How Powder Coating is done

Powder coating is a process of coating metal with a plastic finish applied in powder form and baked to a fluid state to bond it to the metal surface. Powder coating has many advantages over traditional liquid coating: It’s better for the environment, applies thicker without running, and is easy to style with. Although certain aspects of powder coating can be tricky, it’s certainly not difficult, especially for an enterprising soul. Proper cleaning and tools can be the difference between an amateur and a good powder coating job.

Determine the type of material you are going to powdercoat and then select a suitable powder for the finish. Powdercoating is done with thermoplastic or thermoset polymer powder, and these materials are formulated for bonding with different base metals to give the best results.
Clean the base metal thoroughly. Using bead or abrasive blasting on hard metal, such as cast iron or steel, will remove mill and rust scale, dirt and foreign materials. Chemical solvent cleaning will remove any grease, oil, or paint, and light sanding can be done to finish preparing the surface. Aluminum, magnesium, and other soft alloy metals can be solvent cleaned and wire brushed, or sanded if needed.

  • For example, you might sand-blast whatever you want to powder coat until it’s down to bare metal. This is the first step in the process. If you don’t have access to a sandblaster, you can also use a wire wheel, bench-grinder, or even sandpaper. Just as long as you get the material down to bare metal.
  • The next step is to strip the metal of any remaining grime or gunk. You can achieve this by soaking the item in acetone (if the item is small enough) or by wiping it with an acetone-soaked rag.

Apply the powder to the object to be powder coated. This is done using a “gun” or compressed air sprayer which electrostatically charges the powder material so that it sticks to the grounded base metal object receiving the coating. These guns are available from various suppliers, and cost as little as $100. For experimental purposes, you can apply the powder to a flat metal surface by dusting it directly on, and spreading it to a thin, even layer.

  • Make sure you have your electrostatic charge hooked up to whatever part you are coating. The powder you use won’t properly adhere unless it’s given a charge to hold onto.
  • After applying the coat but before curing, be careful not to brush or blow on the powder coat, as this will cause some of the powder to fall off, leaving you with a less precise coat.

Cure the metal at a temperature appropriate for the powder material you use. A conventional oven is suitable for this purpose if the metal is small enough to fit, otherwise, an infrared heat lamp or other flame less heat source needs to be used. Normally, the object is heated to 350° to 375° F (175° to 190° C) for about 10 to 15 minutes, and allowed to cool.

  • You can use a conventional oven to powder coat smaller items. Just be sure that you won’t be using the oven to cook food after the powder coating. Once you’ve used an oven to powder coat, it absolutely should not be used for cooking.