The Laguna Blue car I saw had horrendous orange peel. And someone else in this thread commented that Crystal Red was really bad too.

 

I worked in robotics as a paint process engineer, I even painted parts for the corvette and would like to throw my 2 cents in.

There are many reasons why you could have orange peel. So many that it would difficult list them all. From my experience the main drivers are:

Paint Formulation (not to be confused with paint technology i.e. Solvent vs waterborne)

Solvent Blend

Film Thickness

Oven Temperature Profile

Substrate Roughness (both cured primer and/or part surface)


Wet sanding is the only way to get a mirror finish without causing other serious paint conditions, such as hanging drips or solvent pop. The good news is orange is usually just aesthetic, while the other conditions effect the function of the film.

Brighter colors tend to hide orange peel better, being a metallic has no bearing on whether is helps or hurts OP. That's not to say a metallic can't be better but it can also be worse.

There are differences in how to apply solvent borne versus waterborne but generally those are mitigated through proper paint shop design and paint formulation.

The most likely candidates for OP are substrate roughness or low film build, as all vendors must qualify their paint prior to being used in production. This does not mean that it is not to specification, just that it is on the low end. Either for cost savings or because more film causes other defects to occur which affect performance or increase scrap rate.

This is why it is frowned upon to wet sand a finish as it will lower the film build below the manufacturers recommendation and lead to premature failure.

 

Good stuff Gambit. Thank you.

 

You definitely surpass my knowledge by about 1,000%. Some good information, though much is above my head! I am pretty educated on detailing cars, but the actual paint process (especially at the factory) is way outside my sphere of knowledge!

So what is the solution for people who buy a C7 with orange peel issues? I know you said color sanding isn't the best because you are cutting into the clear coat (which I knew), but I assume there is no other option for people who own these cars other than a full repaint. I have always been told that Corvettes have a particularly hard clear coat. Does this mean it is actually thicker or just harder/more dense?

Hopefully someone at GM spots this (or other) threads and addresses it at the factory so this becomes a non-issue!

 

There isn't a good way really. A wet sand & polish or repaint are the only options.

You can attempt to cheat by light sanding and only applying clear coat but intercoat adhesion would suffer greatly. Either having excessive chipping or flaking (think old glazed donut). This process is not allowed by any OEM or recommended by the major coatings suppliers.

If I was forced to pick. Light sand and polish with the understanding that you are looking to improve but not eliminate orange peel. This will allow some removal and smoothing but not so much as to deteriorate the coating. I don't recommend this for a novice as what I suggest takes a lot of skill and knowledge of how the material will handle abrasion. We spent weeks figuring out what speed, grit, supplier and polish to use. Even after that the success rate was in the 80% range. Of course it all depends on the defect and how severe it is. We weren't just reworking orange peel.

The key is film build but there are no good tools for checking film on plastic. All the tests that are accurate also destroy the part (ie a chunk of plastic is removed and then the paint layers are measured under a microscope).

If the paint was on a metal surface, you would have a chance to guess the film build of the clear but even then it's a guess as all the layers are measured together.

The factory has the advantage of running samples through the line and only coating it with the layer they are investigating. Once it's all cured together it's gets tough.

I assure you they know the film build of each layer but like every plant they will be adjusting their processes so it would be very difficult for them to say your car has X amount of paint. Frankly it's not in their best interest to let anyone know that information for competitive reasons. For example imagine they figured out a way to get great OP while on the lower end of the film build spec. That saves them money while still performing.

Trust me painting is as much of an art as a science even with robots.

 

I have a Laguna Blue Corvette. Perfect paint. I went to a car show last week and was with 4 owners of c7's . All four perfect paint. I think that there are some people out there who have no idea what they are talking about or are trying to stir the pot.

 

The Laguna Blue C7 with the massive orange peel that I looked at was at Club Auto Sport in San Jose, CA two Saturdays ago. I was there in my C5Z, but was joined by a friend who is driving his C6 ZR1, a friend who owns a '71 Coupe and '59 Resto-mod (dare I say Roger has the nicest resto-modded '59 in the country?), among many other non-Corvette guys. This is a Cars & Coffee monthly event. If you are insinuating that I am one of the people "stirring the pot", I am most definitely not. The paint was BAD. I mean REALLY bad.

I went to talk to Roger that day, and asked him what he thought about the Laguna Blue C7 and if he was going to get one (I didn't even mention the paint), and the first thing he mentions to me is how bad the paint is and how he would be out color sanding it. We also nit-picked the chrome accents, but that's for another thread. Overall I love the C7, and even the rear end that most people seem to hate. But the paint on both of the cars I've seen was really bad.

Maybe they were both early production cars? Or possibly they had issues with humidity or something? Next time I will try to see if I can get it in a photo. I was trying to avoid hurting the feeling of the owner of the C7 at the event. Not to mention I am really bad at taking pictures of stuff, but I can try. Clearly I am not the only one who has seen this, and I am not making it up.

If you get Velocity Channel, try recording Corvette Nation past episodes (I assume they replay them). I think it was the 2nd episode where they were highlighting the details of a Torch Red C7 I believe at Carlisle. When they did a close up in on the side mirror, you can see what we are talking about.