I use a Badger in England and I've sprayed all sorts of panels
including complete doors (inner sections usually). I do run mine
off a compressor at 60 Psi which makes things alot easier.

When you do any spraying the final finished is proportional to the
time spent on preparing the job first.

This is what I do -

o    Sand everything flat starting with 180 paper then moving
     upto 360 and finally 800 paper with some water.

o    Undercoat the area using a nice (usually expensive) high build
     pimer filler. Wait for it to harden - usually 30 minutes.

o    Flat the primed area using 1200 paper again with water. Be sure
     not to rub through the primer and make sure you can't feel where
     the primer runs out.

o    Apply the base coat evenly. If you prepared the surface before
     then the base coat finished should be very smooth.

o    Simply apply the clear over the top, 15 mins sounds good to me.
     Make sure you put enough clear on so that there is no "orange peel"
     finish - but be careful not to cause any runs.

o    Polish the clear with some cutting polish - it shouldn't need paper.

Remember the only things you should use paper on is the primer and/or
original surface.

I'm no professional, but I've done a fair amount of spraying.

Hope this helps.

Lee.