Unfortunately, there's no clearcoat on the market that you can buy over the counter that won't dull the finish of aluminum powdered paints to some degree. Testors offers the clearcoat, as it has the same base as what they add their aluminum powders to. Alclad has a clearcoat that is specially formulated for it, so that it'll retain the appearance of chrome. You might want to ask them through an email, if you don't see anything on their site that might help you. www.alsacorp.com