As a bonded metallic, does Super Chrome Plus require a top coat for corrosion resistance or is my understanding of a bonded metallic wrong?

You are correct! As a bonded metallic, Super Chrome Plus does require some sort of top coat application to prevent premature oxidation. This is required in most situations, especially if exposed outdoors.

Does the super chrome need a base coating such as a primer or can you use a primer?

The Super Chrome Plus does NOT require a base coat as it’s considered a base coat in itself. However, you’re more than welcome to a apply a primer coat down below it for added protection!

When applying a clear coat like Clear Vision PPS-2974 over Super Chrome Plus UMS-10671 the end results always turns out looking like a darker grey. How do I prevent that from happening?

When applying Super Chrome Plus UMS-10671 it is extremely important to fully cure before applying a clear coat like Clear Vision PPS-2974. The thickest portion of your substrate MUST reach curing temperature of 375 degrees F. before setting your 15 minute curing timer. If measuring your substrate through a chrome powder with an I.R. thermometer the reflective property of the Chrome finish will give a false reading. This false reading could be 20-30 degrees off. If your I.R. Thermometer reads 375 F, the part metal is likely 20-30 degrees F. cooler. Leave the piece in longer to assure full cure. For example: A heavy aluminum wheel could be curing in an oven for 45 minutes or more. 30 minutes for the thickest portion to finally reach 375 degrees F. plus 15 minutes of cure time. Generally, modern powders have over-bake protection built in. This means that time in the oven can be extended significantly but not an oven's temperature. Keep the oven at or below the recommended cure temperature for your specific powder. Downloadable Technical Data Sheets are available on our website for each color.