So you use primer, make repairs, sand the rocket smooth? Do you guys then paint, or do you primer again and paint over that, or do you hit it once again and then paint without sanding to give the paint a stickier surface before painting? Thanks for your responses. I'm always looking to improve.
Turely it totally depends on the model your working on. Primers are really nothing more then conversion coatings between the substrate(s) of our models and the dry paint film. They are mostly to be removed in an effort to prepare/repair the subsurface for the coming thin film of paint.
If after sanding down most of the primer we haven't without going into wood, paper or substrate, if we are satisfied with the surface being as blemish free as we will accept, it can be tac-rag wiped and go on directly to color coat(s).
If in some areas we've reopened grain or sanded to whatever is under the primer than another coat or two of primer are indicated. If the area is small, not in a noticable area or we're just tired of messing around, it's perfectly fine to apply a base color coat (I often use flat white for this as it sets up very quickly) then check the finish and these open areas for flaws. This Flat white base coat can be fine sanded to smooth any objectionable area or be completely sanded off and hit with another coat or two of primer if needed.
I mentioned "Finishing primer" in another thread. These are "Generally" White or Red oxide primers. I've stoppped using red oxide as it's just toooooo!!!!!! fine and make a god awful mess in sanding. White Automotive primers (NOT KILZS) have the next finest solids, laying down a thinner primer coat that generally takes care of those "sand through" areas with one or two light coats. Sand again with dry 360grit, tac-rag and on to our first color coat.
May I suggest a brief visit to narhams.org wegsite library section to download Tech-tips-002-005 may be of interest and will take the reader for raw base materials to babies butt smooth finished product. Even covers hand painting and lettering
Hope that helps.