Weld bleaching methods

Weld bleaching methods

Date 06/05/2019

In the mechanical engineering industry, welding is one of the methods considered to be effective in linking and repairing metal parts. There is the disadvantage  is that after welding, it leaves black marks on the surface of the weld. Therefore, additional cleaning steps are required to ensure the aesthetics of the product after welding.


Cleaning a weld is the process of using external action measures to remove the black spots on the surface as well as return the best possible color of the metal.


Weld removing methods


Weld removing usually has the methods of physical impact, chemical impact, electrochemical methods, ... Each method has its own advantages and disadvantages, they are applied to different welding techniques. .


1. Weld by physical impact method:

This is a method of purging using special grinding and polishing waxes to work on the weld. The advantage of this method is relatively easy to apply. This method is also known as metal polishing. However, this method is only effective for welds located on flat surfaces or easily eroded corners. In the case of welds in the corner, inaccessible grinding machines, this method is almost impossible to apply. The quality and aesthetics of the weld after applying this method depends on the skill of the welder. If we overhand our hands, we have to take further processing of scratches, convex concave caused by grinding machine.



2. Weld removing by electrochemical method:

Welding after finishing is treated by electric current combined with specialized chemicals that conduct electricity. In essence, this is the method of dealing with electrical currents involving corrosive chemicals to restore the appearance of the metal. Compared with physical method, this method gives higher efficiency, faster processing time and can work in difficult position such as corner, hidden edge. However, this method requires a higher investment in machinery and more difficult to use than other methods.


3. Weld removing by chemical detergent method:


This method uses chemical coating on the weld and by the corrosive action of the chemical to clean the metal. As the process of corrosion ends, the black spots on the metal surface are generated by the heat being cleaned. Chemicals are mixed and mixed in different proportions, applied to different metals according to the manufacturer's instructions.

The advantage of chemical waxing is that it can be used at any welding location, with high cleaning ability and without the rigorous demands of the welders. The downside is that the weld need time to erode, so it will take longer than other methods.

Compared to physical impact methods, the weld bleach has more advantages. The weld detergent not only cleans the weld but also ensures aesthetics. Therefore, the weld detergent is often used in stainless steel welding.