Powder Coating Durability

Dear Joe,

I am currently incarcerated in an Ohio prison and have a question regarding powder coating durability. I have always heard that powder coatings are one of the toughest industrial coatings and that they last forever. Some of my neighbors on the row and I have noticed that the finish on the cabinets in our cells scratches off easily. Our correction officers tell us that the cabinets are refurbished and powder coated. So what’s going on? Is the excellent durability of powder coatings really a myth?

Sincerely,

Keith

Hello Keith,

Thank you for your questions and let me try to answer them. First of all, I can verify that indeed the metal cabinetry in your prison is rehabbed, and that part of that process involves powder coating. I used to visit one of the prisons and they have a shop there. While I was there I inspected some of the cabinets that had been refurbished. They looked awful. The beige powder coating they were using appears to be a very low quality, semi-gloss hybrid (epoxy-polyester). From its appearance it looked to be a highly filled semi-gloss product.

The poor performance of the finish can be probably attributed to a poor-quality product deliberately made of low-quality ingredients including a high concentration of cheap filler. I was not able to inspect the powder coating line, however I suspect that the metal cleaning and pretreatment may be inadequate for good adhesion of the powder to the substrate. In addition, I wonder if the powder coated parts are being adequately cured in the oven. If the powder does not reach the recommended temperature for the prescribed time then the coating performance will inevitably be poor.

The coating failures you and your friends on the block observe are probably due to a convergence of a number of negative factors – low-quality powder coating (yes, a poor quality powder can be concocted), applied to an unclean surface and improperly cured in a poorly controlled oven. Perhaps the powder shop can be contacted and offered advice on how improve their powder coating process.

Best regards,

Joe Powder

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