It actually depends on what paint you used. If you used the base coat/clear coat polyurethane that is so popular now you can wait as long as you want to color sand and buff {compound] it, or you can do it the next day. I would suggest you start sanding with 1500 grit{wet} to hold down the scratches, and by all means, keep it clean and flushed while sanding. If the 1500 isn't cutting the finish you might drop down to 1200 or 1000 but only where needed. If you painted your truck with some of the epoxy paints like Dupont Imron or Ameriflint you have probabely already waited too long. After these paints cure any sanding will result in scratches that you will think you are never going to get out, that is if you can get the surface to sand at all. If you used a single-stage acrylic enamel you might need to wait a couple of weeks to let it cure from inside-out. Always test sand and compound an inconspicous area to see if the results are what you want before jumping on something like the hood. Clean it, clean it, take your time, keep it flushed and clean it and you will be fine.....lamarb
