Is It Necessary to Sandblast Prior to Powder Coating?

Sandblasting is a great way to prepare any part or surface for powder coating in Washington. Is sandblasting always necessary? No, but you can generally expect much better results from the powder coating process if you prepare the surface with media blasting first.

Before powder coating, the item to be coated must be completely cleaned of dirt, paint, rust, oils, damaged plating and corrosion, all of which can result in the powder coating failing to properly adhere or to otherwise have some imperfections in its finish.

Sandblasting both provides you with a deep cleaning of the part or surface you are preparing to coat, and also gives the part a surface profile or “tooth.” Think of the little scratches that are left behind when you use sandpaper on a piece of metal—those little scratches make it easier for paint or powder to stick to it. This is why sandblasting is so beneficial—scoring the surface provides a much better means for the powder coat to grip on to it. Otherwise, if the surface is perfectly smooth, the powder coating could peel right off in what is referred to as delamination.

Sandblaster usage

The sandblaster tool itself uses high-pressure air to shoot sand or other media at the surface. When the media hits the surface, it knocks off paint, dirt, scale, rust and any other types of coatings or contaminants to create a clean, bare surface. You can place the sandblasting gun inside a sealed cabinet called a “blast cabinet” to hold all of the media and allow for easy reuse, or you can find sandblasting guns and nozzles that can be used outside of cabinets. The latter is most likely to be done if you have a special blast room, or if you’re sandblasting outdoors. Make sure you always wear the proper personal protective equipment to keep your eyes, skin and lungs safe.

The sandblaster will require the use of an air compressor to deliver that high-pressure air. You’ll need a pretty good-sized compressor for this, as the sandblaster will consume a lot of air in a relatively short time. If you’re doing your own sandblasting, you should do some research about the kind of air compressor to get if you do not have one already. Keep in mind that air compressors, even used ones, are not cheap—you may want to try getting by with a smaller compressor if you can. The air must be dry, as well—otherwise, the media will mix with the moisture, and that will cause clogging in your gun.

Generally speaking, it’s smartest for you to work with a sandblasting professional to get the job done. They’ll be able to do it safely and efficiently and at a much higher quality than you’re likely to achieve as a beginner, and you won’t have to spend all the money on tools you may not use more than a couple of times.

For more information about sandblasting before powder coating in Washington, contact Powder Vision Inc. today.