How to remove this stuff under my bumperettes?

[Tommy Z]

Happy Saturday all, Trying to replace the original beat up US spec bumperettes on my 79' SC and I can find anything in my shop that will remove the old crud beneath. Feels like some sort of cosmoline type substance. A little disappointed at the condition of the paint underneath but too late to turn back now. If I can get this hard plastic feeling coating off it will go a long way to making the swap worth while. Any help would be appreciated!

[EC900]

I’m wondering if it’s just build up of wax or clear coat from any previous respray(s). What I see i don’t think it’s cosomline as there’s no need for it on/under painted aluminum bumperettes. I’d try warming the substance a bit to eliminate the cosmoline theory, which mineral spirits, wd40 would get it off with some work. If it wax or wash residue (white-ish is what I see in pic) it can probably be worked off with some griots correcting polish.
If it’s overspray, the polish will remove but may need more aggressive approach. A touch or swab of denatured alcohol on it in aninconspicuous place can help determine if it’s a paint related substance. That said, try working on the surface that will be covered by the new bumperettes. Maybe even some 1000 grit wet sanding and see if that gets any results, seems you want to clean up the edges so this white-ish stuff isn’t visible.

[porsche930dude]

hard to tell from the pic but its probably the clear coat peeling

[DaytonaCoupe66]

I realize it's a matter of personal taste, but the Euro bumperettes can be had for similar $$$ as the NA variants, and are lighter. If you're changing them for new ones consider Euro. It's an easy project to remove the bumper, plug weld the no longer needed holes, and respray the bumper.

[917_Langheck]

Looks like hard water deposits. Try some CLR or hot distilled vinegar.

[NYNick]

Nail polish remover on a Q-tip. Worth a shot.

[Cairo94507]

Goof Off?

[Flat Six]

Originally Posted by porsche930dude

hard to tell from the pic but its probably the clear coat peeling

FYI, if it's original paint, should be single-stage -- no clear coat.

[David Inc.]

Really hard to say from the photo. I might try getting it with a clay bar, maybe goof off.

Originally Posted by DaytonaCoupe66

I realize it's a matter of personal taste, but the Euro bumperettes can be had for similar $$$ as the NA variants, and are lighter. If you're changing them for new ones consider Euro. It's an easy project to remove the bumper, plug weld the no longer needed holes, and respray the bumper.

Can you share a source for these? I put my car back together and my US bumperettes are little better than trash. Definitely considering going with the Euro but don't want to spend $$$.