i had both bumpers on my 300e painted body color for the monotoned look. well the paint on my bumpers is begining to lift and peel off. the paint job is still under warranty so i will take it back to complain but im thinking since these bumpers on these early 124s didnt come from the factoy painted could this mean that the surface on these bumpers arent designed to let paint adhere to them. one other posible reason could be before the paint job i used those back to black dressings for the bumper to keep them looking new. could it be that the paint shop didnt prep the bumper before repainting and there was still silicone left from the bumper dressing.

they probably havent sand it very well.

If there were some silicone on the bumper you should have seen it after the paintjob.

Roald

The shop probably didn't do a good job. I've had bumpers painted before and was told careful prepping was required along with the appropriate primer. You can't paint it like you paint steel.

The only problem with painting bumpers or other plastic panels is that you can't take it back to stock as the prepping and sanding destroys the original finish.

If your shop can't do a decent job, it might be worthwhile to ask around. Then check their previous work before committing.

It can be done...and done well....

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The stuff you applied to your bumper has nothing to do about it. The first step in prepping the bumper is cleaning of the film and sanding it down to a new surface. By sanding it 100% of that film stuff should be completely removed. The reason for the pealing could be multiple problems such as: not sanding the primer paint smooth enough, not cleaning the surface well, and an uneven mixture of paint product could lead to your problem.

I had my bumpers done with the aid of my dad and it came out real good. Right now the only problem I have is those little chips from hitting oncoming rocks.

When painting plastic and rubber parts, good shops add a "flexing agent" to the paint. This gives the paint a "rubbery" quality, so it can conform and deform to the movement of the surface it is adhering to. Metal is more rigid, so those qualities are not necessary for paint in those areas.

Even if you prepare the surface properly, you will continue to experience "spiderwebbing" or "flaking" unless the paint is properly treated. This is not as big a problem with the harder plastics, but the soft plastics like rubber moldings have a larger expansion rate, and are more prone to the problem.

BTW, the one way a surface can be resistant to rock and debris chips is by powder coating. That process however is electrostatic (requires a conductive surface), and thermal. The temperature of the baking process would melt the plastic pieces.

The other is to use Imron (a Dupont product). It's widely known as aircraft paint. Extremely durable, but difficult to apply, and even more difficult to remove if you screw up...I've had metal engine tin pieces that were subject to a lot of dropped tools, etc. painted with Imron, and they held up extremely well.

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I think the key here is that the impact strip on the 1986-1993 124 Benz (which come only in black) are a different material than the impact strip on the 1994-1995 Benz.

can someone post a total price of what it would be to get the plastic prepped and painted by a pro. thanks.

- Philip

Everything could be painted, doesn't matter how soft is the material... G-Benz is correct, the secret is the flexing agent.

Four years ago I painted the bumpers from my 300E and their look as new till today.

The bodyshop where I painted them is a STANDOX dealer and they have all the neccesary primers to treat any type of surface.

Before they paint my car I was very concern about how long the paint will last in good shape. To make me feel confortable they painted a rubber ball and a sponge with that treatment, two days after they painted those things I was able to squeeze the sponge and bounce the ball and the paint was immaculate.

Make sure the body shop you choose know about those kind of treatments.

Good luck !

Does anyone know what this flexing agent is and how to get it? I was just going to get some paint from Tower Paint - they'll put it in spray bottles for you. I don't know if they know or care that I am painting the bumper and put a flex agent in there.

Any supplier that sells automotive paint should have the flex agent as well. If you tell them what you are using the paint for, they should point you to the product you require. It comes in its own can and has to be mixed in with the paint just prior to application. Follow instructions as to mixing ratios to get the best results.

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2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car