What causes orange peel?

[octane]

My wife had the rear bumper on her car replaced following an incident where someone texting and driving preferred hitting cars vs hitting a stray cat...

the new bumper is full of orange peel, the backup sensors (including one that they broke during reinstall) were glued in place, lets just say I'm really not satisfied with the job the place the insurance referred us to ...

so I'm meeting with them tomorrow, and trying to gather some info... before I go postal on them ;-)

Is orange peel caused because they put on coat of paint that were too thick? or just the painter being bad?

thanks

[Setec Astronomy]

Once upon a time, we had a long, argumentative thread on the other forum about why cars today have so much orange peel. In the way-back machine, orange peel was considered a defect, caused by poor practices.

Today the reason that most new cars have it is a bit murkier, but the reason I believe is that there are so many different materials used today on vehicles, particularly the use of galvanized steel, that they don't all have the "Class A" surface that stamped plain steel used to have in the day. So the mfr. wants a certain amount of surface texture so you don't see the difference in substrate texture.

However, if in your case your repainted parts don't have the same amount of orange peel as the rest of the car, that's the shop not matching the rest of the panels. It sure must have been a lot easier back when the painter only had to match the color and perhaps the flake flow without having to also match the degree of orange peel.

[aim4squirrels]

Orange peel hides defects (swirls, scratches, dust nibs, etc) better than a mirrored surface. Much like textured plastic hides scratches better than flat plastic.

Honestly though, I think it's the result of using robots to paint.

The robotic arm stays a fixed distance from the car and sprays. If the panel moves slightly closer or further away, the robot doesn't adjust.

Also, I think they just flat don't use enough paint to adequately cover a panel and let it flow together. They also probably move the arms a bit too fast in order to speed up production, which short changes the vehicle of paint as well.

Basically, it's become (to the manufacturer) "Eh, its good enough to pass it off," and so few buyers actually understand what a real quality paint job looks like up close, they don't balk. They just know the new, shiny car looks better than their old, swirled out, faded trim car that they are replacing.

[brettS4]

I agree with aim4squirrels. I had to have some bodywork done on my A4 about 10 years ago. While the color match was perfect, it was very clear which panels had been resprayed because of the orange peel. Audis don't leave the factory with that, you know. And none of the panels had been replaced. But due to time constraints or lack of skill/concern, the car was 'good to go' according to the body shop.

But thanks to my good buddies Porter, Cable and Menzerna, it was soon fixed.

[4u2nvinmtl]

I agree with aim4squirrels. I had to have some bodywork done on my A4 about 10 years ago. While the color match was perfect, it was very clear which panels had been resprayed because of the orange peel. Audis don't leave the factory with that, you know. And none of the panels had been replaced. But due to time constraints or lack of skill/concern, the car was 'good to go' according to the body shop.

But thanks to my good buddies Porter, Cable and Menzerna, it was soon fixed.

What pads did you use on the PC to remove the OP? Just interested to see if there's another way than Velvet/Denim pads (or wet sanding).

I know it's an old thread but I'm always fighting OP lol...

[RedXray]

Incorrect gun settings (mostly air pressure) and/or incorrect paint viscosity (mixing reducers, catalysts etc.)

[Setec Astronomy]

Honestly though, I think it's the result of using robots to paint.

The robotic arm stays a fixed distance from the car and sprays. If the panel moves slightly closer or further away, the robot doesn't adjust.

Also, I think they just flat don't use enough paint to adequately cover a panel and let it flow together. They also probably move the arms a bit too fast in order to speed up production, which short changes the vehicle of paint as well.

Well, now that this thread is dredged up...wow! Do you really think that a human painter is more consistent than a robot at maintaining distance from the surface?? Particularly by the end of the shift? You realize that it's a digital world, that the car is a digital model, and the robot is programmed precisely to follow the contours of the vehicle? The robot doesn't get tired, the robot doesn't think about what his wife said to him that morning, etc.

As far as there not being enough paint--paint today isn't what paint was years ago, and factory paint isn't the same as bodyshop paint. Today's paint is waterborne, high solids, etc.

To follow up on my reference to another thread in my earlier post, it's really hard to compare what goes on in the paint booth in the factory today vs. 20-30 years ago. The paints have changed, the process has changed, the substrates have changed. I think there are likely differences between North America, Asia, and Europe, and even here in NA perhaps some diffs between US, CAN, and Mexico (as far as VOC's, emissions, etc.)

[2black1s]

There are several causes of orange peel and varying degrees and types of orange peel. Some orange peel is perfectly normal for an as-sprayed finish. For the sake of this discussion let's just focus on what would be considered excessive or abnormal orange peel.

Excessive orange peel is usually the result of:

Improper application, i.e., too light or 'dry' of an application which results in a rough, tight, sandpaper like finish; or too heavy or 'wet' of an application which results in a smoother, less defined, yet muddled or wavy finish.

Improper materials, i.e., a material with too fast or too slow of a drying for the relevant ambient conditions (temp, humidity, air flow, etc.).

For what would be considered 'normal' orange peel, again there are many factors to be considered, i.e., the type of material being sprayed, the substrate material, surface preparation, etc. And then, what is 'normal' is a moving target as paints evolve. Back in the days of acrylic lacquers orange peel was essentially non-existent, or at least very different, relative to today's urethane finishes.

Matching the paint's texture, or in other words, the type and degree of orange peel, can be very challenging in the refinishing industry.

[RedXray]

Back in the days of acrylic lacquers orange peel was essentially non-existent

correct

(cut my teeth shooting lacquer via a Binks #7 in the mid 70's)

1. Lacquers ready to shoot viscosity is water thin (compared to enamels, urethane's, polyurethane's etc.)

2. Lacquer's flow very little and sometimes need a retarder added to even the slowest thinners on hot days.

3. Lacquer is shot 6 to 8+ coats as you'll loose 2+ coats during the buff (all automotive lacquer is compounded for gloss)

[2black1s]

... (cut my teeth shooting lacquer via a Binks #7 in the mid 70's)...

Me too. Although my weapons of choice were a Binks Model 18 or a DeVilbis JGA 502.