Welding Machines

/There are many kinds of welding machines on the modern market, some of which are designed for heavy-duty commercial use and others which are suitable for home handymen as well as professional users. A welding machine is a device that allows the user to fuse two or more pieces of metal together into a single, solid continuum, giving the whole piece more strength and durability than would be the case were it simply bolted together. Welding allows the combination of several pieces of metal into a single, continuous complex shape that could not otherwise be molded or machined, and makes metal objects and structures less likely to break or fall apart while being used.

Many of the most effective welding machines are arc welders, which make use of a combination of electricity, an inert gas shield, and often, some kind of filler metal to fuse pieces of metal together into a whole. Manual metal arc welding (MMA), metal inert gas welding (MIG), and tungsten inert gas welding (TIG) are all examples of arc welding types that are offered by various welding machines.

welding machines vary in size, including fixed installations in factories, large wheeled models that are too heavy to be practically carried and must be used at places where they can be wheeled to, and smaller compact models that are man-portable with a shoulder strap and can be carried to any place that a human can walk, climb, or crawl. Even the smallest modern models offer many features and settings, such as digital controls to maintain a stable arc, wide volt ranges so that they can be used effectively on different projects and materials, and a large array of safety features.

MMA welding machines

Manual metal arc welding machines, otherwise known as stick welding, are welding machines that operate by using a consumable metal rod, or “stick,” as the electrode – hence the name “stick welding.” The electrode therefore steadily heats and melts and its own tip with the electric arc, and is consumed as it works. The principle bears some resemblance to a hot glue gun, where a stick of hard glue is inserted into the gun and slowly moved forward by trigger pulls as a heated nozzle melts it at the front.  MMA welding is slow because unless the job is very small, the rod must be replaced many times before the job is completed.

Like all arc welding, the MMA welding machine needs a ‘gas shield’ around the welding point to keep the air from oxidizing the molten metal before it can cool and harden. If this were to occur, rust or oxidation would weaken the welding bond to the point of uselessness. An MMA welding machine does not make use of a separate bottle of gas to provide the “shielding gas” that displaces air away from the weld site, however. Instead, there is a thick coating of flux on the consumable rod/electrode, which vaporizes into carbon dioxide in the welding arc’s intense heat and provides the necessary gas shield. The flux leaves a large amount of residue, or slag, on the welded surface, however, meaning that it is impossible to weld electronics in this way.

MIG and TIG welding machines

MIG, or Metal Inert Gas, and TIG, or Tungsten Inert Gas welding machines are continuous use welders, unlike the MMA with its ‘stick welding.’ MIG welding machines include a huge spool of electrode wire, which is continuously fed along a hose by rollers as it is consumed as the filler metal. A tank of argon gas (or a mix of argon and helium for some applications) is also found in the main body of the MIG welding machine, and is pumped along the same hose that houses the charged electrode wire, flowing out around it to provide a shield from the oxidizing air. A MIG welding machine is easy to use and very quick, but does not weld thick materials and produces weaker welds than the TIG machine. It also produces some slag, although not as much as the MMA machine.

The TIG welding machine uses a permanent, non-consumable electrode and a separate source of filler metal. This welding machine requires a skilled operator, but produces very strong welds, as well as being able to weld any kind of weldable metal with a few adjustments.