I'm running 355 wheels on my 328. All are fronts, and all were bought used. I've had them on the car about a decade now. The other day I glanced inside one of my rear wheels and it looks like the paint is peeling off. These pics are the worst wheel, but I have another that is starting. No brake fluid leak, which was my first thought. The stuff coming off is matte on the outside and shiny on the side toward the wheel. Ideas? Bad refinishing? Is it dangerous to continue to use them? Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Appears to be an improper base coat (or likely no base coat) under the finish. Check the threads here regarding Braden's refinishing 355 wheels. They explain how to do it right. The 355 wheels are magnesium and need a special base coat (I believe its made by 3M but can't remembers its name) otherwise the paint will blister or delaminate over time.
Image Unavailable, Please Login Yes, Dow 7 is a chemical conversion process similar to alodine on aluminum. It's a dipping process, it's not a coating. After Dow 7, within a limited amount of time, primer should be applied. Dow 7 is critical for adhesion and protecting the metal. Here is a photo of wheels I had Dow 7 process done on.
Maybe Ferrari is making the wheel inserts out of the wrong matrerial "Dow 7 is a good choice for both new and overhauled parts that have dissimilar materials such as inserts, or where conditions will tolerate a less robust and less costly alternative to Dow 17 anodizing. It makes an excellent paint base and provides the best corrosion protection of the available chemical coatings for magnesium. "
