Bad body work or ???

tom p.

tom p.

Active member
I've invested quite a bit of time trying to address these "scratches" that cover the hood of my white car. The hood has been re-painted and there are some obvious defects including fish eyes. These scratches are apparent under incandescent light and very low sunlight only. I think I am dealing with car wash damage on other areas of the car and I've had some success eliminating it - - see Presta thread from yesterday. On the hood, however, I'm not so sure what I am dealing with. I'm beginning to think this is poor paintwork repair and these defects may be under the clearcoat. :wall Would a body shop sand the paint prior to applying clearcoat? I am not familiar enough with modern painting processes.







scratch21.JPG




Same photo, contrast altered:



scratch1.JPG






Look how sharp and defined the edges of the scratches are. It doesn't appear to have been impacted at all by hours of polishing.



Thanks.
 
Paint should not be sanded before clearcoat. The only time the paint should be sanded is if you wanted too long before clearing or if you got a run in it. In that case you would sand the paint and paint it again. Probably what happened is that they missed spots where they did body work and didn't sand all the scratches out before painting.
 
well..even if it was a total repaint they may not have sanded it down with high enough grit paper. It takes a while to really sand down clear for new paint and they may have gotten lazy. On most finishes you can use 400 grit wet paper but I know on black you should go no lower than 600 unless you are using single stage paint. It looks like maybe they used maybe 320 or something and paint won't cover those scratches up.
 
Yep, I agree with xtremekustomz, they sure look like flaws under the paint to me too. Heh heh, he's approaching it as a painter, and I'm approaching it as a :hairpull customer. I have some issues like that on many of my repaints, including the hood of the S8 of all places :rolleyes: Sometimes it seems the paint shrinks or something and such flaws show up long after the paint has cured/outgassed/etc. After fretting about it for a while I've just decided to live with it rather than reopen the same ol' can o' worms all over again.



Heh heh, sorry that I recommended that incandescent light....you might not mind 'em as much if you didn't see them as readily. At least it's not one of those colors where such stuff always shows (I know, small consolation..). Is this the Benz?
 
OK, I can cope, thanks. Yes, this is the white MBz, Accumulator. I think if this car weren't white or silver, this condition would be far more obvious. Beleive me, nobody else can see it and I have to look hard and catch it just right. I DON'T want to keep working on it when there's nothing I can do to correct it. The hood looks fantastic, otherwise.
 
It's tough just looking at the picture, but I have seen scratches under clear like that before. Sometimes a bodyshops miss a spot when they repaint clear and don't go back to fix it. It's not common, but it does happen and I have seen it.



First think to do is see if your fingernail will catch onto the edge or take an index or business card corner and go over the scratch and see if it catches.
 
You got sand scratches and the only cure is a repaint. They didn't wetsand the primer/basecoat enough before doing the colorcoat and clearcoat. In other words they painted over a groove in the paint and the paint sunk into that groove and thats what you see. I you don't want to repaint then you can try wetsand your clearcoat and check your progress with a squeegee.
 
Thanks. The entire hood looks like this and you can't feel it with a fingernail, etc. My initial impression, when first noticed months ago, was that it is under the clearcoat. I believe that to be the case based upon my complete failure to improve it regardless of the amount of buffing. If y'all saw it in person, you'd realize it's not really worth re-painting the hood in an attempt to correct it.
 
Tom P.- I find that the passage of time helps with my mindset on this. I tell myself that if I ever just can't live with such stuff I'll let my good guy reshoot it and it's kinda funny...now that I'm sure I can get it fixed *IF I'M WILLING TO GO THROUGH IT* I find excuses to live with it ("Aw, it's not all *that* bad").



At least you don't have something like the M3's solvent-pop :rolleyes: No way around getting the hood of that one reshot, it looks hideous :( The bumper cover has the same sort of stuff that your Benz has, and I'm inclined to just live with it. As you said, it doesn't really jump out at you.
 
well, last quote I had to get a couple of bumper covers re-done was $600 ++ and that kind of set the stage for what I'm willing to live with. Problem is, the other car is going to need to have some previous bad touch work on both bumper covers corrected - - that's far more "urgent".



I feel better that I've made my best attempt at correcting it, so it's time to stop worrying about it. It really isn't that bad...even for an OCD guy.
 
CERTAUTO said:
Wetsanding should take that
Click to expand...



Wetsanding can help if the scratches are in the top of the clearcoat.



Sanding the primer/basecoat with dirty sandpaper will also do that, or not sanding enough with 400/800 after the 220/320 levelling. (Paint will only amplify, not cover, any remaining sanding marks)



Is it like looking at a scratch that is UNDER the clearcoat?
 
I'm quite certain the sand marks are below the clearcoat. I've had no impact on the whatsoever. OTOH, hood is super-glossy following hours of effort ;)



Thanks.
 
Dang....$600 plus to paint some bumer covers. I think I need to move and paint for a living. Although I'm sure cost of living and things like that are just unbelieveable
 
tom p. said:
I'm quite certain the sand marks are below the clearcoat.
Click to expand...

How are you sure about this? I really looks like they used a defective piece of sandpaper before the paint dried. That's a big reason why I wait a few months to sand fresh paint. If it was from poor prep, I think it would look different that this. It really looks like the clear has been cut too deep from maybe even a dirty piece of sandpaper.
 
tom p. said:
The entire hood looks like this and you can't feel it with a fingernail, etc.
Click to expand...

If the re-paint didn't cover/fill the sand scratches, it's pretty unlikely you'd feel it with your fingernail. That's an indication that it's on top of the paint. Did you use a rotary buffer when you tried removing them?
 
David Fermani said:
If the re-paint didn't cover/fill the sand scratches, it's pretty unlikely you'd feel it with your fingernail. That's an indication that it's on top of the paint. Did you use a rotary buffer when you tried removing them?
Click to expand...





Yes, I've used the rotary numerous time. It doesn't appear the condition has changed at all.



Thx.
 
Just found some more on the M3 :( It's like every time one of my vehicles got painted they did the same things wrong. I could rotary away until I hit color and they'd still be there. Adjacent marring that took *many* passes with the rotary/H-T EC/cutting pad/pressure finally came out, but the marks in question are there to stay. Sigh...at least it's not as irritating as the same stuff on the S8's hood.



It seems like they should've either used a finer sandpaper on the primer before the color coat or let the primer sit longer (or both) just as StumpyDetailing suggested. I can't help but suspect crappy lighting, since I only see this stuff under the kind of weird lighting conditions that few people bother with.
 
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