Pre-paint question?
Thread Starter
Race Director
Joined: Aug 1999
Posts: 11,126
Likes: 673
From: SE Pennsylvania
St. Jude Donor '03 thru '26
Oldtimer
Pre-paint question?
I plan on wet sanding my C-4 before I take it to the paint shop. But on the top of my back bumper is a 3" starburst of cracks. How do i fix this cracking before i get paint? Do I sand the entire area till there's no more cracks ? Or is there another meathod to dealing with this problem?
Drifting
Joined: Apr 2008
Posts: 1,815
Likes: 10
From: New York New York
It depends on how deep that cracks go. If its in the urethane then you need to use a filler for that or else when you paint it, it will reappear in a year or so. If its just on the paint then wet sand it, carefully, with 320 or 400 until its gone. I am not a body man do don't quote me but that is what I would try first.
Thread Starter
Race Director
Joined: Aug 1999
Posts: 11,126
Likes: 673
From: SE Pennsylvania
St. Jude Donor '03 thru '26
Oldtimer
It depends on how deep that cracks go. If its in the urethane then you need to use a filler for that or else when you paint it, it will reappear in a year or so. If its just on the paint then wet sand it, carefully, with 320 or 400 until its gone. I am not a body man do don't quote me but that is what I would try first.
Le Mans Master
Joined: Oct 2007
Posts: 9,724
Likes: 3,505
From: Akron Ohio
2025 Corvette of the Year Finalist - Modified
2024 C5 of the Year Winner - Modified
2023 C5 of the Year Finalist - Modified
2022 C5 of the Year Finalist - Modified
St. Jude Donor '09-'10-'11
you have to sand evenly all around the area or you will have a divit or ripple in the new paint. If it is only in the paint then yes sand gently until they go away. If you get to primer or another color stop sanding and use filler.
Burning Brakes
Joined: Apr 2009
Posts: 877
Likes: 0
From: Broken Arrow Oklahoma
Use a soft blocking pad. feather the area around the cracks.
Use 600 W/D if your not going to primer . 320 or 400 will leave sand scratches and might show up in the top coat.
If you are going to spot primer (I recommend it) 360 or 400 then sand primer with 600.
Use 600 W/D if your not going to primer . 320 or 400 will leave sand scratches and might show up in the top coat.
If you are going to spot primer (I recommend it) 360 or 400 then sand primer with 600.
Safety Car
Joined: Jan 2004
Posts: 3,783
Likes: 15
From: Northern California
Yes, all cracks have to be removed before painting or they will re-appear again later.
You will most likely have to sand down to the primer or below and the body shop will have to re-primer to fill the area and then block sand until the surface is smooth, even and ready for paint.
Safety Car
Joined: Jan 2004
Posts: 3,759
Likes: 8
Yeah, I would strip it as it could be in the Urethane. You don't know till you take the paint off.
Has it been repainted before?
I plan on stripping my Vette for paint as it has been repainted before, so some places the paint is thick by looking at the deep rock chips. Plus, I have crows feet on the upper driver door. I had backed up and bumped the bumper causing some of the paint to chip off. Whatever the PO used on repaint didn't stick well as I start chipping the paint off with my finger.
Has it been repainted before?
I plan on stripping my Vette for paint as it has been repainted before, so some places the paint is thick by looking at the deep rock chips. Plus, I have crows feet on the upper driver door. I had backed up and bumped the bumper causing some of the paint to chip off. Whatever the PO used on repaint didn't stick well as I start chipping the paint off with my finger.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
5 Best & 5 Worst Corvette Daily Drivers
Joe Kucinski
The Headlights of Every Corvette Generation Explained
Joe Kucinski
5 Best & 5 Most Overrated Corvette Track Packages of All Time!
Joe Kucinski
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
Burning Brakes
Joined: Apr 2009
Posts: 877
Likes: 0
From: Broken Arrow Oklahoma
they are small web looking cracks, it was common when Corvettes were painted with lacquer based paint. It will happen with some older clear coats from the early 90's. this was due to the removal of the UV protection during this time period. If you remember all of the peelers that were driving around then. Some look like it's in the paint but might be stress cracks from age.
Safety Car
Joined: Jan 2004
Posts: 3,759
Likes: 8
I'm thinking maybe it was just a screw up when the PO had it repainted. As in some places, the paint is real thick cause of the deep rock chips. In other place you can tell it is thin.