You can't assume he has OCD because he does all these projects. He might be obsessive and compulsive about perfectionism, but that doesn't mean it's a disorder. It's only a disorder if it disrupts his life, and he doesn't enjoy it. Some people are "neat freaks" and like things to be as perfect as possible. They may have obsessive compulsive personalities; again, it's not a disorder (OCPD) unless it's a problem.

But if it's a problem for you, you need to talk to him about this. There's no harm in him going in for an evaluation, and you can suggest that. But he might just really like doing these kinds of projects.