We are talking about one of the most popular materials and the first step that a novice welder must take, therefore, is to learn the correct welding method.
The first objects made of iron date back to over four thousand years ago, and this demonstrates the importance that this material has had in the history and development of civilization. The use of iron is widespread even today for the creation of various objects, from tools to furnishings and artistic creations.
Learning to weld iron in order to obtain perfect joints with high durability, therefore, is a fundamental step for all those who have chosen the blacksmith profession, for DIY enthusiasts and for those who are used to personally providing small home maintenance jobs.
The welding of iron, therefore, is the first procedure that a beginner must be able to master, not only for the fundamental importance of this metal, but above all because the equipment required is of the basic type as it uses the traditional process based on the use of coated electrodes and any filler rods.
From this point of view, therefore, MMA coated electrode welding systems compete greatly with those intended for more modern welding processes, above all thanks to their low cost; the only exception is represented by the TIG welders sold online which, thanks to their versatility in welding different types of metal alloys, have a similar number of requests if not even higher than that of MMA welders, in spite of the higher price.
Cleaning the metal
The first thing to do when preparing to weld the iron, to ensure a quality, homogeneous and long-lasting joint is to prepare the pieces to be welded by subjecting them to a thorough cleaning.
Unlike steel and aluminum, in fact, iron is much more subject to rapid oxidation; the surfaces of the iron sheets and profiles tend to rust very quickly and with a greater degree of penetration. It is useless to remember that if the rust particles end up in the weld pool, they irreparably compromise the seal of the joint, making it weaker and subject to breakage the easier the greater the stresses it is subjected to.
Before welding the pieces, therefore, these must be properly cleaned in order to remove both the surface layer of dirt and rust and the oxide particles that have managed to penetrate deeper into the material; to obtain adequate and effective cleaning, the use of sandpaper, brass brushes or other types of abrasives is required.
If the surfaces to be welded are small then cleaning can be carried out manually, but always scrupulously; for larger surfaces, on the other hand, it is advisable to use multifunctional power tools or sanders, in order to speed up the process and make it more effective.
Once you have made sure that you have removed all visible particles of rust, dirt and other foreign particles from the areas to be welded, it is a good idea to complete the work by “washing” them with acetone or with a specific product for cleaning the components. electronic.
These substances, in fact, have a low acidity content and are able to dissolve all the particles of oxide and dirt invisible to the naked eye, which may have remained on the surfaces to be welded. Once the washing has been carried out, of course, the areas must be carefully dried in order to remove any residues of the substances used.
Mastering the movements
The edge of the pieces to be welded together, in addition to being well cleaned, must also be rounded or angled, depending on the type of joint to be made; the pieces, then, must be juxtaposed together and firmly locked in position with clamps, in order to make them fit together perfectly.
This step is very important as it serves to ensure continuity and linearity to the joint, and also to avoid the formation of “beads” on the weld bead; in fact, the beads are nothing more than drops of molten metal that are formed when the electrode is moved in an imprecise way or at an inconstant speed.
Apart from the obvious imperfection that derives from it, since they make the junction point immediately visible, the beads also represent a risk factor as they create irregular points where dirt and water, or particles of humidity, tend to accumulate extremely ease favoring the subsequent oxidation of the joint.
Another risk that derives from an improper movement of the electrode during the welding process, especially on thin sheets, is that of puncturing the material, ruining the welded pieces and making the work done up to that point in vain.
Before devoting oneself to jobs of a certain importance, therefore, it is good to practice a lot on pieces of sheet metal and recovery profiles, in order to acquire the right dexterity and mastery in the use of the equipment.
Choose the right electrodes
The choice of the type of electrode to use is another fundamental point for learning how to weld iron correctly. The electrode is a metal rod that is melted during welding, thus bringing material to the joint; this rod has various types of coating that have different effects, therefore the type to be used varies both according to the type of welding and the intensity of current required to perform it.
On the market there are welding electrodes that differ both according to the diameter of the metal core and the type of substances used in the coating. Cellulosic electrodes for example, which are characterized by a coating of organic material, are more suitable for welds that require high arc voltages and a high degree of penetration; moreover, the position of the pieces to be welded is a further factor that can influence the choice of electrodes.
Overhead welds, for example, are those where the pieces to be welded are higher than the welder’s head; in this case, usually, electrodes with basic coating are used as they are able to work with a relatively cold bath.
Before tackling an electrode welding, therefore, and in order to obtain the best results, it is necessary to adequately read up on the various types of coated electrodes and their specific applications.