I recently bought a rust free truck box to put on my 01 superduty. It needs to be repainted from its original two tone colors to white and the body shop wants to charge me $80 and hour for four hours to sand the paint lines. I am able to sand them down myself in my shop to save the money but I am unsure how far to sand. Do I sand just to even it out? Or do I take it down to metal?

 

Is the single stripe painted on top of the lighter color? You should be able to feel the lines. Being you are going white you won't barely see anything white hides flawes really well. It is kind of BS that they want to charge you more they have to sand the whole thing with 800 anyway some maybe start with 600 it would take them almost no time for them to level it out. I personally would not go lower than 800. I would probably wet sand it with 1000 myself if i had to do it by hand. Do not go all the way to metal it will cost you more for them to etch prime and seal it then paint it. Just smooth it so you can't feel any difference it should feel totally smooth.

 

In a for-profit shop where time is money sanding that much surface area smooth enough to hide painted-on stripes would be labor intensive---as a former body shop owner that certainly wouldn't be a freebie extra labor thing.

The upside to their charges are IF they make a mistake its on them to fix it whereas if you do it they'll understandably charge you for that same repair.

If final appearance isn't an issue do as Beechkid suggests---wet hand sanding with flexible block using 1000 or even 800 grit should get you close enough. My only concern would be if the final appearance is an issue would the extra thickness of those painted stripes be visible even under the white top coat?

Your choice and money though---------hope the end result is what you want.