September 23, 2019
powder coating

Tips for quality powder coating procedures

Powder coating is one of the latest surface furnishing methods that are available today. It involves the application of dry paint on a part of metal or other material. The finished product is similar to applying 2-pack wet paint. Unlike wet painting where the solids are suspended in the liquid, the solid paint does not need any liquid to have it done.

Application of powder coating

There are two commonly used methods in the application of dry paint. The first method involves the lowering of the item to be painted on a fluidized bed of powder that may or may not be charged electro statically. The second approach includes the application of the electro statically charged paint by the use of a sprayer. After any of the two methods is used, the part that has been sprayed is then placed in the oven where the powder particles are melted and turned into a continuous film.

Finishing

There are two types of surface finishers. The most common finisher involves the use of thermoplastic powders that usually melt when they are heated. The other type involves the use of thermosetting powders that do not re melt on reheating. When the item is being cured, the chemical reaction causes cross-linking between the particles of the powder giving the coating some properties that are desirable.

Preparing the parts for coating

Preparation is essential for good results when it comes to powder coating. Lack of proper preparation is to blame for a vast majority of failures in the coating process. The preparation of every material differs from others. However, the preparation of several metals is similar. It involves the cleaning, rinsing, etching and washing in phosphates or chromates and finally doing the de mineralized rinse. Ask the Winnipeg powder coating technician you hire about the above preparation procedures.

If the material contains grease or oil, use some with alkali or a neutral detergence to clean. Surface etching helps deal with oxides that may have formed. Phosphates and chromate solutions form a conversion coating on the surface of the metal. The coating becomes chemically attached to the surface and helps to stick the powder film to the surface. The de mineralized water removes any excess solution and salts before the coating process. A metal such as zinc uses iron phosphate and acidulated rinse for the same purpose.

The application process

Electrostatic spray

The electrostatic gun applies the powder on a part, but the powder must be fluidized so that the powder becomes easy to flow through the noose of the gun. Fluidizing the powder also helps separate individual grains of the powder so that their electrostatic charge is improved.

Sometimes you may need to apply some coarse surface application on the surface with a process called sandblasting. The Thompson sandblasting contractors use a similar process to give the material or surface a coarse finish for special application.

There are many types of paints and colours available for application in powder coating and sandblasting. Thompson sandblasting experts can guide you on the thickness and application procedures. Likewise, Winnipeg powder coating contractors can be of assistance in various powder coating applications including preparation and curing process.

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