Yes, it can be done! A lot of us powdercoat our firewalls etc so I'm happy to say that you can repair and even buff some scratches in the powdercoat (granted it's gloss). You don't want to use regular polish but instead find the stuff their using for polishing plastic headlight covers, Helmet faceshields, etc. After all, powdercoat is simply plastic. I use the 3M Plastic polish. Then I follow it up with some basic Carnuba liquid wax. Be sure to test it on a small inconspicuous area first! I was able to take out some minor scratches on my firewall and some major ones as well.

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