I have a '71 250C and the paint could use some work (dark blue, non-metallic) and I'm sure this isn't the original paint. I don't think she's ready for a new paint job though, so I searched previous topics and found almost too much information. There is your obvious oxidation, water marks in the paint, etc., so I tried using rubbing and polishing compound on a small section and the results were better than I thought. Problem is that it's very slow-going. I have read about the absolute plethora of techniques and products on this site and I guess I need to make sure I'm going about this the right way because I haven't seen rubbing or polishing compound mentioned yet! Somebody please steer me right before I do something I regret.

The rule of thumb in detailing is to always try the least agressive methods first. It may very well be that you need to use rubbing compound on your paint due to its age and heavy oxidation but, I would try something a little safer first. Rubbing compounds have abrasives in them that act like fine sandpaper. You are actually removing paint when you use them. However, if the paint is really bad you may need to remove some of it.
One thing is for sure, you need a good buffer. There's no way I would tackle this job by hand. Another thing I would highly recommend is to click on the Meguiar's banner at the top of the page and get their recommendation.
If it was my car I would try Meguiar's #7 applied with a good orbital buffer, removed with terry toweling and then followed by Clay Magic lubricated by Meguiar's Quick Detailer. If everyhing looks good at this point then seal it with a good coat of Meguiar's #26 Hi-Tech wax. If not, then try a Meguiar's Fine, Medium or Heavy-Cut Cleaner until the paint looks good. If all of this fails then you need to repaint.

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Bill Wood - Webmaster
MercedesShop.com, LLC

wjbell,
As Bill said, it is best to try the least aggressive first. However, based on what you have described so far the most logical step would be to start with Meguiar's Mirror Glaze #9 "Swirl Remover". It is for removing the lightest of scratches (swirls, hence the name) and is safe for just about any finish. Another point to mention is that it is better to apply something less harsh several times than something too harsh once. I've found excellent results using multiple apply/remove cycles of #9 on even acid rain damaged paint. #9 removes so little paint that it takes several applications to be effective against the real deep stuff. Another good thing is that you can treat the car as a whole with say 2-3 application cycles then spot treat specific trouble spots as needed. You can even put a dab on a (clean) fingertip and work it in that way. I would try multiple apply/remove cycles of #9 first.

From there we clean what is ON the paint. This means clay. Since you have searched the shop forum archives you should be up to speed on clay use, brand recommendations, etc. If not, let me know and I'll take care of it.

The #9 has removed stuff IN the paint and the clay has removed what is on the paint. From there it is time to spruce up pure looks. Apply Meguiar's Mirror Glaze #7 polish and remove. Keep up the apply/remove cycle until you are no longer getting significant amounts of black residue on the removal rag. It should look similar to the color (dark green) of when it was applied. #7 removes no paint and really really shines up the finish.

Once you have #7'd the car it is time to protect all your hard work with some wax. At that point I'd recommend either Meguiar's Mirror Glaze #26 or Meguiar's Gold Class liquid wax. It is close between them, but the Mirror Glaze might just get my pick between the two. Apply remove and you should be (worn out!) and really be seeing a huge difference in the appearance of your car's finish. If you have any other questions please let me know. Most of the steps above can be done with an orbital buffer but one is not necessary provided they are done in the order outlined above. A buffer will make it a bit easier, but not a whole lot quicker. If you do go with a buffer, Porter-Cable aka Meguiar's buffer, is the one to go with.

Hope this helps...Lee

Thanks for everyone's input! I would feel better about not using the rubbing compound and your advice convinced me. Thanks again for all of your help and I'll let you know how it turns out!
Jason

Well, the water stains are deep, very deep. They're not even stains really - more like hard water crusts that are really one with the paint by now. The entire hood is covered with these, so it was slow going. I went through 10 applications of #9 and the spots are only about half gone (by hand, orbital buffer, the works!). Also, there are pin-head sized bumps in some areas that really take some elbow-grease to remove - is this severe oxidation? I'm afraid that the #9 just isn't strong enough to handle this type of damage, so I'm thinking again of prudent use of rubbing compound - at least to remove the surface crust. Please advise!

You can try something harsher to spot-treat the worst areas but you then have to go over those spots with #9, then #7, then wax to get them "back to good". Another thing to consider is that though #9 does remove paint, it removes only the most minute amount of paint. Think of it like a rag that cannot absorb but a very very small amount of water. That is why multiple light-scrubbing/buffing action apply/remove cycles work much better (and are much easier on the shoulders/arms/back/hands/etc) than less apply/remove cycles of more intense buffing with #9. For those raised feeling spots, get a clay-bar. You will be amazed at its action once you've been over the area once or twice with #9. The meguiar's bar is good but seems biased towards a finish that is already pretty clean. For revival work I've found Clay Magic works pretty well. BTW, do not use the spray lube that comes with the Clay Magic bar unless you want to be chasing streak marks for a good 4 hours per panel. Use liberal amounts of Meguiar's #34 aka "Quck Detailer" spray with the Clay Magic bar. That combo seems to work the best on rescue/revival/restoration cases once you've been over an area with #9. Give the above a shot and let us know how its working. Depending on how it goes, we can take it from there.

Hope this helps....Lee

The clay made no noticeable difference. I finally bit the bullet and tried a very fine polishing compound on an orbital buffer. The deep water marks are barely still there, but the surface roughness/crusts are gone and the surface is glass smooth without any swirls or paint damage. I figure I'll do another pass with #9 for good luck and move ahead with the rest of the plan! I had my fingers crossed the whole time and it looks like my gamble may have worked, but I guess I won't really know until I'm completely done. I still agree with your previous comments, though, that the polishing compound was a last resort for a desperate situation where all other options failed (just in case someone reads this and jumps right to it!). I'll keep you posted...

[This message has been edited by wjbell (edited 01-26-2000).]

Just a thought - if the droplets are lime deposits, vinegar, or very dilute muriatic acid (hydrochloric acid) may help. I'd try it on a rag on an inconspicuous area. If you see bubbling, that's carbon dioxide gas as the vinegar dissolves the stain.

I found out that the car was hit by sprinkler overspray for a year as it baked under the Arizona sun! I've come to learn that there's nothing worse than hard water. I'll try the vinegar idea and see if it works.