Portable Stick Welders – the Basics of SMAW Welding

Stick welding (or SMAW [Shielded Metal Arc welding] as it is now known after the ‘great renaming’ of welding processes which has probably caused more confusion among novices than it has improved the accuracy of welding names, since the new names are needlessly similar to each other in the view of many) is a straightforward welding method which is suitable for portable welding applications in many different circumstances.

It has its limitations – imposed by the inconvenience of the constant changing of sticks, the coating of slag that it leaves behind, and the fact that it cannot be used to effectively weld aluminum. However, it is useful in a wide range of different situations.

One of the biggest advantages to stick/SMAW welding from the viewpoint of a portable welding machine user is that these implements can be used outdoors without difficulty – indeed, some variants of the stick welder have been made which are capable of welding underwater. The reason why stick welders are so suitable for outdoor welding is that the welding stick or rod – which doubles as the electrode for the arc welding process – is coated in a thick layer of flux.

This flux vaporizes as the welding process continues, thus creating a cloud of shielding gas that is intimately close to the point of action. The gas created in this way shields the molten metal of the weld pool even in a strong wind – meaning that only a true gale is enough to expose the weld pool and cause a possibility of oxidation. Stick/SMAW welders are therefore used for outdoor fabrication and repair of all kinds, and are useful to the portable welding enthusiast for this reason.

Like all arc welders, the stick/SMAW welder operates by passing a powerful electric current from the electrode of a welding gun into the base metal. The electrode is not kept in contact with the metal after an initial “strike” is made to complete the current through the workpiece. Instead, it is slightly withdrawn so that the electrical arc passes through the air for a short distance before entering the base metal. The resistance of the air to electric current is such that much of the electricity is converted into heat energy, producing temperatures as high as 11,000˚ Fahrenheit at the point of welding. Much less of this heat actually enters the metal, but it is sufficient to melt it.

In a stick/SMAW welder, the electrode – through which the electricity is passed before “jumping” across the narrow air gap to the workpiece – is also the supply of both the filler metal (which adds to the welding pool created by the melting of the two pieces of base metal along the welding path) and the shielding gas that keeps the weld from oxidizing.

At the extreme temperatures of the weld, most metals oxidize in an instant if they are exposed to oxygen, resulting in brownish welds that may be weak, riddled with Swiss-cheese-like holes, or otherwise flawed, enfeebled, or damaged. Therefore, a shielding gas must be constantly blown over the welding point to force oxygen away from the area. In the case of a stick welder, a flux coating on the outside of the “stick” vaporizes during welding, thus producing the needed gas shield without the need for a separate tank of shielding gas. The electrode simultaneously melts to provide filler metal, thus combining several vital functions into one and giving the SMAW welder its distinctive benefits.