Margal

This is second time. That comer by the headlight keeps piling off. What are they doing wrong. I am tired removing and installing the bumper. This is umnitza poly bumper. Any ideas. Do the shop have to strip it to the plastic and prime it again? The shop has to know what kind product to use on bumpers like this I guess or. This guys are quite reputable in this area and I was satisfied with the work overall but this issue with bumper drives me crazy I do not want to bring it to other place as I have to pay. So I am stucked with them now.

turboawd

first off it's spelled "peeling"
i know the oem bumpers come with a primer coating, not sure about the aftermarket. i assumed they sanded and primed it the second time around. hopefully its not the plastic leaching something that causes the bond to break.

Margal

Sorry for misspelling the word. English is my 4th language and I make mistakes
This bumper was primed when I got it. Actually it been painted 3rd time. 2nd time because I cracked it at the bottom. 3rd time due the peeling exact the same spot. Is there anything special I have to know and just to demand It. I do not think they like to spend time on this bumper again and again

Only Bimmers

Margal,

I think sometimes we forget that this is a worldwide forum and people from all areas of the world join to discus their love of BMW's. Please don't worry about misspellings, happy to answer questions.

The reason your bumper is peeling is because it was not prepared properly before painting. No matter what the body shop says, the results speak for themselves. There is no way to fix this except to strip, prep properly, and repaint.

Best of luck with your repair.

KyleB

Looks like whoever painted the bumper didn't wash it to remove the release agent from the panel, and/or didn't scuff the surface prior to applying finish materials, and/or used incompatible finish materials (primer from Brand A, base coat from Brand B, clear coat from brand C) and/or didn't apply an adhesion promoter. in short, the surface likely wasn't prepared properly.

BMW no longer primes replacement panels prior to shipment. They stopped doing that quite some time ago. What you get from BMW is what you'll get from the aftermarket vendors, which is a raw plastic panel. It has to be prepared properly or no paint in the world will adhere to it.

that bumper needs to be stripped and redone.

good luck!

gman6262

And the body shop needs to use a special flexible panel surfacer / primer - so that the paint adheres to the bumper properly, and won't crack and peel when it flexes.

roskinc

looks like pure plastic, paint even took the primer off...they need to add a bumper adhesive like bulldog so it sticks and flexes. bad prep job. i would take it somewhere else next time.

tonyb635

Roskinc is spot on. The bumpers are PP and at the OEM mfg. after they are cleaned they go through a flaming process this etches the surface then the paint is applied. Part so to aftermarket are primed since the body shops would have no access to a flaming process. They make a product call Bulldog and there are several other adhesion promoters that MUST be used, otherwise the paint will depart the scene... I too find its strange that a bod shop would not use this. The bumper I got from Umnitza which comes out of China had a very strange coating on it. It was very weak and when I wiped the preclean on it just prior to painting, this coating started breaking down. If yours had this coating and the shop didn't get it of or all of it off that could be one reason. When the bumper is new and there is no strange coating on it all that is needed is to lightly scuff it with a scotch brite pad, use a preclean, spray 1-2 coats of bulldog adhesion promoter then base and clear. You do not want to use primer, there is no need. for it. To repair this, you will need to use primer (2K) for leveling etc but don't forget the bulldog! Any PP material exposed will need this.

Margal

Thanks all of you for help, seams that they did not do good job. Strange to me that it is peeling same exact spot? There is no paint peeling in other areas of bumper.

tonyb635

Here is some pics of this coating. I can't imagine paint sticking to this at all. Perhaps they didn't get all of it off? Maybe they didn't get the adhesion promoter in this area? It's really hard to say why. You can see in the pic where a little pre-cleaner was on the part and what it did to this coating. The coating totally would break down. Pre-cleaner is required to wipe down the parts just prior to spaying the base coat, so it's not really a strong chemical, but enough to pull any contaminates from the surface.