Teardrops n Tiny Travel Trailers

I'm getting ready to paint my fenders. They are just fenders right now with no screws drilled for attachment to the frame or chassis. Should I go ahead and paint them now or wait until I know how they are going to be attached to the chassis? Is it ok to drill a painted surface or will that require repainting? I'm assuming that I'll prime the surface with something from the Rust Doctor but I'm not sure if there is some other surface preparation that I should do first. The fenders are steel and in nice condition with no paint on them at all. Should I use something different on the underside than I use on the top?
Thanks.
Kris

Wipe them down with something like lacquer thinner to degrease them prior to painting the primer...prime both inside and outside...are you planning on spraying a finish or brushing? I'm a spray person, spray both inside and out. Whether you paint them now or later and install them depends on how careful you are about working around a finished surface...if it were me...I'd paint them and then not attach them till the very last..drill the mounting holes now, and do a trial fit...that way all you need to do is bolt them up at the end, I had 2 glass fenders painted up sitting in the living room for 2 months...Doug

I'm with Doug!
I propped the fenders on the wheels to get a layout for the holes required. Drilled the holes, cleaned the fenders w/ acetone, primed in/out, painted the outside the finish color, inside, I painted black. I let them sit a couple of weeks while I worked on the galley, then installed them. The waiting period let the finish harden.

Thanks Steve and Doug,
Those are good ideas. I'm hopefully going to get my wheels and tires next week.
Kris

At a paint shp I worked at, we used a product called Pre-kleeno on plastic items that may not be able to handle laquer thinner or acetone. It is specifically made for removing wax and mold releases. I looked at the ingredients and it is naptha and alcohol.

You could drill the fenders after they were painted but you'd have to use a drill bit that cut from the outside in. Something like a hole saw or a forstner bit. It s easier just to drill then paint afterwards.