the main thing u need to do is make a place for the paint to stick to. thats why u sand it to form little groves but if u go with to low of a grit u will see it threw your paint. i wouldnt go lower then 220
220 isnt gonna get you anywhere , because chrome is hardened and i mean its hard ..... 220 will only get you fine scratches in the chrome. Use 80 grit with a DA .... trust me after you make a few passes you will realise you cant hurt the chrome. Then after you scuff , get some self etching primer .... then your ready for color ..... paint like normal
D.A. stands for Dual Action.
The disc rotates and oscillates at the same time to prevent creating sanding patterns in the material that you are sanding.
If the primer you use has some filling capabilities then you don't have to worry anyway.
Don't use a belt sander. They are way too aggressive for something like this. They are made to remove a lot of material quickly.
Just have them sand blasted. Blast them good, epoxy primer or some type of etch primer, coat or two of primer surfacer then paint. After you spend the money in sand papers and time DA'ing the crap out of them, it will be much cheaper and you will never have a problem.
if i did it again i would have sand blasted mine. my body shop did a rough sand, medium, light, then adhesion promoter (i think it was some kind of epoxy, then primer, then paint etc... they have held up really well, but road salt left some nick's in the bumper after about 300 miles of driving in the snow. i had it retouched and its good as new, but if you live in harsh winter area's, blast it and be done.
PPG makes a good epoxie primer called DPLF. Use that after you blast them you'll never have an adhesion problem. Most 2k primer will work though. Just make sure you can use it on bare metal without having to etch them.
Chrome plating is only around .0001" thick....you'll be hitting the Nickel underneath it in no time. I would'nt go hog wild on the sanding, just enough to "rough" the surface. Remember to wash with hot water and soap to remove any organic contaminates. Let it dry off good before you paint. Its important to remove organic and residual contaminates for proper adhesion. If you don't have good adhesion, the paint won't last long at all. Hope this helps.
A forum community dedicated to Ford Power Stroke owners and enthusiasts. Come join the discussion about diesel performance, modifications, EGR deletes, troubleshooting, lift kits, tires, wheels, maintenance, and more!