I did a search about painting toolboxes and came across one about diamond plated... but my question is: my grandpa gave me an extra cross bed toolbox. I would like to paint it black to match my truck and take my big job site box out of my truck so i can use the bed a little more. what can i do to prep it so the paint will stay?

 

lots of sanding. probably with a 180 grit paper. and several coats of paint

 

my post was probably the one you found. i tried using 100 grit paper...it ate through the paper and my fingers way too fast. then i got a scotchbrite pad...dont know how coarse but it was pretty coarse. it takes a 10th the time with a ton less effort and wear and tear on your fingers. then i primered it with automobile primer, i forget the brand, after two coats of that i sprayed on duplicolor's truck bed coating,probably 5 or 6 coats(2 whole cans). the stuff is amazing..it gives it a great texture, plenty scratch proof, and a great shade of slightly gloss black. i have pics in other threads ive posted and pics in my gallery

 

If it's aluminum,there is a acid etch prep you can use prior to primer & paint.