Uncoated aluminum railings on hangers on the conveyor
Last month we told you about powder coating standards and what they mean, but just as important is the process by which the aluminum is coated. Having AAMA 2604 or 2605 standard coating is good, but that high standard doesn’t matter if the coating isn’t applied correctly.
The powder coating process is important because it forms the basis of weather protection and longevity for your aluminum railing, fencing, or other outdoor products. An incomplete process or one full of shortcuts will result in a less-than-adequate finish that won’t hold up to the weather over the long haul.
A good powder-coating process has multiple stages that prepare, coat, and finally cure the aluminum. Here are the phases that Key-Link’s aluminum goes through.
Hanging
Raw parts are loaded onto hangers designed specifically for their shape. Hanging this way allows the entire surface area to receive coating as they move through the process on a conveyor
Cleaning
This stage is important because dirt or any foreign substances on the raw aluminum could prevent the coating from sticking properly. Even normal oils from a hand could prevent adherence of the coating! Key-Link aluminum goes through a 5-stage pretreatment process to thoroughly remove dirt and all other residue to prep it for powder coating.
Drying
Wet aluminum cannot hold a coating, so the newly cleaned parts go into the oven for a baking to remove all the water and dry the raw material completely. Parts spend 2-4 minutes in the oven during this phase of the process.
Coating
This is where the actual coating is applied to the aluminum. The conveyor moves at a steady pace while the powder coating guns move in concerted motion up and down to evenly spray the aluminum and ensure a uniform coat. The angle and degree of the applicator tips changes depending on the size and shape of the profile we’re coating. If the items are a small batch, they go into our booths where they’re coated by hand. This keeps the main conveyor free for larger orders.
Powder coating guns spraying coating
Curing
Once the piece has been completely coated, it goes back into the oven for 8-10 minutes for the curing. Here’s where the coating is “baked” on for colorfastness and ongoing weather protection.
Checking
Once it’s unloaded from the hangers, quality technicians check the newly powder-coated item against a set of standards to make sure the piece has a uniform color and finish. Technicians are also checking the powder coating throughout the day to make sure it’s adhering properly and meets the stated AAMA standards.
Once the piece has traveled through the powder coating phases, it’s ready to be carefully packaged and then shipped. The complete powder coating process takes about 90 minutes, and when it’s complete, the railing or fencing is ready to be placed outdoors and maintain its good look for years.
Beautiful finished and powder coated railing