Stubborn Water Spots

[scales4576]

So i'm working on cleaning up an 01 Corvette I picked up a few weeks ago. After washing, drying, and claying I noticed there are some etched in water spots on the flat surfaces (hood, roof, trunk). I thought no big deal and hit it with the DA with an orange pad and ultimate compound...nothing even after multiple section passes. So I broke out the MF pad and M105...only after several section passes was there any improvement. One thing I noticed throughout this is even minor scratches which I could have easily pulled out of my civic's paint with UC and an orange was difficult to get out with M105 with the MF cutting pad...is GM clear known to be really hard? It just seems like it's extremely difficult to remove even minor defects. Any tips? Or should I just keep at it with multiple section passes? I've never had this much trouble before... Thanks in advance!

[Eric@CherryOnTop]

Yes, Corvette paint in particular is known as being some of the hardest paint out there. The thing that sucks is the body panels are made of fiberglass so you can't use a paint thickness meter on them. Since this car is a 2001, you most likely don't know the history of it.

What I would do if I were you is walk around the car and look very carefully at the ends of body panels and the raised body lines for any indication that clear coat is thin. It might be cloudy or white looking in these areas if that is the case. To remove the water etchings and scratches you will need to wetsand them. Start with something like 2500 grit, go slow and take your time. Only do a few back and forth motions before wiping away residue and checking your progress. If 2500 doesn't do the trick, might need to go more coarse. After that, use the M105 and microfiber pad to clean up the sanding marks, then polish and wax.

[scales4576]

Thanks! Yeah I was starting to come to the conclusion that wetsanding was the only reasonable way to get them out...just trying to decide if its worth it since it's not all that noticeable except in very specific lighting

[FUNX650]

Yeah I was starting to come to the
conclusion that wetsanding was the
only reasonable way to get them out...

just trying to decide if its worth it
since it's not all that noticeable except
in very specific lighting
I don't ever recommend wet-sanding
OEM paint---especially so without use
of a paint thickness gauge (PTG)!

•And, BTW:
There are PTGs that measure over
the materials of which Corvette body
panels are comprised. They're a little
costly; but, some are available for a
nominal day-to-day rental fee.




Corvette paint...

The thing that sucks is the body panels
are made of fiberglass so you can't use
a paint thickness meter on them.

Wouldn't the Defelsko PosiTector (200 Series)
PTG, as one example, be a viable solution?



Bob

[Eldorado2k]

I don't recommend wet-sanding OEM
paint---especially so without use of a
paint thickness gauge (PTG)!

And, BTW:
There are PTGs that measure over
the materials of which Corvette body
panels are comprised...a little costly;
but available for day-to-day rental.



Wouldn't the Defelsko PosiTector (200 Series)
PTG, for example, be a viable solution?



Bob

Is your Corvette made of fiberglass? Do you have a paint thickness gauge to measure its paint thickness? Just curious.

[Rsurfer]

Have you considered using a water spot remover?

[FUNX650]

Is your Corvette made of fiberglass?

Fiberglass? No.


Bob

[scales4576]

I don't have a PTG... I am by no means an expert. Most C5 corvette body panels are FRP (fiberglass reinforced plastic) being primarily plastic. Honestly I probably will not be wetsanding it myself...I would rather pay an expert. Since there is some improvement with the MF cutting pad and M105 I will probably just do multiple passes until it is good enough for me (not perfect). I'm not really too concerned about taking off too much material since i'm struggling to get any off at all. Not sure what type of water spot remover you are referring to but these are actually etched into the clear so not sure that would be of any benefit

[Eldorado2k]

Fiberglass? No.


Bob

So it's not made of fiberglass? So only some Corvettes are made of fiberglass? Or what's the deal? School us a bit since you're a Corvette guy...

[scales4576]

They used to be all fiberglass..I think C4s were still mostly fiberglass..but with the C5 they went to FRP which is pretty much just plastic but they add a little bit of fiberglass in the process so they can still say it is "fiberglass" even though it's not

[Eldorado2k]

They used to be all fiberglass..I think C4s were still mostly fiberglass..but with the C5 they went to FRP which is pretty much just plastic but they add a little bit of fiberglass in the process so they can still say it is "fiberglass" even though it's not

Thanks for the quik reply [emoji1417]

[FUNX650]

since you're a Corvette guy...
That's being rather bumptious,
in attempting to pigeonhole,
an automotive aficionado.



Bob

[FUNX650]

They used to be all fiberglass..
I think C4s were still mostly fiberglass..
but with the C5 they went to FRP which
is pretty much just plastic but they add
a little bit of fiberglass in the process so
they can still say it is "fiberglass" even
though it's not
FRP...Not really the whole story:
Gotta dig a little deeper.


Bob

[Mad Wax]

Megs Wheel Brightener diluted 4:1 works better than any water spot remover that I ever used. You just have to be careful and not let it dry on the paint. I keep hose close by or a bucket of ONR soaked rags to wipe up the residue. Just don't use on glass and mind where the over spray goes (trim).

[Eldorado2k]

That's being rather bumptious,
in attempting to pigeonhole,
an automotive aficionado.



Bob

What's the big deal? Do you know about Corvettes or not? I was trying to give you a little bit of credit, but I guess you're way too defensive to accept it.

If you asked me a question about Cadillacs, I'd be more than happy to reply...

Here's a fun fact: Did you know that my current car, the 1997 Seville is the last Cadillac to don the famous Cadillac Crest hood ornament?

https://uploads.tapatalk-cdn.com/20170716/b4dc889b5104375f4ccc8ad7da2f9cc6.jpg

Kinda hard to believe it's been 20yrs. since a Caddy had a hood ornament...