560sl rear spoiler below the bumper

[balsa]

I am repainting my 1986 560sl. I am confused about the rear plastic spoiler that is bellow the rear bumper. The paint on the spoiler looks differently than the rest of the car. The paint color is the same but the surface looks more like a snake skin ... it is not smooth as the rest of the car and as the front spoiler bellow the front bumper.

Is this factory painting logic in order to avoid stone chips from the rear tyres or it should be painted smooth like the rest of the car?

Thank you all for any input.

Balsa

[Roncallo]

Mines nor smooth either. It seems to be some kind of plastic coated steel.

John Roncallo

[page62]

I forget what that stuff is called. Many car manufacturers used it back then as part of the whole rustproofing process. My '79 450SL has it there, and below the side moldings.

[Richard Wooldridge]

Hi there,
My factory manual calls it a "PVC rust preventative coating". It is also under much of the undercarriage. It seems to work well for what it was intended, until it gets a crack in it, then it will trap water next to the metal. Probably a good idea to inspect it occasionally for cracking!

[balsa]

"PVC rust preventative coating" is used on the rear undercarriage only?


I beleive it would be a good idea to paint the front undercarriage in "PVC rust preventative coating" as well?

Any opinions?

Balsa

[Richard Wooldridge]

It's used on the ENTIRE car's undercarriage, and in the fender wells, and on the exterior sides as well under the trim. I did not intend to infer that it was used on the rear undercarriage only, and if you re-read my post you will notice that I did say it is used under most of the undercarriage. That means the entire body, with the exception of the front and rear subframe assemblies, at least on BOTH of my 107s.

[nobby]

The stuff on the rear panel looks like what they call "Gravel Guard" in the bodyshop business. Body shops would offer it as an option to go along with a paint job. The ironic part is, the stuff was great at disguising bad bodywork.
But I digress.

[balsa]

To conclude the plastic area that is bellow rear bumper should be painted with rust preventing PVC coating.The front plastic area bellow the front bumper should have the smooth surface painting.Of course the paint color should be same as the car.

Thank you all.

Balsa