Published

Settings for Metallic Powder

Are there any specific gun settings or other issues for powder coating with silver metallic?

Share

Q. Are there any specific gun settings or other issues for powder coating with silver metallic? Q.C.

 
 
A. Metallic powder coatings are typically denser than other powder materials. This can make it harder to fluidize and deliver the metal flake materials. In order to make it easier to fluidize, you should be sure that the air supply is properly dry. 
 
PCI recommends that the air be a +38°F (+3.3°C) dew point or lower. Also, use a feed hopper, not a box feed system. A box system may work, but it is more challenging to control the distribution of the powder by particle size and pigmentation. In some cases, it can be helpful to have additional inlets into the plenum to add more air volume. Additional pressure alone may not provide good fluidization, where additional air volume (CFM) without additional pressure (PSI) can be helpful. 
 
The spray gun should have a current limiter so that you can control the current draw. High current draw or rapid changes in current draw may cause differences in appearance as the gun-to-target distance varies. Limit the current to an optimum level, probably below 25 micro-amps. The electrode may get slightly heated and collect powder. It should be cooled and/or cleaned periodically. Use a reasonable flow rate and keep the gun back as far as practical. And make sure that you always have a very good earth ground.
 

RELATED CONTENT

  • Masking for Surface Finishing

    Masking is employed in most any metal finishing operation where only a specifically defined area of the surface of a part must be exposed to a process. Conversely, masking may be employed on a surface where treatment is either not required or must be avoided. This article covers the many aspects of masking for metal finishing, including applications, methods and the various types of masking employed.

  • Curing Oven Basics

    Simply heating up the substrate does not cure the coating. There are many variables to consider when choosing the best cure oven for your application...

  • Powder Coat MDF for an Enviable Finished Product

    Cabinet maker says powder coating on wood offers more benefits.