Mongo

My 1987 928 S4 that was repainted Guards Red and clear coated at least 12 years ago by the previous owner. Since purchasing the car in 2001, I have been fighting trying to bring the depth back into the paint on the roof. There is a section of clearcoat failure that can be masked with M07 Show Car Glaze. While this is not really a worry for me as I religiously maintain the roof with the glaze after every wash and wax, I am concerned about what look like sanding scratches still.

I picked up a DA G110v2 some years back and I have Meguiars M105 and M205 for correction, but have not achieved any successful results really. I feel like the yellow foam polishing pad may not be abrasive enough to really get the scratches out. M105 is known to take out 1200 grit scratches, but these look deeper, more like 800-1000


From what I can tell you:

1) The marks seen in the picture appear to be deep sanding marks. It looks like an amateur may have color sanded the paint job sometime prior to my ownership.

2) above the driver side door, the clearcoat has failed in a spot about 1.5"x3". Layers of M07, M21 and Gold Class wax make it nearly impossible to tell the clear has failed there.


I would really like to take care of the sanding scratches. I tried taking photos of it again but it's just no hope to get the camera to show it (cheap digital camera). I can tell you that if I were to wash the car off, the areas where the scratches are would look rosy in the sun and not a deep red like they should. This is ONLY the areas that have the scratches.

I have wetsanded before, but only small spots where I have applied touch up paint to great success on my other cars. I don't trust myself wetsanding the roof of my car.

Also, what would be the best way to strip all the layers of wax off that have accumulated over the years when the time comes to correct it? Dawn Soap?? Denatured Alcohol??

Mongo

On a side note, I've been told that this looks like crazing. For some reason though it does not look like the paint is fully cracked and at the same time, why would it happen in sections of the roof and not the whole roof if it really is crazing or checking???

NC928S4

I had similar artifacts on my 89. A buddy at the autobody shop says this is/was caused by paint not completely drying in between coats. He said the remedy is to clear our the old then prime and paint. Painting over will still shows the cracks.

I'm in the process of a re-paint and I have some panels that have this issue and some that don't. Lots of sanding ahead.

Mongo

I figured the roof and hatch would need a repaint sooner or later as there were signs of clearcoat failing here and there. My thoughts were to diagnose the defects first and see if it's correctable by compounding. If the paint defects are due to improper prep and application (in this case the issues in the picture provided), I will have to have the roof and hatch sanded back down to primer again for repaint.

Mongo

More pictures. Not sure if it really is crazing anymore. I hit it with M105 in a small spot by hand with a microfiber rag and buffed it really fast. The paint looks ever so slightly smoother in that area. It does not show up on the camera unfortunately.

Hollisterkiid92

I would try plastic dip, maybe black took and red car can look good?

OTR18WHEELER

It looks to me to be the result of poor prep to the primer coat under the color, which is probably lacquer. I would think a good sealer primer would save from sanding down to bare metal.

Mongo

You guys are right. It is 2:32 am here and after 3 hours of work, no difference. It is crazing alright.

Bummer. Time to start saving for a roof and hatch respray.

jeff spahn

I have similar artifacts and am going to have the whole car painted over the winter when they install the GTS flares.

dr bob

Andy-- Save harder, for a whole car repaint. The crazing from poor previous prep (say that five times fast...) will haunt you forever. And... The red is really tough to match perfectly, and will age differently from the rest of the car. It will end up different colors, especially as you store the car outside (accelerates the aging). You really need to do the whole car, not just the roof panels. Your painter needs to get down to a solid undamaged layer of paint but not through the protection layers. A good painter will know what to do.

Mongo

I had the front bumper repainted by a guy up here who did a fantastic job at matching the color. They used the hood and fenders as the sample to match to. If you look at the car in the sunlight, there is no difference between the old paint and the new paint.

The car is also garaged now and will be forever as long as I own it.

OTR18WHEELER

I used to do professional paint work about 25 years ago, and have been out of the loop of newer technologies, but from what I can see from the pics I have an educated guess that this respray may be from a repair of hail damage, the clear coat is thin and worn from wet sanding and buffing, but the scratches appear to be in the primer below the color, or in the spay filler that was applied under the primer. It probably looked good 12 years ago.

Keith Coe

Another option is to consider a wrap. Did mine in a color so close to guards red as to be damn near impossible to tell.

The Fixer

or handle it this way.

too tough to tell from pics what the exact issue is but positive polishing is a wasted effort.

Tony

X2..no flares going on mine though.

My marks are on the sunroof panel and little areas on the roof and A pillar.
Silver hides them well but in the right light you can see them