Removed paint from rear bumper!

tomhaney1

tomhaney1

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So I'm polishing our BMW 550I using my Makita, a wool Solo pad, and 105. I did the left portion of the bumper, the center portion of the bumper, then moved to the right portion of the bumper. The left and center portions are crystal clear and smooth. After the first pass on the right side of the bumper a chunk literally came off the bumper! I have never seen anything like this in 15 years! Anyone have any thoughts?

Tom
 
Since this is your first post...

Welcome to Autogeek Online! :welcome:


As to your question, I have never seen chunks of clear coat paint come off unless the car in question was already in the late stages of clear coat failure.


I did download and then upload and now insert your photo for easier viewing... it's in your gallery here on AGO


This looks like an isolated problem...

chunkcameoff.jpg




Maybe the paint was impacted in this area?

Have you seen any other signs of trouble with the paint job?


:)
 
Thank you so much for the help!
It made me gun-shy so to speak- something like this makes you lose your confidence and second-guess yourself... It's not just the clear but the entire thickness of the paint! You can see the scratch next to it but, no, I noticed no defect in the area. The front bumper has some minor chips but that's it. I don't want to have the whole bumper sprayed so I'll probably just fill it in and sand/buff it over but now I'm afraid to do that because I don't want more paint to come off...
 
BMW uses plastic bumpers. most modern cars do. These bumpers do not do well with the heat generated by rotarys and the vibrations. Its possible there was some contaminates on the surface of the bumper before the paint was applied and the buffer was able to just rip it right off the bumper. the other possibility is the vibrations and heat lifted the paint of the surface and the buffer then removed it.

a number of things could have caused this. even dropping something on it in the past could have broken the bond of the paint with the surface.
 
tomhaney1 said:
So I'm polishing our BMW 550I using my Makita, a wool Solo pad, and 105. I did the left portion of the bumper, the center portion of the bumper, then moved to the right portion of the bumper. The left and center portions are crystal clear and smooth. After the first pass on the right side of the bumper a chunk literally came off the bumper! I have never seen anything like this in 15 years! Anyone have any thoughts?

Tom
Click to expand...


I posted this a while back...

http://www.autogeekonline.net/forum...eed-polisher/19766-warning-paint-wrinkle.html
 
Thanks for the link :) I was astonished as I have never seen that happen before. I guess I will never use my rotary on a plastic bumper again, which really sucks because that's where a good amount of correction is needed.
 
Was this the rear or front bumper?

If it was the front, is there any chance that the paint was chipped by a small rock on the highway and the buffer just finish taking it off?
 
Sorry, rear bumper. There was no chip, scratch, dent, ding, etc. there. You can see the one scratch that was there in the picture but that area held tight.

I'm ordering some S34A to run with my Flex so I don't have to use the rotary. But I love the rotary :(
 
You know, I just saw where it said on the title of your tread that it was the rear bumper... My bad...
 
Poor paint correction service? Client could have in the past backed up into something and it was either fixed or ruined the integrity of the paint and clearcoat. Like those tiny micro hairline cracks. *shrugs
 
RaskyR1 said:
I posted this a while back...

http://www.autogeekonline.net/forum...eed-polisher/19766-warning-paint-wrinkle.html
Click to expand...


That's a good thread and has good information to help people from making a mistake. I've twisted paint on urethane bumpers before, once on a Viper at a Detailing Class for a Viper Club and luckily, with a little patience and a little light sanding and buffing, I was able to undo the damage.


When I look at this picture,

chunkcameoff.jpg




IT doesn't look like twisting, it looks like the paint in one small area has blistered, the mystery is why?


:)
 
tomhaney1 said:
I'm ordering some S34A to run with my Flex so I don't have to use the rotary. But I love the rotary :(
Click to expand...

Don't be too quick to retire that rotary. You can not have predicted this situation and it'll unfortunately fall into the accident category. Accidents unfortunately happen and they're a part of life. Time to fix it and move on.
 
Mike.Phillips@Autogeek said:
When I look at this picture,

chunkcameoff.jpg




IT doesn't look like twisting, it looks like the paint in one small area has blistered, the mystery is why?


:)
Click to expand...

I was thinking the same thing Mike.

I'm wondering if the substrate was contaminated prior to the paint and clear leaving a poor bond. IF this was the case then I can see a rotary pealing the paint back as shown above.
 
I've had both occur, on a post 2001 BMW nonetheless, also on the plastic bumpers of one of my trucks (Ford). IMO both occur due to heat stress causing the weaker areas of the paint to fail. The small one probably had an impact fracture its underlaying bond with the plastic fascia, and once you get a little heat going... Even using the PC, if the paint is weak it can come off.

The wrinkling is actually a phase change of the paint-plastic interface, causing the paint to "boil" and stretch as it does. If you immediately press down flat on the boiling paint you can sometimes minimize the paint "pull back" that exposes the plastic. Other times it is too late. Either time it is noticeable and will need some repair.

Luckily bumpers are an easy and cheaper area to paint (most of the time) :)
 
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