Metals such as iron, steel, bronze, aluminum, etc., are highly resistant and durable materials. For this reason, they are widely used in construction as elements in structures; or as finishes in cladding. However, they are very sensitive materials to environmental agents, as they are the source of oxidation. As a result, the parts deteriorate and can lose their usefulness completely and even cause illness.
Taking into account the production costs involved in making metal, as well as its durability, we must ask ourselves: When should we restore and when should we buy something new? We will then answer this question so that we can make the best decisions for our projects.
Metal restoration is a process that aims to preserve and protect metal objects. This includes tasks aimed at preventing or delaying metal damage. Because, despite being materials considered resistant, stable and durable, they tend to suffer deterioration generated by the passage of time or exposure to environmental agents. In this way, trained people with the necessary knowledge, tools and materials are given to the task of restoration.
To restore metals, it is necessary to consider the extent to be treated and the type of metal of the part, as well as the damage it presents. This is because metals are classified into ferrous and non-ferrous. In this way, the ferrous are those formed by the alloy between iron and carbon, while the non-ferrous are those that do not have iron in their constitution, such as copper, aluminum, nickel, etc..
Depending on the size of the part and the damage it has, it is possible to restore it on your own. However, it is important that these activities are carried out by expert personnel, because they handle elements that can be harmful to health, such as rust or chemicals.
Metal is a material with an almost permanent durability. However, when exposed to environmental abrasion for a long time outdoors, they can suffer considerable damage that can damage the part, such as oxidation or some breakage. That is why, by means of restoration, we seek to recover those pieces that still have a useful life.
The first thing we must do to begin restoration is to prepare the metals for further treatment. This way, we clean the parts removing any kind of dirt, such as dust or grease. Then we sand, to eliminate the remains of paint and rust, which can continue to deteriorate the piece, despite the treatments. Finally, we proceed to the restoration of the metals; in this sense, the processes that are carried out in the same one, are the following ones:
Initially, a primer or preparatory coating is applied before the part is painted. This ensures better adhesion of the paint to the surface, extends its durability and additionally protects the metal. Also, when we paint the piece, we can apply it by hand with a brush or spray; we will always recommend sprays, because despite being more expensive, the finish is more tidy, as it does not leave brush marks. Another option is the use of the paint gun, which works with compressed air. In this way, it works like an aerosol paint, in which a device distributes the layers.
If your metal part is rusted because of old metal, was of poor quality or is not even galvanized, it can be cleaned by sandblasting. It consists of smoothing, forming, and cleaning a surface by forcing solid particles at high speeds with compressed air.
The effect generated is similar to that obtained using sandpaper, but the resulting finish is much more uniform, so there are no problems with corners or cracks. With this technique, your metal pieces will be about ten years younger. The cost of the application will depend on the size and shape of the piece, which ranges from 50€ onwards.
It is ideal for metals that are exposed to strong environmental conditions such as moisture, or chemicals. This type of coating does not disappear, we can apply it to any metal and it resists cracks or splinters. It also offers a superior finish, as well as great durability, which extends the life of the metal.
The technique consists of applying a thin layer of plastic powder with the help of an electrostatic powder gun. This is maintained in the part by static electricity, like dust adhering to the TV screens. Once the metal has been covered, we melt the powder in a 200°C oven; there it will turn into a gel state. After curing, the gel will harden and become a fairly strong plastic coating.
The cost of this process also depends on the size and shape of the part. In this sense, factors such as the extension are taken into account, is it a smooth or molded, square or round metal? In this way, once these characteristics have been defined, the value of the work can be established.
Steel, when unprotected, is prone to oxidation, an electrochemical reaction between iron and the environment; extremely difficult to recover once damage occurs. Therefore, to protect and prolong the durability of the metal, we recommend that it be subjected to the galvanizing process.
Galvanizing is a method of coating that we use on corrosive metals, such as iron and steel, which we do with the help of other non-corrosive metals. In this way, we melt zinc and apply it to the metal to be treated through a hot dip. This will provide a thick layer of protection to the metal. On the other hand, the cost is estimated by the kilograms to work, starting from 1.5€ for small pieces, which will decrease when the quantities are larger.
Welding is carried out in the event of metal breakage. With this, we seek to preserve and conserve the pieces we already have, without having to change them. No matter the size, we can weld on chairs, tables, grilles or doors.
The most recurrent problem that occurs in steel parts is the corrosion produced by rust; it can happen externally and internally. Thus, when oxidation occurs on the outside, the problem is not so severe and can be easily restored. However, if the rust is inside, it is possible that when we notice it, the damage may already be severe. In this order of ideas, we have to:
In that sense, what is the best alternative, to restore or buy a new piece? Usually, the restoration is an excellent choice, because it is possible to preserve the same pieces, without major work. However, when we have parts with oxidation from the inside, usually when we notice it, it is too late. Therefore, the best solution for such cases is to buy and replace the part with a new one.
However, it is necessary to think about what works best for your pocket; if the damage is serious or the area to be treated is quite large, we need a cost analysis and evaluation. With this we intend to compare the price of a new piece in relation to the restoration of the one we already have.
Finally, oxide is not only harmful to metals, it is also harmful to human health. A wound caused by a cut or puncture with rusted metal can be fatal to people. They often become infected very quickly, and can trigger the popular and feared tetanus and even gangrene.
Wounds caused by oxidized metal require special and constant care, because they become infected quickly and easily. For this reason, the most advisable thing to do in these cases is to go to a medical centre. In this way, they will clean the wound properly and give us special antibiotics. To conclude, it is important to remember the importance of getting the tetanus vaccine, because it will fight the bacteria that causes the disease and is usually linked to the rust.