Cured RAPTOR can easily be touched up. Just clean the surface, sand and featheredge a few inches into the surrounding area, re-clean, and mix and apply as usual. No need to prime again unless you sand down to bare metal. Remember, if it’s been more than 5 hours since the last coat of RAPTOR has been applied, allow RAPTOR to cure for 24 hours, then lightly scuff and apply additional coat(s).