As always we make a brief introduction, welding is a thermal fusion process and as such it unites and incorporates materials that have compatible chemical and mechanical characteristics.
Welding means joining, and joining determines a strong cohesion of the two elements that are part of it.
They are trivialities, we realize it, but from daily life we have learned that it is precisely on trivialities that the most sensational mistakes are often made.
So how to avoid committing them, or at least, reduce the risk margin that a weld is not strong enough?
First of all it is necessary to choose the correct material and on this we invite you to follow all the news in our blog .
What can be the elements of "disturbance" in the welding process?
The first certainly resides in the surface. Some materials are covered by rolling or drawing residues such as calamine, oils or protective chemical products, oxides and even incrustations.
An apparently clean metal may not be clean precisely because the layer of "polluting" element is sometimes not visible to the naked eye, such as alumina (aluminum oxide) or some protectives which form a transparent film.
It is therefore good practice to clean the surface using special abrasives, which vary according to the type of material.
In our abrasives section you can find numerous products that adapt to the type of work to be performed, and you can also see our demonstration videos.
This cleanliness is especially important in TIG welding since, being more concentrated, any inclusions of "foreign" materials cause visible defects.
Also in the case of electrode welding it is important to clean the weld bead well because if it is re-welded or over-welded, the electrode coating residues do not always come to the surface in the subsequent weld pool.
In the case of basic electrodes with double coating (E7016), for example, they allow the previous slag to rise to the surface in the next step, therefore thorough cleaning of the weld bead is not essential, although obviously recommended.
Wire welding is usually the least problematic for various reasons, one of which is the lack of coating (with the exception of flux-cored wires) and therefore there are no specific contributions of extraneous elements that need to be eliminated. Furthermore, the high amperages with which welding is normally performed tend to "burn", eliminating many of the protective elements of the material to be welded.
In summary, it is always advisable to proceed with a preventive cleaning of the material to be treated, always using a product suitable for the type of metal.
We invite you to consult the further articles on this blog and to watch our videos about it.