Many professional powder-coating companies will share the same process below.
The first step and one of the most important steps in powder coating is the preparation of the part, this will eliminate flaking or peeling. Unique Finish will clean off any pre-existing finishes or remove existing powder coating on the material by chemically stripping or media blasting using aluminum oxide. This will also remove oxidation and provide the necessary surfacing etching allowing the powder to create a strong adhesion bond.
Please make note that materials that are cast or that may be heavily oxidized will having pitting and require a filler to provide a smooth finish. Vein, Hammertone, crinkles or wrinkle will help hide some of the surface imperfections. Any parts that are oily and or greasy will incur additional charges for cleaning.
2. Pre-Baking/ Out gassing
The next step of the professional powder coating process is to pre-bake or outgas the part. This will help burn of any surface or material contaminants within the porous metal and will help avoid imperfections such as bubbles, fish eyes or dark spots.
Many porous aluminum and magnesium castings will experience out gassing even after pre-baking. Unique Finish will recommend staying away from highly reflective finishes that will make these imperfections more visible.
3. Surface smoothing/ Polishing
If your part requires additional grinding or sanding to even out or smooth surfaces, this can be done upon request.
Masking is done
anywhere needed and depending on the job will cost additional, however on most
parts it is included. This is required for mating pieces such as on flange
surfaces and or threaded parts or parts that require a press fit.
5. Powder Application
The selected powder coating finish is then transferred to the fluidizing hoppers to be sprayed by one of our professional powder coating guns. The powder is then applied in the spray booth to the part using electro static generated by the guns, this is regulated by varying the voltage and amperage. This will insure an even coat and that the powder adheres to the part.
6. Oven Curing
Once successfully coated, the small parts are placed in the oven, for large pieces or sets of wheels the spray racks are rolled into our large convection. Each powder has its own curing temperature and time. Depending on the metal density the curing time will vary.
7. Two Stage Powder
Candies, and anodized powder require multiple coats; the base coat will be a silver or chrome that will provide a reflective luster to the part. The metallic powder will require a top clear coat to seal and provide the additional color depth to the part. These additional coats can only be applied once the part has cooled to ambient temperature to insure uniform secondary coat. This increases the handling and preparation time and increases costs,
8. Curing/ Inspection
Once cured, the parts are removed and then allowed to cool. The masking is then removed and the final inspection is performed.
9. Customer Satisfaction/ Guarantee
Unique Finish will guarantee powder coated parts to be free of defects such as peeling or cracking for 12 months.