I’ve spent some time recently experimenting with different colors by coating YETI cups. I love doing them because the coatings come out so smooth and glossy and full of shine. YETI’s are easy though, because they come in brushed stainless steel. It’s much harder to get that glossy finished result when your item already has a paint or coating that must first be removed.
What if the metal has to have old coating removed? Can you still get that same glossy smooth finish?
Last week a customer brought us two bike frames that they wanted powder coated. These were quality frames, new from the factory, and had a primer and paint already applied. We knew that to get the that spectacular smooth finish we’d need to use a really fine media ( we chose a fine glass bead) and blast them at a lower pressure. Basically we etched away the paint, little by little, while still leaving the metal with a smooth fine finish.
Next, the frames were dipped in a chemical cleaner that will remove any other contaminants and residue of previous processes. Then, the frames were hung and prebaked in the oven for slightly longer, and at slightly higher temperatures than the final powdered bake. This causes ‘outgassing,’ or the expelling of any gases remaining in the pores of the metal. This step is necessary to avoid any bubbling, blistering, or peeling in the final powdered finish.
Finally, the frames were moved to and hung in the spray where powder was sprayed using an electrostatic gun. The powder receives a positive electric charge, and is then sprayed towards the frames, which were grounded. Through the application of heat and energy, the metal part attracts the powder like a magnet.
Finally, after the proper amount of powder had been applied, the frames were baked at about 375-400 degrees for 15-20 minutes. During this time, the powder adhered to the frames until it melted and fused into a uniform, hard coating. The result is a shiny, smooth quality surface that will hold up better and last longer than traditional paint.
On my next post I’ll show you some of those AWESOME YETI cups!