I wouldn't suggest bondo. We used to race a C22 and did all the fun things you are engaged in now. There are some tricks. First off the recommended wait time is about one hour from sand blast to
paint!

We found fairing is best done with
epoxy and microballoon filler to the shape that you want. We used compukeel templates and 407. Perfect time to rebush and replace the pin and turning ball since you are at it. After fairing to your desire , remember cast iron doesn't sand or grind very well, we out 5 coats of
epoxy w barrier coat additive over everything. Bottom
paint of your choice. If you trailer your boat the job will outlast you , The Catalina 22 National Association has tons of info on this operation btw. Just don't call Frank Butler as he gets amped up when he thinks you expect your C22 to be a Ferrari instead of a Volkswagon. That said we loved that little boat and wiped the eye of an awful lot of Rolex wearing folks.
