Itinerant Air-Cooled

The van will finally come out of its winter slumber this weekend. Ya I know about time! I will begin some prep work for the paint job to come in the coming month. Some spots will be sanded down to bare metal to rid it of surface rust. Some spots will be sanded and receive a coat of filler. The van will is parked outside during this process.

What should I do to protect the prepped areas? Do I even need to worry about this? I am thinking that it should be primed in a just over a month.

I'd use a good urathene two part primer. Rattle can primers won't seal the metal from air/moisture penetration and can allow surface rust to form under them. U-pol makes a nice urathane primer that's resonably priced. You do need a paint gun and compressor to shoot it.
I'd find a local auto body paint supply house near you and go discuss your options with them. You don't want to do all the body work and then have rust break though your repaired/repainted surfaces a couple of years down the road. This is especially true in a high humidity area.

I paint with a two part epoxy primer to seal bare metal. Make sure it's really smooth as the primer doesn't sand for sh*t. Then shoot a sanding primer over it.

I was priming my newish front bumper yesterday after sanding in down to bare metal and Osphoing the rusty spots.