What causes this defect?

Hi folks, any idea what causes this? It was below the clear coat.

 

Looks like sand scratch under the paint...

I looked at a 73 Challenger last week that had defects like that and the owner was none too happy to hear there was no quick fix...

They are deep scratches usually in bondo well bellow all the other paint work...

 

has that area been repainted? ive seen that on soem cars that had spot paint jobs. thats just my guess tho. im sure some of the pros around here could be of more help.

 

looks like bad prep work/sanding marks :yikes:

 

Very bad prep work.

 

The car has went for a re-sprayed recently. So does bad prep work means it was re-sprayed, sanded wrongly and left those marks when buffed?

I was told that the paintwork was not prep properly before the re-spray process. After it was re-sprayed and experience heat, it will form such mark.. Is there such a thing? :shead:

 

Can you feal the marks?

 

Yes it was sanded wrongly, had nothing to do with the buffing, they were there regardless.

You were told right, I'm sure they used some type of body filler. And who ever tried to "Smooth" it out was inexperienced or blind.

As far as those marks appearing appearing because of heat....The answer is "Hogwash/Bologna" (Someone is being untruthfull to you)

 

Barely.. the surface is smooth. It is like hiding underneath the clear..

Is it possible to reduce or clear them by sanding?

 

No. Basically what happens is the bodyshop uses filler ( bondo ) in an area and then sands it down. They area is then primed with the primer being used to fill in the lines left from sanding and then its painted. Problem is, as the bondo dries, it shrinks and pulls the primer and paint into the sanding lines resulting in what you see? All the body guy had to do was block it out with a finer sandpaper to avoid this mess. Lazy ass! This area will need to be redone at the bodyshop.

 

Too much drinking the night before painting!!:hippie:

 

Bad and lazy prep when sanding the area. Painter probably thought the customer would not notice so why take the extra few min to block the area with a fine sand paper.

I had the same issue when I did some painting on my car bumpers, I didn't sand the are down with a fine grit sand paper and when I put the color base down I was seeing some deeper sanding marks. I had to wait for the paint to dry and re sand the bumpers down to get rid of all sanding marks then was able to shoot the base and clear down.

 

Thx for that explaination! I guess you were right.. The guy that told me the mark was cause by 'heat' did mention something about sinking into the defects. He has been a car dealer for decades so he should know a little from bodyshops. perphap he doesn't have first hand experience in doing so his explaination is a little twisted.

At least now i know what is going on the next time i see this..

 

hmm, for this case, i bet the painter knew but couldn't be bother at all. the car belongs to a dealer and you know, dealer job usually = low pay. I told the dealer to bring the car back to the bodyshop and he told me that, 'you get what you pay' ..lol

 

You know what's interesting, us detailers can only do so much with a finish. I mean if the vehicle had a poor paint job sure we can improve the appearance but it's incredible how important prep work is. Like they say 90% (or more) is prep work the rest is minimal.

I agree with what everyone has said here, not much I can add :shrug:

 

Nailed it. It is sickening how many shops skip steps.

 

Sand scratches. The bodyman must have used too coarse of a sandpaper to sand down the filler (and usually bodyman do, especially if they are on flat-rate)

Then next to blame is the prep guy. He obviously didn't feather it out well enough, and if he was checking, primer usually wouldn't be able to fill that 100% either.

Then comes to the painter, he should have noticed this after, but obviously didn't do anything since it technically isn't his fault.

Then the shop should be to blame for even letting that job go back to the customer.

 

+1...well-said

 

+1....excellent deductive reasoning :applause:

 

Some big Hamfisted guys with a sheet of 200 grit sandpaper using a 2X4 as a sanding block.

Just a guess!!!:shead: