In-Progress: 1986 Porsche 951 (Guards Red)

[Slowcorrado]

I totally agree RippyD! But it still grates on you a little when it's your car right? :-)

Question time!!!!

I've been having issues where the panels meet with dark "marks" or some type of residue. The clay bar doesn't touch it, the Meguiars #7 doesn't touch it, the Ultimate compound seems to make a dent, but I REALLY have to beat on it. It's almost like the dried deposits that form stalagmites. Brownish-gray, rock hard, satin finish. I'll post a pic below. This is where the hood blend panel meets the top of the front bumper. I've already washed it, used the clay bar, and 2 coats of M7. Does anyone know what it is, and how to safely remove it? Thanks!

Pic of the offending "stuff"

[RippyD]

No idea what that is. Hopefully somebody else knows. I would try some tar remover first. If that doesn't work, maybe acetone or mineral spirits. Lightly and carefully.

[usshelena725]

No idea what that is. Hopefully somebody else knows. I would try some tar remover first. If that doesn't work, maybe acetone or mineral spirits. Lightly and carefully.

As this is an older single stage paint, wouldn't acetone or mineral spirits also take the paint off too? I am certainly no professional, but I would be nervous using those products here.

[RippyD]

Very possibly, hence my lightly and carefully comment. I was thinking a small amount on a q-tip. That was probably a bad recommendation, especially without suggesting testing a hidden spot first. So scratch those and stick with tar remover that's ok for single stage or something else safe.

[Farmallluvr]

maybe very lightly wetsand a spot with 2,000or finer? or maybe a more aggressive compound?
I might be hesitant to use a chemical like mineral spirits or acetone

it seems these days people throw the word Amazing around all the time so I only like to use it when its appropriate and dude......the job you have done on this car is AMAZING!

[Sizzle Chest]

Not sure what that is. May have to up your compound/pad in that area, just watch your paint thickness!

[Gillyz]

You could try just a simple IPA (isopropyl alcohol) wipe down. Shouldn’t be much of a risk at all to the paint.


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[SWETM]

Could it be that the road film that often is oil and petrolium based has stained the paint? One thing that comes to mind is an AIO/cleaner wax or a paint cleaner. Apply it and let it dwell for a little while before you wipe it off. I don't know if #7 contains any chemicals that would desolve the oil and petrolium based embedded contaminants. It's a sensitive area so as Scott recommends get a paint thickness reading and see what you have to work with.

Or could it be that the paint is thin and the primer is showing darker on there.

Do you feel if it's something on there or is it a smooth feeling?

[Slowcorrado]

Thanks for the suggestions! To answer a few of the questions, as a follow-up to the suggestions: I tried an IPA, no change (no damage though) Heh. It seems to be on top of the paint, not really rough feeling, but a satin/dull texture. It looks slightly raised rather than a thin spot. The primer on this car is nearly white, so it's really obvious when you get down to it. The Ultimate Compound does cut it down, but really slowly and I fear for the surrounding paint. I also tried goo-gone (nothing), and Kaboom! (Yes, the tile cleaner as it's excellent on hard water deposits) and it made no difference.

Progress from the last few days:

I've been working on the front end. It's a complex bumper and is of course REALLY beat up from the years of driving and neglect. I've disassembled the turn signals, sidemarkers and some other trim to make it a little easier. After that, it got a cleaning, clay bar and 3 coats of M7. Then, I did a single pass with the UC. Since the bumper is rounded, complex and plastic it certainly shows my lack of experience. I had to do the UC on an applicator by hand to get around the light and air openings and in the grooves. Then I used a smaller (4") pad to go over the rest. It's shining up nicely but there's just too many rock chips and sandblasting to make it truly nice. But, as was mentioned before; this is to be expected and it does look a lot better! I'll work hard to further refine the finish when I get to the polish stage as well. I also polished the fog lights and that made a nice improvement! Before people ask: 1) Yes, I have the original crest to go back on when I'm done. 2) I'll be doing lots of touch-up to reduce the appearance of the worst chips.

On to the pics.

Click the pics to see them in full size/resolution

Before:


After:


Before:


After:

[Dr Oldz]

I’ve seen areas like that above in the body seams. I own/Owned classic cars so I’m kinda familiar with this issue. Usually it’s years of road film build up. I have had luck with products like prep-sol. If not, a compound worked wet with some make shift tool and a terry cloth may work. But work with caution.