M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Exterior => Topic started by: kramerica5000 on September 22, 2007, 09:58:11 AM
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So here's the deal with my car. At some point in its life the hood, driver's side front fender, and driver's side door were repainted, and they did a sh*tty job. The rest of the factory painted panels look completely perfect, but the above panels are faded and have oxidation spots all over them. My hood was looking so bad it looked like a dalmatian. I got sick of it and decided to hit it with some heavy duty rubbing compound and rubbed the crap out of it. After a polish and wax it looks way better. No more spots and the color is much deeper. But its a bit duller than I would like. To get the sheen back, what should I do? Wet sand? should I get an machine buffer?
Update: So I decided to skip wet-sanding, mostly because none of the auto parts stores around here stock 2000 grit sandpaper, but I thought I would see what I could do with a machine buffer. The last time I had polished and waxed by hand, but this time I hit it with a machine buffer and started out with paint cleaner, then machine polished, then machine waxed.
The results are pretty good. The hood is almost as shiny as the rest of the car now and to the point where I can only tell the difference because I know its been worked on. I think wet sanding would have probably taken me the rest of the way, but I think that's too much work considering I plan to paint it once-and-for-all next summer.
Note: I've done the 3 step process before (paint cleaner, polish, wax) and it would improve the color and oxidation for a little while, but as soon as it was out in the sun for a little bit, it looked just as bad again. This time, however, by really cutting into the paint, I think I have reached a stronger layer since the oxidation has yet to return. I've also deduced that the spots were from soap. I think the paint's condition was such that it was porous and the soap was leaving spots (even the windshield soap from the sprayers on the hood). I only use auto soap and I only wash in the shade, but that's how bad the paint is.
So in summary: I was able to take a completely oxidized hood and return it to (almost) like new again by
1. Rubbing the paint with heavy duty Rubbing Compound. This stuff is gritty. It will cut through the paint. I went over my entire hood probably 20-30 times to cut through the oxidation spots. I did it by hand, but I recommend getting a machine to do it. The key is to keep using it until you really cut through the oxidation but be careful not to go too far and cut down to the primer.
2. At this point your paint will be dull with light scratches from the rubbing compound. For a perfect finish wet-sanding may be the best step here. I skipped to thoroughly buffing with a machine using paint cleaner or buffing compound. The buffing compound will remove and/or reduce the depth and dulling effect of the light scratches.
3. Next go over it thoroughly with with a machine polisher. This will bring the shine back.
4. Now wax it for protection.
5. Now enjoy it, because if you paint is like mine, its got issues and will probably look bad again in a few months :-\
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Nice writeup... do you have any before/ after shots that we can check out? I'd be interested to see the changes take place as you performed each step.
Pete
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I should have taken pictures before, but this project kind of started on impulse out of disgust over how my hood was looking, and I didn't really plan on getting so involved with it.
Take my word for it, though, the difference is massive. The hood in general was lighter from oxidation, but the worst were the light colored spots that completely covered it. This wasn't something you had to be up close to to see either. You could easily see them from 10-20 feet away. The disturbing thing was how bad it got over the past year. After my arduous labor, I was able to restore the paint to a darker, smooth consistent finish (though you can still find remnants of the spots if you look hard enough; I could have removed them completely with more rubbing, but it got to the point where I could spot them easily and my wrist was in some pain). The finish is dulled somewhat compared to the rest of the car, but you really can't tell unless you look at it from every possible angle. I think you could make it perfect with some wet sanding, but that is riskier and more work.
In the end, it was definitely worth it for me to loose some shine in order to get rid of some oxidation, and I think overall it looks pretty good. I should also emphasize that it was a lot of work. I probably spent 6-8 hours rubbing the hood over and over again to get rid of the spots. You may not have to spend this much time on it if your hood isn't as bad as mine, but I think that is what's also responsible for the my being able to bring back the original darker color.
While I don't have a good before pic, I'll post some after pics.
Nice writeup... do you have any before/ after shots that we can check out? I'd be interested to see the changes take place as you performed each step.
Pete
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here's my before and after
(http://i104.photobucket.com/albums/m173/kaChris803/SD530987.jpg)
(http://i104.photobucket.com/albums/m173/kaChris803/SD530996.jpg)
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Wow that's what my car is suppose to look like. Thanks for the write up.
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