Galvanizing. Pros and cons of different galvanizing methods. Practical recommendations.

What is galvanizing?

Galvanizing is one of the most reliable and time-tested ways to protect metal against corrosion and improve the appearance of the product. Most enterprises, including private electroplating, use this particular electroplating method coatings due to the availability of the materials used and the quality of the resulting coatings.

What are the types of zinc plating?

Cold galvanized metal. What is cold galvanizing? – when a zinc alloy solution is applied to degreased metal by dipping or using a sprayer (brush), roller. The main disadvantage of this method of application is uneven coverage.

Hot dip galvanized. What is the difference between cold galvanizing and hot galvanizing? – During hot galvanizing, the metal is immersed in a hot zinc alloy. With a good preliminary preparation of the metal surface, a good quality is achieved. However, this method of coating requires a very high level of organization of production, huge volumes and expensive equipment. And a very significant minus is the high temperature of the working bath, up to +500 degrees C. The main task of these types is to protect the metal from corrosion.

Thermal diffusion galvanizing of metal – metal treatment with zinc in a vapor state. This type of galvanizing is quite expensive, but it has very high decorative and quality characteristics.
The advantages of this type of zinc coating are high productivity, low cost, coating uniformity while maintaining the size and shape of the product. As well as coating products of complex shape.

Galvanizing of metal – applying zinc to metal for account of the electrochemical effect. This method is suitable for all types of metal. The product receives a uniform shiny coating with a zinc layer thickness of 5 to 40 microns.

Galvanizing is widely recognized as the most effective. Therefore, let us dwell on it in more detail.

The galvanizing process takes place in baths filled with a special electrolyte composition. The quality of the resulting coating largely depends on the composition of the electrolyte.

There are two types of zinc plating:

1. Slightly acid galvanizing
2. Alkaline .

The most commonly used plating method in weakly acidic, simple galvanizing electrolytes. They feature a faster coating rate. At the same time, a high level of concealment and a good appearance are maintained. With this type of electroplating, bright additives and passivation are used to improve the appearance.

A bit of history. In the early 70s, Likonda multi-component gloss additives with components A, B, C and rainbow passivation Likonda 2A-T were used. A little later, they were replaced by gloss additives DHTI-102 and DHTI-104 with additional components that improve the quality and decorative properties of the coating.
Now they have been replaced by more modern and versatile BSK glosses.

Why use BSK glitter additives?

Combined use of BSK-A shiner paired with BSK-B enhancer is especially effective. The combined addition of these additives to solutions even with a low current density makes it possible to obtain fine-grained, more plastic and high-quality coatings.

Detailed description and application guidelines:< /span> BSK-A BSK- B

The final phase of galvanizing can be considered the passivation of the already obtained coating.

What is passivation for? Passivation enhances the strength of the zinc layer, increases the wear resistance of the coating, including at high humidity, exposure to acid fogs and salts. An important quality of passivation is to improve the appearance of the product. Although the main and most important advantage of this type of treatment is the protection of the zinc layer from corrosion.

To improve the decorative qualities of the coating, we recommend using iridescent or blue passivation.

          Detailed description and usage guidelines :   Rainbow Passivation Blue passivation

Novohim specialists will always help you choose the best type of brighteners and passivating additives. Application guidelines and samples are available upon request.