I am posting this as a reminder of the steps I took to prepare the RV for painting the endcap with primer. If I am successful at doing a good job I wanted to document my process so I can repeat it. The steps are the same for painting a bin door as they are for the endcap. This may also help others who might wish to tackle such a project.
PREP STEPS
1. Wash area to be painted
a. wash using dawn
b. Clean any repair area with glass cleaner (sprayway)
c. then use 70% isopropyl alcohol or wax and grease remover to remove contaminants that can interfere with paint adhesion
d. always use lint free shop towels for wiping
2. Repair any bad spots
a. strip the current finish for any repair areas down to the bare metal/fiberglass
b. fill imperfections with body filler - Allow filler to harden per directions
c. DA sand 80 grit to flatten filler
d. wipe clean with dawn/water
3. Carefully remove any fixtures that are not to be painted (e.g.. tail lights, RV ladder, license plate)
a. use envelopes for screws and loose parts, label envelope accordingly
b. remove any caulk entirely from surface (a flat edged razor blade works best)
c. use Goo Gone or acetone to get any residual caulk off
4. sanding the old finish off
a. DA with 180 to smooth chips or filler and to get old clearcoat off
b. sand with 240 grit to get rid of 180 scratches and last of clearcoat
c. sand with 320 grit to get rid of 240 scratches and to smooth out old paint
d. for hard to get spots such as edges, use maroon scuff pad equiv. to 400 grit
The above steps are the most time consuming but how well you prepare the surface for paint will be reflected in the final product. This is not the place to cut corners.Remember any deep scratches from 180 grit or imperfections will be seen in the final paint job.
The header picture is how I plan to paint the endcap. The picture above was what it looked like originally. I used Google’s Magic Eraser tool to make the changes.