Making Use of Portable Welders

welding is perhaps the strongest method of fastening two pieces of similar metal together, since it actually melts part of their substance and allows it to mix together, hardening into a single piece. Bolting, soldering, riveting, and all the other methods do not make a bond as intensive or thorough as a deep weld will. Furthermore, only a well-made weld will actually seal the edge between two pieces of metal – which is why welding is used for fuel tanks or other liquid-holding containers.

welding requires that both metals that are to be joined are the same – stainless steel is welded to stainless steel, aluminum to aluminum, and so forth. This is not some mysterious byproduct of alchemy, comprehensible only by the initiated – in fact, the reason is very simple and practical. Metals all melt at different temperatures, and since both pieces of base metal must be rendered molten at the edge for welding to occur, there is no one temperature that will cause both to be ready for welding at the same time. Either one will still be solid, or one will be boiling away in vapor, depending on the temperature the welder opts for.

The only type of welding that can be used to bond two kinds of different metals are braze welds, which make use of bronze or some other high-adhesion filler metal in what amounts to an advanced type of soldering (with a few extra features that create a better, stronger bond). These welds are used whenever joining dissimilar metals becomes a necessity, or for certain low melting point metals such as copper and some pot metals when being joined to a workpiece of the same metal.

Both standard welding and braze welding can be accomplished in a shop, or they can be carried out using a portable welder. portable welders have many advantages, and a few disadvantages. The advantages of portable welders include –

•    Portability is the most obvious benefit of using a portable welder. Small models that weigh twenty or thirty pounds and can be carried with a sturdy, suitcase-like handle or slung over the back make it possible to bring welding to nearly any place where a power supply can also be furnished. Small, lightweight generators help make the process feasible, although there are limits to the power that these generators can supply.

•    Oxyacetylene torches are perhaps the ultimate in welding portability, since they can be broken down into their components – an oxygen cylinder, an acetylene (or other fuel gas) cylinder, a hose, and a welding or cutting torch – and then assembled and used. The other advantages of gas welding include that it needs no power supply beyond what is furnished by the vapors in its tanks, and that gas torches are flexible enough to weld, cut, braze, and solder, depending on the torch tip that is used.

•    Larger portable welders, which move on wheels or can be placed onto dollies or trailers with relative ease, are still more flexible than those that cannot be moved readily from the workshop. All kinds of portable welders are highly useful for those who often need to do welding outdoors, such as people working at construction sites or building rugged metal fences, animal pens, and metal barns or sheds on the farm.