“We received a large shipment of storage racks which were powder coated with green and yellow paint. They were stored outside for 4 weeks during times of heavy rain. The racks are now showing rust at the weld points and certain areas where the steel part meets another steel part. The manufacturer of the racks says that the rust is normal for the material being stored outside. Also the material has a great deal of shipping and scratching during the shipping / unloading process. My understanding of powder coated products was that it would prevent the very things I mentioned. Is there some sort of specification for powder coating that varies based on the application and what is reasonble for me to expect of the material that is powder coated? How do I know that the manufacturer did not have some sort of QC problem with their powder coat paint process? Are there consultants that can help? “
“It sounds as though there could be some process problems at your supplier’s manufacturing facility. Powder coated steel products are used in extreme outdoor environments without corrosion problems. For this to occur you need to first select corrosion resistant steels. Next you must clean and pretreat them properly before coating. And finally, you must select and apply a powder coating that has the inherent properties to meet the fielded conditions.
It sounds as though your shelving supplier did not meet at least one of these criteria. Along with writing the answers to the Powder Coating Net’s Tech Talk section, we are consultants to the powder coating industry. We are an objective technical resource to many clients who are using or specifying powder coatings. To get more information on our company and services, please go to our web site.”