BMW New Paint Job - How to treat it?

T

talltorontoguy

New member
Hey all,



My first post!



I've recently had my bmw 535 painted (base/clear), about 6 weeks ago (diamondshwartz metallic, aka really dark metallic grey/black) . I haven't detailed it as I've been waiting for job to cure. I went high quality on both the paint and clear so I'm not worried about it being soft.



As with most resprays, there is some light orange peel in the paint but nothing dramatic. I've read that the way to go after a repaint is to do light wetsanding / colorsanding, then follow the well documented polishing procedure.



I've got both a rotary polisher (which I've used many times) and just recently aquired a PC7424.



I'm nervous about wet/color sanding but could be convinced.



Does anyone have any insight into the best way to go?



Thanks guys!



Rod
 
talltorontoguy- Welcome to Autopia!



For the 90-120 days it takes for the paint to cure, use a fresh-paint-friendly glaze. I prefer Meguiar's #5 but their other "pure polishes" (#3/#7/#81/Deep Crystal Step #2) are fine too. The 3M IHG is another choice but I like the Meg's stuff a lot better. Reapply after every wash.



The paint will be a bit soft for the first few weeks. Maybe you'll want to correct it then, maybe you'll want to wait :nixweiss. I'd probably wait until it hardens a bit. The paper/rotary will cut it anyhow and you'll have fewer problems with micromarring (which can be a problem on very fresh paint).



I myself wouldn't correct the OP, I'd rather have thick clear than thinner (and smoother) clear.



If you decide to wetsand it (and man-oh-man I wouldn't do it for the first time on your Bimmer...) I'd use Meguiar's Unigrit paper (yeah, it really is that much better) and *I* would stick with 3000 grit. 2000 isn't that bad, but the 3K sanding scratches are easy to polish out. Coarser grits cut way too fast for a first-timer anyhow.



Study up on how it's done. Really *study* it; don't just read- actually assimilate and synthesize the information.



Soak the paper in a shampoo solution. Use a sanding block. Inspect after almost *every* stroke. Don't aim for perfection. Hope your painter put on plenty of clear (did he know you were going to sand some off and thus lay it on a little thick?).



But here's one last "don't do it!", I'd live with the OP (as I usually do on my vehicles). Too many people do the wetsanding and then post back here asking "how do I fix what I've done?" It's easy to take off too much.



Yeah, yeah, you guys who've done it successfully are happy with your results. But not everyone is successful at this and the only remedy for a mistake is repainting. There's a good argument that you're only knocking down the high points and thus the sanded paint isn't really thinner than the low spots anyhow...but I dunno...that's assuming a lot of things, especially with regard to technique, and there's still all the subsequent rotary work.
 
Ok... well I'll try the polishing route without wetsanding. I've got 2 other vehicles to do as well (not freshly painted) so I'll experiment on those first!



So now my question has changed to: What is the best polishing procedure (machine/product/pad) to use on new paint that has never been touched? (already cured)





Thanks!



Rod
 
There are a few stages of "curing". At the risk of telling you stuff you already know, let me explain. Long reply follows..



Based on the last 5-6 cars I've had painted (recently, so the technology/paint oughta be current):



For the first few weeks after spraying the paint will continue to harden. It will sometimes (but not always) be *very* soft for the first ~2 weeks. During this time something like Meg's #9 on a finishing pad might even be too aggressive to avoid micromarring. In that case, I'd let it cure for a while and correct it later. But that's a big "if", many paints aren't too soft, you just have to see what *your* paint is like.



After a few weeks the paint will become hard enough that you can use mild polishes like Meg's #80. You can also wetsand without any real worries.



After ~1.5-2 months the paint will get as hard as it's gonna *with respect to the polishing*. It will continue to harden a little over the rest of the curing period, but at this point you can use normal methods/products without much worry.



After 3-4 months the paint will have finished curing. It will be as hard as it's ever gonna get (all the way through) and can also be waxed/sealed at this point.



At 6-8 weeks I'd definitely be OK using Meg's #80, 3M PI-III MG 05937 or similar products. If it needs more serious correction 3M PI-III RC 05933 would be my first choice but the offerings from Menzerna would be good too.



I'd use polishing pads or finishing pads if the polishing ones prove to be too aggressive. I wouldn't use cutting pads myself. I'd probably use a PC/Cyclo as opposed to the rotary at this point, but if you use a rotary remember that it's a lot more aggressive so tone down the pad/product selection accordingly. By rotary, I'd lean towards Meg's #9/finishing pad or maybe Menzerna FP.



You're at the OK-to-polish point, but don't use anything with wax in it yet. Keep using the stuff I mentioned in the prevous reply, it really does take 3-4 months for the paint to truly cure (that's straight from the paint manufacturers).
 
I did a brand new '05 BMW M3 with a black polishing pad and Clearkote RMG and it came out awesome, then I did a newly painted honda after 6 weeks, and used my rotary at 1200 , black pad with optimum polish and it came out amazing.



just my $.02
 
why wouldn't you have the shop that painted your car take care of the orange peel? If you spent the $$ on high end paints I would insist they remove the OP.
 
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