The authoritative public forum
  for Metal Finishing since 1989
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Soft Paint Issue

I need to finish a sheet metal box I made for audio amplifier. I tried spray painting it with car paint but it scratches very easily. Would baking help? How would I apply a baked enamel finish? What kind of paint, what temperature,how long?

Joe Rogers
hobbyist - Calgary, Alberta, Canada
2003

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2003

Baking will work if you have a paint that contains a cross linker that activates at a minimum temperature. They are generally not available to the public. Bake times and temperature vary, the shorter the time the higher the temperature. 30 seconds at 650 °F is not unusual for a lab bake for a coil line. 15 minutes or more at 450°F is typical for slower conveyor based systems. These times and temperatures vary depending on type of coating but they are ball park.

Due to the solvent release during baking it is not recommended baking be done at home with a range or similar equipment. You'll blow the door off. An convection oven is required with the heating element isolated from the baking area.

A polyester coating would be a good choice.

Ronald Zeeman
Coil Coating - Brampton, Ontario, Canada

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Take it to a car repair facility or make friends with a guy who works as an auto painter (winter may be slower turn-around due to the # of crashes). They can shoot it/bake it in a few hours.

Douglas Corbett
- Salt Lake City, Utah, USA
2003

Dear sir, you may try a phenolic resin used for woods which will give good scratch resistance. You can also consider an epoxy.

Dinesh
- Chennai, Tamilnadu, India
2004