Metallic Paint Scratch Repair??

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bmwbear

New member
I have two rather large scratches on the passenger’s side of my M3 convertible (silver gray metallic).



My question for the group is how do I blend the repair to match the shininess of the rest of the paint? I have followed the instructions on the repair of chips and scratches here on the site (http://www.guidetodetailing.com/art...p?articleId=27). After building up the paint in several application over a course of several day I wet sanded the paint repair with 2000 grit sandpaper, my problem now is that the new paint doesn’t have the metallic shine of the surrounding paint.



I have Sonus SFX-1, SFX-2, (with matching sonus pads for each), AIO, and some 3M rubbing compound, what would be the best approached to get the metallic paint to match the surrounding paint in brilliance?
 
I dunno how well you'll be able to blend such a repair without having it spotted in (by somebody *very* good) using an airbrush or paintgun. I have some similar scratches on my Byzanz M3 and I know that if/when I touch them up it sure won't look perfect.



To increase the gloss of your current touchups:



Is the touchup paint supposed to have clear over it? Sometimes a basecoat designed for b/c systems won't shine right on its own.



Otherwise, yeah, just polish the area with a good compound/polish. 2K scratches are a bit coarse and hard to do by hand (compared to 3K), but it oughta be doable. There are a scad of different 3M rubbing compounds, some of which work fine by hand, some of which don't.



FWIW, I'd use 3M PI-III or PI-III RC (05933 or [whatever the number for PI-II fine cut is]). I"d follow that with a milder polish. Sorry, not familiar with the SFX stuff.
 
Accumulator said:
Is the touchup paint supposed to have clear over it? Sometimes a basecoat designed for b/c systems won't shine right on its own.
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Thanks Accumulator...



The touch up paint did also come with a small bottle of clear, so you might be right about needing it. The only thing is that the paint the is in the scratch and is built up about the surrounding paint surface blends perfectly in color (except is it raised above the surrounding paint). I bought a rather cheap airbrush (Bager $90.00) at lunch today and also stopped at a Carquest Paint store and talked to the guys they, they seam to think with the airbrush approach there shouldn't be any trouble. I'll post some before airbrush and after airbrush later this weekend.
 
bmwbear- I'd experiment with the airbrush before taking it to the car ;) I used a Paasche airbrush extensively back in the day (plastic modeling) but I've never had the [guts] to use it on anything important on the cars. Well, I did it back in the '70s and it turned out OK, but paints were a lot different back then (single stage stuff).
 
Accumulator said:
bmwbear- I'd experiment with the airbrush before taking it to the car ;) I used a Paasche airbrush extensively back in the day (plastic modeling) but I've never had the [guts] to use it on anything important on the cars. Well, I did it back in the '70s and it turned out OK, but paints were a lot different back then (single stage stuff).
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I plan on doing a lot of testing before even getting close to the car with it. I'm going to go with a very fine and misting spray, I don't want to much over spray and I don't want to have the spray more than 1 inch wide. I'll be sure to let everyone know how it goes.
 
bmwbear said:
I'm going to go with a very fine and misting spray, I don't want to much over spray and I don't want to have the spray more than 1 inch wide. I'll be sure to let everyone know how it goes.
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I'd shoot for an even more narrow pattern than that and I'd do a lot of masking (cover the whole car in plastic sheeting or something) to make sure it doesn't turn into an overspray-nightmare.



There are some big touchups on mine that the previous owner did (you can guess how well they turned out :rolleyes: ) that I oughta redo with my Paasche, but I'm just gonna live with 'em. Well, at least that's what I'm saying for now ;)
 
I recently tried the Touchup 123 system and it might work well for blending that type of scratch. It probably won't be perfect but it should help conceal it. Personally I'd try that before messing with an airbrush and then possibly having to have the whole panel repainted-unless you've done this type of work before.
 
I've been doing touch ups for over forty years. 1) You will not get a perfect "fix" with any color. (White and black come close. That's why I buy black vehicles.) 2) With metallics your "fix" will be even less successful. It's the nature of metallics.



Tom :cool:
 
Hello All..



I have completed the scratch repairs today, and as most of you have already stated matching metallic is nearly impossible. I know that the scrathes are there but I don't think anyone off the street would/will notice them unless they look VERY close.



This is a picture of the biggest scratch after it has been spot filled.







I know this picture is not the greatest quality and is not very sharp, but it will give you an idea of the after.



1. The scratch was wet sanded with 1500 grit wet paper to match the thickness of the surrounding paint.



2. I masked the area and airbrushed the silver metallic base coat over the repair. I allowed it to cure over night then wet sanded the new paint with 2000 grit wet paper to remove any high spots and to also smooth out the paint.



3. I masked the area and did a light airbrush with a clear coat and allowed it to dry for 2 hours.



4. Wet sanded the clear with 2000 grit wet paper to level it and also to feather it with the surrounding clear coat.



5. I then polished out the repairs with Sonus SFX-1 with matching pad, then finally with Sonus SFX-2 with matching pad.
 

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Hey, that looks a lot better! My hat's off to you, both for trying the repair in the first place and also for doing so well :xyxthumbs
 
mixxmstrmike said:
Impressive results!



Thanks for sharing your process.



-Mike
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I would like to thank everyone for their opinions on this project; I would have never attempted it without other people’s suggestion and the online scratch repair tutorial.
 
bmwbear said:
I would like to thank everyone for their opinions on this project; I would have never attempted it without other people’s suggestion and the online scratch repair tutorial.
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Great results!!!



I am working on a scratch now on my Steel Grey 325. I am at the point where I am building up the paint. This may be too much of a scratch for touch up paint, but either way it should look better.



Could you explain you sanding process to level the paint? What # grit? This is the part the concerns me.



Steve
 
SHICKS said:
Great results!!!



I am working on a scratch now on my Steel Grey 325. I am at the point where I am building up the paint. This may be too much of a scratch for touch up paint, but either way it should look better.



Could you explain you sanding process to level the paint? What # grit? This is the part the concerns me.



Steve
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Hey Shicks



I started out with 1500 grit (soaked for at least 30 minutes prior in water with a little car wash added to it also use the water as a lubricant on your work surface), I used an eraser as my sanding block (its small enough and just flexible enough to get into any tight spaces). I wrapped the sand paper around the eraser and used the thin edge to get the painted build up down to where I could just fell it with my finger nail, then I switched to 2000 grit with the same eraser but this time using the thickest edge to feather the rest of paint build up to the height of the surrounding paint, make a two passes with the 2000 grit and check the paint height with your finger nail. Make enough passes to get the paint leveled out.



The next step after you have it leveled out is to buff out the wet sanding marks with your favorite cutting pad/polish and then switch to a finishing pad/polish until you have the clear coat back to its regular gloss.



If you are worried about using 1500 grit off the bat, start with 2000 grit to see what it will do, it might be all that you will need.



Hope this helps..
 
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