Join Date: Jul 2018
Location: Dutchess County, NY
Powder coaters have to clean off the racks that they use for electrical contact on the production line as the powder builds up and creates an electrical insulator. To do this, they "burn it off".
The polyester powder is attached to the production parts with static electricity with the parts given a negative charge and the powder given a positive charge. The static makes the powder cling to the part. At that point it goes through an oven to fuse the powder to the part. The powder fuses at 300 degrees and is allowed to cure at 400 degrees for ten minutes. The exact temperature varies by the formulation of the powder.
The "burn-off" temperature is 575 to 800 degrees Fahrenheit. Most heat guns will reach 1,100 degrees Fahrenheit, so if the part will handle the temperature, then a heat gun is the way to go.
Originally all powder coating was epoxy and it was a very, very hard finish. But it was not UV resistant and it faded badly. Today almost all powder coating is polyester, which is UV resistant but fairly soft and scratches easily.
Occasionally we get a job that calls for epoxy, but almost always because of its chemical resistance.