It is very difficult to repaint an object with a powder coating. After all, it…
Ferrous metals are iron and its alloys. These are the main metals on the market. They are dense, have a high melting point and high hardness. Examples of ferrous metals are steel, cast iron, ferroalloys, manganese, chromium and vanadium.
However, because of their peculiarities, painters may have problems with their coloring.
Rust appears very fast on ferrous metals. Sometimes various additives are added to ferrous alloys which make them more resistant to corrosion. But the problem still remains. Therefore, unlike colored ones, they must be painted. And any paint for this will not be suitable, otherwise the rust will quickly appear on the coating.
Choosing paints for ferrous metals, you should pay attention to their anti-corrosion properties. The best rust protection of all types of paints has powder. It is resistant to mechanical and chemical damage, it is not afraid of moisture and ultraviolet. And of course, the rust does not appear on it.
In powder coating the most important is the preparation of the part.
Preparation of ferrous metals for painting
Preparation of metal products is necessary to obtain a good adhesion of paint to the surface. And if this stage is bad, then all painting will be in vain.
It is necessary to remove rust, old paint, grease and other dirt with details by any means available in the production. You can do it with a burner. Thus, as a rule, massive structures are cleaned.
Rust can also be mechanically removed with sandblast or sandpaper, or chemically. Typically, the metal is immersed in a solution based on phosphoric acid. And they stand there for about three hours. After cleaning, the metal should be degreased and dried.
Sometimes galvanization is used to further protect the metal against rust. That is, the ferrous metal is coated with other metal by electrolysis.
After quality preparation, you can proceed directly to painting.
Ferrous metals: painting
Adherence to powder covering technology is very important so that the paint retains its properties and protects the ferrous metal from corrosion.
On the prepared metal put a powder by a special sprayer. They are electrostatic and tribostatic. The fundamental difference between them is in the method of charging particles. The first does this through an external power source. And others charge the powder with friction.
The product itself is suspended in a spray chamber during painting. It allows you to isolate the staining site and collect non-residual powder for reuse.
After application of the powder, the product is sent to the polymerization furnace. There, at high temperatures, the paint particles melt and form a perfectly even coating.
Powder painting can be applied manually or with the help of an automated paint application line. What is better depends on the financial capacity and production needs.