plastic bumper prep

[Eric Giles]

As in my previous post, start with 180, then spray filler primer. Then block sand with 320, and then wetsand with 600 grit before painting. If you don't do the 600 grit wetsanding, you will see the 320 grit fine scratches in your paint.

All of the sanding should be done with a sanding block to maintain flatness.

[E30_(1st Musk)_]

so i should just start with 180. and stay at 180?

[Eric Giles]

thanks guys, i just re-checked this morning. and the bumper dosent have any deep scratches or cracks..it seems like they repainted it. and whatever they used is just flaking off...should i still start with 60 or 180 grit?

DEFINITELY start with 180 grit as the lowest-I should have said that even with deep gouges 80 grit is the absolute lowest you want to go. Anything lower will leave scratches that if not properly smoothed and filled out will show up in the final paint. You might even just want to try 320 as long as it will remove all of the old repaint and properly scuffs up the original.

[E30_(1st Musk)_]

thanks guys, i just re-checked this morning. and the bumper dosent have any deep scratches or cracks..it seems like they repainted it. and whatever they used is just flaking off...should i still start with 60 or 180 grit?

[Eric Giles]

I generally agree with what CK says above, however unless you have very deep scratches or gouges in the plastic, I would not start out with 60 grit paper. Start with 180 grit, fill in any imperfections with Evercoat body filler, block sand again with 180 till level. Then spray a filler primer and block sand with 320 grit. To make sure it is as smooth as possible, do a final wetsand with 600 grit and then paint.

I am by no means a body/paint professional, but I have a good friend that is and I have helped him with a number of jobs-including my E30 in my sig-and this is the process that he had me do on my bumpers.

[ck_taft325is]

60 grit to start it off. Fill any deeper scratches with a feather finsh (a few are mentioned in various threads here), finish with 320 (60 - 120 - 320). Sandable primer (I always used an automotive sandable primer from Home Depot, Lowe's etc etc).

I've never used Duplicolor per se, so I can't help you there. Biggest thing is to make it all straight with a decent body feather finish of sorts, prime and sand (with a palm block, not your hand).

Good luck! Post some pictures up of your progress and/or finish product ;)

[E30_(1st Musk)_]

i just picked up a plastic bumper. but paint is no good. i am going to use Duplicolor gloss black/clear coat...any tips...sanding?etching primer?