t be fooled by the cost of the equipment as the stick welding process is one of the slowest processes available, and requires a medium skill level to produce sound welds. The best thing about stick welding is when choosing the correct rod (xx11) the arc stabilizers will allow you to weld through rust and paint with ease on AC. Another great advantage to stick welding is it requires no shielding gas, making it the ideal option for outdoor welding. However the biggest downfall is the high heat input from the low travel speeds required, this limits the thickness of materials that are weldable (Generally 1/8″ minimum). Also a small variety of materials can be welded with the SMAW process.
GTAW is the highest equipment cost option, the lowest price for a fully capable unit (AC/DC, with hi frequency start) is around $2000 and units with the best options are in the $5000-12000 range. GTAW also requires the most skill, in most cases there are three operations to keep track of at once (foot pedal, torch, filler wire). Where GTAW shines is precision, and versatility, very small and precise welds can be made with ease on a variety of clean materials. In X-ray or UT tested joints, GTAW can produce sound welds time after time with a skilled operator.
Once you have determined which weld process will fit the work you need done, go to Baker's Gas for all of your welding supplies. Whether you need a new welder, wire, electrodes, tungsten, or safety equipment, they can get it to you at a great price!