[tcl]

Can anyone who works in, or has knowledge of the industry briefly explain how today's GM vehicles are painted? How much is done by robotics? How many layers of what are shot? How is the paint cured? What type of quality controls are in place? Lastly, given the unusual shape of the Solstice (e.g. the protrusions on the trunk), do you think the process will be more complex for it?

 

[brentil]

This doesn't necisarily answer your question, but it's kind of relivent. I don't remember which car company it was, but there was a special on Speed recenlty and they showed the paint process the company did. They main body went through on a conveyor system into the paint room where it was primed by a robot, baked, painted by a robot, baked, then clear coated. I don't remember if the clear coat was baked or not too. All of the misc panels,parts (doors, hood, trunk, etc) went into a similar system but were hung from an overhead system, and pretty much went through the same process. Then someone assembles them afterwards.

Was kinda cool to watch.

 

[SolsticeMan]

TOMDOC may be able to help here (thought he worked at Wilmington) - assuming it's not secret, and he won't get in trouble.

Many paint systems today actually do just about all the painting with no people present at all - at least in the application areas, which are fully sealed, filtered, and pressurized areas.

The reason for this is simple: the majority of paint problems are due to debris in the paint. The main source of debris is human traffic in and out of sensitive paint areas.

Eliminate the people, and you eliminate over half of the problems associated with painting a vehicle. Robots also cover better and usually have less oragnge peel because the application rate and sweep rates are very consistent - unlike human painters, which have more variation in application head sweep speed, and have a tendency to try and "fog" or "feather" at times (partially apply the paint or over-apply). Robots don't have to go to the bathroom, nor do they get progressively tired toward the end of shift - and Mondays, Wednesdays, and Fridays are all the same to a robotic painter.

However, Wilmington Assembly may or may not be this sophisticated.

 

[Brian]

Also, I would bet that it is a bit healthier to have robots spraying paint then humans. Got to keep those healthcare costs down :smile

 

[fred96ws6]

Robots also cover better and usually have less oragnge peel because the application rate and sweep rates are very consistent

Well GM must have some old tired robots because GM cars have some of the worst orange peel of any of the automakers. Even the new Corvettes have some orange peel on them. In one commercial where they show a close up of the side of a new G6 you can see the horrible orange peel on it.

 

[tcl]

Well GM must have some old tired robots because GM cars have some of the worst orange peel of any of the automakers. Even the new Corvettes have some orange peel on them. In one commercial where they show a close up of the side of a new G6 you can see the horrible orange peel on it.

I've been conditioned to accept some peel, but not to the point where you can notice it from 15 feet away. I will say that I had a 2001 GM car with almost no trace of it. It had better paint than a lot of high end cars I've seen.

The main thing that puzzles me is why this aspect of paint quality seems so inconsistent, even between several vehicles of the same make, model, and year. That's why I asked the question about quality control processes.

 

[SolsticeMan]

Well, orange peel is a difficult thing to do today - some of it comes from the lower and lower amounts of solvent and carrier allowed to be in the paint - higher solids (better for environment, worse for paint application) make it difficult to particulate the paint properly, the result being "blobs" or inconsisent fog density patches forming in the application spray.

Inconsistent sweep speeds also contribute, as well as inconsistent air flow in the vacinity. My understanding is using a programmed robot in a human-less environment, you can accomplish three things that should reduce orange peel:

1) consistent and accurate sweep speeds,
2) closer nozzle distance, reducing the tendency for the paint fog to become turbulent, and
3) less random air movement, 'cause there's no humans entering and leaving the area all the time.

I'd be willing to bet that Wilmington is doing everything they can to have the best process possible - and an unmanned environment is an important step here.

 

[tcl]

Solsticeman, thanks for the explanation.

 

[2KWK4U]

Isn't it true that orange peel can also be contributed to humidity and barametric pressure? I've heard that you always want to shoot paint when the barometer is rising, and not when it is falling. This shouldn't be as much of a factor in a sealed environment though. But it could explain inconsistancies among the same year, model, and paint codes.

 

[AeroDave]

Robots are more consistant than humans, but if no one is paying attention to what they are doing, and do not maintain them or routinely check their adjustments, they can produce awful paint jobs. GM's problem is not paint application equipment, it's quality control. They have the tools, they just tend to be sloppy with them. That's why you can find some GM cars with great jobs and others with the Earl Schieb treatment. I have a feeling that GM hates to repaint or scrap parts that are poor quality, and so sends them out and hopes no one notices. Problem is, we do.

Is it just me, or does it seem like the lower the cost the car in the GM stable the better the paint, and the more expensive the worse it gets? It seems like Cavaliers get better paint jobs than Cadillacs. The new Cadillacs seem to be a hit, but their paint jobs have a ways to go before they are "The Standard of Excellence".

 

[Chip]

I used to work on the Reynolds Metals Automotive team as we tried to assist the big 3 use Aluminum for hoods, fenders and trunk lids. Over the years there have been many approaches to applying paint. The first concern is the carrier. Some used a solvent carrier, but increasing state & federal regs. made them try new means of delivery. When the last Blazer came out in 95 Chevy used a fine water spray (with other agents) to deliver the paint. I've got a 95 Blazer and the paint seems to have held up fine. After a vehicle is painted it goes through a paintbake cycle whose duration varies from plant to plant and company to company. It is usually around 30 minutes in duration and the body is subjected to temps. of 300-375 degrees. 6061 aluminum body panels actually gain strength during the paint bake cycle. The metal is in a T-4 temper during stamping then is brought up to a T-6 temper as a result of the paintbake cycle. Steel gains no such increase, but does not need it anyway.

 

[Fformula88]

Well, orange peel is a difficult thing to do today - some of it comes from the lower and lower amounts of solvent and carrier allowed to be in the paint - higher solids (better for environment, worse for paint application) make it difficult to particulate the paint properly, the result being "blobs" or inconsisent fog density patches forming in the application spray.

Inconsistent sweep speeds also contribute, as well as inconsistent air flow in the vacinity. My understanding is using a programmed robot in a human-less environment, you can accomplish three things that should reduce orange peel:

1) consistent and accurate sweep speeds,
2) closer nozzle distance, reducing the tendency for the paint fog to become turbulent, and
3) less random air movement, 'cause there's no humans entering and leaving the area all the time.

I'd be willing to bet that Wilmington is doing everything they can to have the best process possible - and an unmanned environment is an important step here.

Welcome to environmental standards! They make it very difficult to achieve a really great finish because of teh lower amounts of solvent and carier allowed in paints.

I've noticed bad orange peel on a lot of different cars made in our country. Anything from GM products to Honda's. Check out a US built Civic. Its just as bad as a Saturn Ion in paint quality! I suspect there is also a cost cutting factor on some of these cars too. No automaker will put a show quality finish on what is essentially an economy car.

Since Solstice is a sports car, I hope its paint is in fairly good shape from the factory. I don't mind some orange peel. I'm going to drive it a lot anyway and it is going to just get scratched, chipped, and faded. But I don't want it to stick out either (like on those Ions).