What is going on here?

[suprajay79]

My 2007 Z06 came with a small spot on the hood. No big, I can fix it. Okay, maybe I can't. One year later. That spot is now stretching across the hood to form a long line.

Car has been garaged most of its life, with the exception of the past two months. The spot started growing after a) June and b) when I started using Wolfgang Fusion. I doubt the Wolfgang has anything to really do with this, so I'm leaning more toward an environmental issue.

Here at Vandenberg (where I have been TDY for two months), I have no garage to use. In the mornings, dew sticks to the car like no other. I also walk out to the car to find that the underhood liner has somehow left an impression in the dew on the hood.

This line, and another line that is also starting to form, follow those lines on the hood exactly.

I'm guessing it's something to do with the heat of the hood interacting with the wax, paint, clear coat, and moisture on the paint surface. Has anyone seen this? Is it scratching, marring, or is it some sort of paint anomaly caused by poor paint practices in Bowling Green?

I need answers, and have no where else to look. I tried uploading one more image, but I have to return to class and will follow up after. Thanks in advance!

 

[Mike PhillipsMike Phillips is verified member.]

Here's your picture. I uploaded it so it can be "inserted" instead of attached, makes it easier for anyone to see it.

Couple of comments....

If this is the factory paint then the issue is probably topical, not under the clear. How deep the stain penetrates is anyone's guess.

If the product you're using are not staining the entire hood then they are probably not causing this stain either. If they are then there's something wrong with the paint in this area and not the rest of the hood otherwise it would not be affected.

For things like this I do what I call troubleshooting.

Here's how you troubleshoot an assumed topical paint defect.

Place a tape line across an affected area and then ONLY work on one side of the tape-line and LOOK to SEE if you can fix one side by using a compound or polish on it.

The idea being if the defect is topical, that is on the surface and you abrade the surface you should be able to remove the defect.

If this doesn't work then it probably means the defect, or in your case some type of staining, goes DEEP into the clear and thus abrading the surface just exposes more stained paint below the surface.

Clearcoats are NOT very porous so it's really hard for any chemical to penetrate "into" the paint.

Not sure what else to say except if you can improve the area that you buff on then remove the tape and buff on the entire thing using either a compound or a polish.

Hopefully this will remove the defect.


:dunno:

 

[Setec Astronomy]

The "impression" in the dew from the hoodliner indicates areas where there is a temperature differential from the insulating properties of the liner. If there is no dew in that area, I interpret that to be an area of less insulation which is allowing engine heat to warm the hood, so the dew won't form.

Presuming I figured that all out correctly, and the "spot" is in the place the dew isn't forming, would then lead to the conclusion that the spot on the hood is being exposed to more engine heat than the rest of the hood (during operation).

How that helps you fix the problem I'm not really sure. Some waxes have a darkening effect, and it may simply be that, and that said darkening effect is more pronounced in those heat-affected areas due to changes that have occurred in the paint.

Having said all that, following Mike's suggestion of taping off and polishing should help you--either you're going to make the spot look like the rest of the paint, make the rest of the paint look like the spot, or it's going to stay mostly the same.

 

[suprajay79]

Thank you both for the advice. I'm making a trip home this weekend and plan on pulling out the big guns to try and see if I can improve this spot.

The tape idea sounds like a solid plan. I've never seen defects like this before, so I'm hoping I can polish it out. If not, I'll update with more pics and see if my troubleshooting leads to any conclusions.