Hobart Welder Troubleshooting

G.K. Bayne

Hobart welders are for the most part very reliable machines. There are three different types of Hobart welders, a stick welder, a wire feed unit and a TIG machine. The stick welder uses a welding electrode rod that melts when electrically energized. The wire feed welder feeds a single wire from a spool. The TIG (tungsten inert gas) welder produces an electrical arc that melts a separately hand fed welding rod. All of these welders use electrical power fed from a main electrical panel.

Electrical Connections

All welders need a constant electrical supply. In some cases, the electrical supply will be either 220 VAC single phase or a 480 VAC three phase power. The connections and the wires that feed the power to the welders must be properly sized. Too small of wires and connection points can lead to an erratic operation of the welder. This erratic operation leads to welds that are non uniform and inconsistent. Over time, wire that is too small to carry the electric current can become brittle and corrode or break. This too will lead to erratic operation of the welder. The connections themselves can become corroded if the welder is operated in a moist to wet environment. Attention must be paid to check all electrical connections on a regular basis and clean the connectors when signs of corrosion appear.

Wire Feed Welders

The wire feed type of Hobart welders uses a wire spool to feed material into the weld area. The wire is pushed through a plastic tube that resides inside the power and gas hose. The wire is then forced through the end of a welding gun. Over time, the plastic tube can become worn from the wire rubbing against the plastic liner causing the wire to stick and not properly feed. The gear motor that pushes the wire through the assembly can also pinch the wire for an improper feeding speed. A special inert gas is also fed into the weld area. The plastic tube that feeds the gas can also become brittle and break. This leads to an improper amount of gas being fed to the welding process. The gas aids in reducing welding splatter and creates a smooth weld when the proper flow is achieved.

TIG Welders

TIG welders are specialty machines used for welding difficult metals, such as aluminum. A very intense electrical arc is formed at the end of a hand held torch. The electrical arc then melts the metal to form the weld. A filler rod is held by hand and fed into the welding area. Just like the wire feed welder, a special gas is blown into the weld area to keep out and impurities. A broken gas hose can cause a weld to blacken or form an erratic molten metal puddle area. In order to keep the torch cool to the hand touch, a small pump pushes water through the torches head and the long hose. Failure of the water-cooling system will cause the torch handle to overheat. Residing within the welder unit itself is a set of special arc gaps. Theses gaps must be kept cleaned and kept at a preset distance. Failure to keep these arc gaps cleaned and set properly will cause the hand held torch to fail during the welding process. The tungsten rod must also be kept cleaned and in the shape of a sharp point. The tungsten rod keeps the intensity of the welding arc to a high temperature in order to melt the metal being welded.