Bumper polishing

blakjack23 · 03-27-2008, 03:55 PM

I've noticed some stuff on the bottom of my rear bumper that looks like oxidation or something and I'd like to fix it. I've been reading alot of the detailing posts but I just want to verify that I should first use a medium polish to get rid of the problem area, then a mild polish to clean it up, then sealent to finish it up. Is that correct? Sorry if this is a dumb question, I'm new to this and I wasn't sure if working on the plastic bumper was the same procedures you'd follow on all the other paint. Also, I figure the bottom of the rear bumper is a good place to learn how to do this before I tackle the whole car when it gets warmer. Thanks!

BK · 03-27-2008, 05:22 PM

Make sure you clay it first. I think our bumpers are plastic, so I doubt it is oxidation. More likely, it's some sort of contamination, water etching, etc., which might come off with clay. You should clay before polishing anyway, but I'm just saying, what you're describing sounds a little unusual.

As an aside, I'm new to polishing, so take my advice with a grain of salt -- but I think polishing the bottom of the bumper is not the easiest place to start. Assuming you're using 6" pads, part of the pad may not be on the car, making it more likely you'll fling off polish onto places you don't want it. The easiest places for me to polish are the horizontal panels -- hood, trunk lid, roof. The hardest places are the "cramped" areas, where there are lots of body panel creases, or trim in the way. I'd count parts of the bumper in that category. If I had a buffer with 4" pads, I think those spots would be a lot easier.

EDIT - I should add, I've read to be careful about buffing painted plastic because the paint may be a bit softer or thinner there. Also, your description of the steps sounds right -- clean, clay, polish (one-step or two-step depending on how bad it is), then seal or wax.

328i · 03-27-2008, 05:29 PM

Clay should remove it, if not just give it a light polish. Oxidation occurs on single stage paint, and usually more so on parts that get more sun like the hood, roof and trunk.

blakjack23 · 03-27-2008, 05:35 PM

Thanks for the advice BK. I guess I wasn't sure if it was the material under the paint(plastic or metal) or the paint itself that oxidizes. Maybe I'll try to take some pictures tonight of the problem I see and then post and see what everything thinks it is along with the best way to take care of it.

BK · 03-27-2008, 05:38 PM

Quote:

Originally Posted by blakjack23

Thanks for the advice BK. I guess I wasn't sure if it was the material under the paint(plastic or metal) or the paint itself that oxidizes. Maybe I'll try to take some pictures tonight of the problem I see and then post and see what everything thinks it is along with the best way to take care of it.

No, you may be right and I may be mistaken. Come to think of it, I have seen cars with plastic panels that look oxidized, so I don't know. But photos would definitely help.

L~R~G nor cal · 03-27-2008, 06:00 PM

Quote:

Originally Posted by blakjack23

Thanks for the advice BK. I guess I wasn't sure if it was the material under the paint(plastic or metal) or the paint itself that oxidizes. Maybe I'll try to take some pictures tonight of the problem I see and then post and see what everything thinks it is along with the best way to take care of it.

Oxidization is left on top of the clear. The clear is on top of the paint, then primer, then metal/plastic.

Oxidization can be many things, but in short it is just contaminant stuck to your paint. It would also make since that you have it on your rear bumper, because typically that's where I see the most build-up of contaminants.

Here are the steps:
1. Wash
2. Clay
3. Check to see how the clay did, for you might only need to wax depending on how well the clay picked the stuff up.
4. If you still see some stuff imbedded in the paint then you can use a light polish and PC or your machine of choice. Also some cleaners by hand can due the trick, but sometimes can not get it all off.
5. Seal/ZSP (your choice depending on the look and amount of protection you need.)

blakjack23 · 03-28-2008, 01:01 PM

Thanks everyone, I couldn't find my camera last night to get pictures but I did pick up some OTC Meguires clay, paint cleaner and polish. I used it all on one of the spots to see if it was gonna work and it looks like it got rid of the trouble spot(which there are more of). My car does have swirling and marring too so a full exterior detail is definitely needed. After a little more research, some more purchases and some warm weather I'll get it done.

03-27-2008, 03:55 PM	#1
blakjack23 Major 37 Rep 1,074 Posts Drives: like a bat out of hell Join Date: Feb 2008 Location: Minneapolis, MN iTrader: (3) Garage List '06 325i [0.00]	Bumper polishing I've noticed some stuff on the bottom of my rear bumper that looks like oxidation or something and I'd like to fix it. I've been reading alot of the detailing posts but I just want to verify that I should first use a medium polish to get rid of the problem area, then a mild polish to clean it up, then sealent to finish it up. Is that correct? Sorry if this is a dumb question, I'm new to this and I wasn't sure if working on the plastic bumper was the same procedures you'd follow on all the other paint. Also, I figure the bottom of the rear bumper is a good place to learn how to do this before I tackle the whole car when it gets warmer. Thanks!
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03-27-2008, 05:22 PM	#2
BK Smiling politely 179 Rep 7,931 Posts Drives: 330i Join Date: Feb 2006 Location: Washington DC iTrader: (0) Garage List 2006 330i [9.00]	Make sure you clay it first. I think our bumpers are plastic, so I doubt it is oxidation. More likely, it's some sort of contamination, water etching, etc., which might come off with clay. You should clay before polishing anyway, but I'm just saying, what you're describing sounds a little unusual. As an aside, I'm new to polishing, so take my advice with a grain of salt -- but I think polishing the bottom of the bumper is not the easiest place to start. Assuming you're using 6" pads, part of the pad may not be on the car, making it more likely you'll fling off polish onto places you don't want it. The easiest places for me to polish are the horizontal panels -- hood, trunk lid, roof. The hardest places are the "cramped" areas, where there are lots of body panel creases, or trim in the way. I'd count parts of the bumper in that category. If I had a buffer with 4" pads, I think those spots would be a lot easier. EDIT - I should add, I've read to be careful about buffing painted plastic because the paint may be a bit softer or thinner there. Also, your description of the steps sounds right -- clean, clay, polish (one-step or two-step depending on how bad it is), then seal or wax. __________________ E90 330i Black Sapphire 6MT \| 991.1 C4 Platinum Silver 7MT
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03-27-2008, 05:29 PM	#3
328i Colonel 153 Rep 2,934 Posts Drives: E46 ///M Join Date: Jan 2007 Location: central NJ iTrader: (15)	Clay should remove it, if not just give it a light polish. Oxidation occurs on single stage paint, and usually more so on parts that get more sun like the hood, roof and trunk. __________________
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03-27-2008, 05:35 PM	#4
blakjack23 Major 37 Rep 1,074 Posts Drives: like a bat out of hell Join Date: Feb 2008 Location: Minneapolis, MN iTrader: (3) Garage List '06 325i [0.00]	Thanks for the advice BK. I guess I wasn't sure if it was the material under the paint(plastic or metal) or the paint itself that oxidizes. Maybe I'll try to take some pictures tonight of the problem I see and then post and see what everything thinks it is along with the best way to take care of it.
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03-28-2008, 01:01 PM	#7
blakjack23 Major 37 Rep 1,074 Posts Drives: like a bat out of hell Join Date: Feb 2008 Location: Minneapolis, MN iTrader: (3) Garage List '06 325i [0.00]	Thanks everyone, I couldn't find my camera last night to get pictures but I did pick up some OTC Meguires clay, paint cleaner and polish. I used it all on one of the spots to see if it was gonna work and it looks like it got rid of the trouble spot(which there are more of). My car does have swirling and marring too so a full exterior detail is definitely needed. After a little more research, some more purchases and some warm weather I'll get it done.
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