LannyL81

I have no idea what to call the area around the trunk when the lid is open; the black plastic that goes around the trunk opening, again when lid is open.
On my new to me '04 Vert, which came from Florida, this area is gray/white...about anything but black.
Curious as to what could have caused this, but also what to do.
I have applied a generous amount of Back To Black, which did not do much if anything.
Any suggestions??...

yellow2007

LannyL81

Yeah...will add pictures tomorrow, too dark now.

LannyL81

Pictures...and this is after I applied the Mother's Back to Black.


Left side

Right side

'Shifter

Hard water?

jdmvette

billschroeder5842

You are going to have to clean it with a firm-ish bristle brush and I'd start with Simple Green. Spray it on, let it soak in good, agitate the snot out of it. Rinse, repeat.

I bet you will see an improvement.

MSG C5

That's pretty bad. I've never seen that before. Thinking hard water as well with some oxidation if the car was parked outside. Below is a pic of my convertible trunk for reference. The OEM finish is more like a gray marble-like finish that really isn't that great. I would suggest removing the rubber trim, removing the struts, prepping the area, and then spray with a multi-purpose Rustoleum or SEM black paint.

LannyL81

OK, I will try scrubbing it with Simple Green.
I do not know what caused this....leak?...although I have washed it and there was no water in the area.
Working on this area has been added to my list.

MSG C5:....yeah I have seen that picture before.....I will be using it as my goal.

c5arlen

My suggestion is to simply leave the C5 with a pro detailer.. He'll fix it, and he needs the business!... It's tricky.. It'll be done correctly.... Just do it!! 😡...this Corvette Looks really bad.

PS.. Replace them struts.

LannyL81

I did a quick scrub using Simple Green, only let it soak for 20 secs and got nothing off. There is not much space to move a scrub brush around, I will need to remove the trunk lid.
A detailer.....it just might come to that!
New struts are waiting on a shelf.

oktx

Maybe try some 3000 grit sandpaper? Just to see if it’s black underneath.

grinder11

I don't think that area is totally sealed in any of the Verts, FRCs, and Z06s. I may be wrong, but note how the actual trunk enclosure itself has its own weatherstripping, and is raised above the area youre talking about. It looks like either hard, calcium laden water stains, or someone waxed it ages ago, and never wiped it off completely. They do make products to remove calcium. We had our CTS get sprayed with lawn sprinklers that used a well for this water in our retirement complex. Looked horrible!! Tried several things that didnt work. We ended up using a chemical that for the life of me I can't remember the name of. It really worked, too. But it's in my Michigan garage, and I wont know what it is until I get home next month. If you have no luck with Simple Green, when I get home, I'll send you half of what I have left for free, just pay shipping. I ended up having to buy more than I needed (imagine that, lol!). That or I'll get the name and PM it to you...

LannyL81

I tried CLR which is supposed to remove calcium, lime, rust.....did nothing.
So I got out some 220 sandpaper, worked one small area...lightly. The sandpaper loaded-up very quickly with a grayish powder and gray/black was beginning to show through...yeah!....it does come off.
Guess this is just mineral build-up...perhaps from a lawn sprinkler....IDK!

In order to really take care of this; remove the trunk lid and remove all the screws for the rear bumper cover and both rear fenders, prop these up a bit so I can get under the body panels as the minerals are there as well.
I am going to put this off until Fall/Winter as this is going to require A LOT of time and will likely have to paint the area as well.

Thanks for all the replies.

Vetteman Jack

Good luck, hope when you begin the repair it turns out great.

RogerZ06

Rub some of those meguiars ultimate black or mothers back to black on it. You gotta work it in.

yellow2007

Whatever it is it has more than likely been absorbed by the plastic so just surface cleaning or CLR won't work. Smart move waiting until fall/winter to address it.

sonicss33

Try some vinegar. You may be surprised.

shovel52

I lived in Florida for a year. We had a nice little auto repair shop. We found stuff corroding down there that never offered to corrode up here in the north. The water is so hard you can see the rocks in it. The air has so much iodine and other chemicals that stuff suffers. The rain is full of other stuff too. I agree with all of the guys here. I am going to put my money on the fine sandpaper and hours of patience. Probably a die grinder and a small buffing tip with some polish compound when you are done. Removing the lid is probably good advice. Good luck. Be sure to lubricate the door hinges....just saying..... Ken

LannyL81

Bringing this back as my Corvette is sitting on jack stands awaiting parts....so thought I would go ahead and work on this area.
Removed the truck lid, that was easy. Started with 400 wet but was not aggressive enough, went down to 150. What I found was there is no minerals here, just the SMC/fiberglass has discolored or the black color came off and the undercoating is showing.
I have gone over the area with 150, just got grayish powder. Next will be 220, then 320, then finish with 400 wet.
Question is, what paint to use? Need to try to match the inside of the trunk lid. Does Chevrolet have a paint name/number for this black? Or has someone found a paint that matches??...that would share the info??

It is anything but cool here in Southern Arizona now, but pretty easy sanding.

THANKS.