I just finished painting my door jambs, under hood, under trunk lid using the back tape method outlined in the Paintucation DVD. I’m using Eastwood single stage urethane with no clear for the jambs. I’m getting ready to back tape the jambs, etc. now exposing about 1/8″ of the urethane so I can paint the rest of the car. Since it will be outside of the 18 hour recoat window, how should I abraded the single stage? The single stage urethane spec sheet recommends 400 before recoat. Can I use gray scotch brite or maroon scotch brite or 600 wet sand? The car has already been wet sanded and ready to paint using 600. I’d like to use the gray scotch brite to prep the entire car including the exposed 1/8″ of jambs but am worried the gray might not be enough to promote good adhesion.