If you are starting out in the powder coating business, then this article couldn't have come at a better time. The write-up will explore some of the common challenges you are likely to encounter during the powder coating process and how to fix them.
Pinholes -- A powder coated product should have a smooth, glass-like finish. However, if you see tiny dimples on the surface of the product, then you have a problem. Two issues can cause pinholes on a powder-coated surface. Firstly, failure to clean a metal product properly after sandblasting might lead to entrapment of contaminants under the powder finish. Secondly, contaminants might embed on the surface of the powder coat before baking and lead to a pinhole appearance. To prevent pinholes from forming on your powder coat, make sure that you wipe off the product's surface thoroughly. In fact, instead of hand-wiping the surface, consider using a dip tank that eliminates the probability of dragging dirt across the surface of a product. Another solution is to ensure that the powder coating booth has filter doors that will prevent outside dirt from mixing with the finish.
Insufficient Powder Wrap -- A poorly done powder wrap can make a finished product look terrible. Typically, a low power wrap leaves a metal surface with a grainy appearance instead of the glass-like finish you are looking to achieve. A common cause of insufficient wrapping is poor grounding. For powder coating to adhere to the substrate adequately, the uninterrupted charge must pass through the grounding. Therefore, ensure that you have a proper earthen grounding and that the point of contact with the metallic product is free of contaminants such as dirt, rust or paint.
Poor Thickness -- The thickness of powder coating determines the overall appearance of a product. A thick coat will achieve a sagging effect. On the other hand, a thin layer will make a product appear grainy. A myriad of factors cause poor coat thickness; however, poor gun settings and worn out powder coating equipment are the primary culprits. If the powder coating gun is not set to the required kV settings, it is more than likely that the coating thickness will be affected. Therefore, always ensure that you have the correct settings before you start the powder coating process. Additionally, an old powder coating gun might spit too much powder or withhold some of it. Therefore, it is essential to maintain the powder coating equipment and replace any worn out parts accordingly.