Typically you want to use a clear coat that is sold for Spot/Panel type work. That type dries within a few minutes of being applied.

Duane uses a Urethane spot panel clear coat with a fast hardener. I believe his is Nason brand that is available through O'Reily Auto Parts stores.

I have Acme Finish 1 Ultimate Spot/Panel Clearcoat. I've been using the fast hardener.