I just purchased new front fenders door skins and rockers. First question what do you guys paint the insides of these pannels with? Second for the rockers and door skins weld them or use the proper 3m pannel bond glue?
When I did the door skins on my '70 Formula I put sound deadener on the inside of the skin. I covered the entire panel with it leaving about an inch all the way around it. Then I ground that black EDP coating off the the edges then ground off the mating edge on the door shell. Then I did a test fit of the two parts to be sure everything is going to line up. Once I had the skin and door shell positioned where I wanted it, I made reference marks on both parts then removed the door shell off the skin. Then I used that 3M08115 panel bond. I put a very small bead on the door shell lip then lade the door shell onto the skin. I put the skin on my parts stand where the curve lays into the stand to avoid any damage to the skin. Also, a big piece of cardboard from the box that the skin come in was lade onto the parts stand. The cardboard assists in keeping the skin and door centered on the parts stand. Then with a helper I lade the door shell onto the skin. Once the reference marks were aligned I used my body hammer and the biggest dolly I had to hammer over the lip. It's time consuming and don't go crazy hammering on the lip to seat it to the door shell. If to much hammering force is used the skin will have a bent up edge around the door shell. Doing a door skin seems easy and in terms it is. But, those little things that aren't done can and usually will make the job a lot harder than it has to be. Then the top edge of the skin where it meets the door frame it has to be spot welded in place. I spot welded mine about every 3 inches. When welding these areas, be sure to do it in small/short welds so the heat of the weld doesnt effect the door skin and warp it.
As for Painting these parts. I always sand the areas with a 220 grit paper, get it all smooth, sand out any chips or scratches. Then apply a coat of epoxy primer to the entire area. Let that sit for at least 30 minutes, maybe longer depending on the climate temp. Then I paint the parts with the paint/color that the car will be.
In a nut shell, this is how I would handle doing the job(s) you described. Hope this long message is of assistance for you. Best of luck.