What causes "orange peel" and how can it be corrected?
- Thread starter KatyM45S
- Start date
imported_Luster
New member
No, you didn't cause it. Orange peel occurs when the car is being painted. Prior to the final polishing of the paint, it should be wet-sanded to remove imperfections, such as orange peel, fish-eyeing, etc.
But today's car manufacturers don't do that anymore. Cost's too much. (evidently)
Paint, polish, ship....and if it has orange peel, so be it.
So, in answer to your second question, yes, the only way to remove orange peel is wet-sanding.
Old Pirate
AMG Classic Car Detailing
Couldn't said it any better...
My understanding is that the newer VOC environmental laws have required the paint process to change and newer paint compounds have changed resulting in more orange peel. I'll yield, however, to the post hopefully forthcoming from TOGWT!
If it's any consolation Katy it's on every car.
If it's any consolation Katy it's on every car.
Todd@RUPES
Just a regular guy
Even Porsche's have considerable orange peel, as do Lamborghini's, Ferrari's, and just about any new car made today. Bentleys are pretty flat, and the hand built Bentley Arnage that I detailed last year was probably the flattest paint I have seen on an OEM car.
David Fermani had a good post about how orange peel increases the surface area of the paint, which should lend to slightly longer life. Also, a lot of body panels are not straight, but wavy. A flat paint job would show the waves in the body panels.
Corvettes, and in particularly Z06/ZR1's with their carbon fiber qp's, have a huge amount of orange peel in the paint.
What causes orange peel?
From my very basic understanding, paint is a liquid with solvents, when it is sprayed. The liquid is atomized, or separated into a very fine mist, during application. The finer the atomization (in combinations with the solvents used) the more even the coat that lays down and the quicker and more even the evaporation of the solvent, allowing paint in dry evenly. Painting a car is both an art and a science. The way the paint is mixed is very important, as the proper amount of solvent and spray must be calculated based on environmental factors which effect drying, as well as the spray flow and pattern.
Even when all the factors are perfect, you are still dealing with applying a liquid as evenly as possible on a surface. In the real world, as the paint dries, certain areas harden quicker. In these areas the paint will flow away, creating a texture in the paint. Keep in mind this is very basic.
Most automotive paints are now water based as it is better for environment.
To my knowledge, GM was the first to 'go green' in the mid 1980's. The problem is that the paint takes longer to dry (and thus dry evenly) so the texture effect can be more pronounced. At the assembly line, time is money (or at least to be fore the economic meltdown) and efficiency is everything. I don't have near enough experience to know if it is even possible to lay water based paints completely flat, but the rate at which factories must do work at, is likely not beneficial to getting the best possible finishes.
Let's say that if GM was to slow the factory speed to the point that it now costs more money to create a vehicle. When amatorized into the cost of each individual product, lets say the price goes up $700. (I have no idea). In a tough competitive market, the $700 price increase would likely not represent a good value to people (although it would to us!). Keep in mind that it would be a nice to have it offered as a $700 dollar option, but then you would have to amatorize the cost of having another assembly line built, just to run at a different rate, and it then it would be a scary price increase.
How to remove orange peel?
Orange peel likely starts with the first couple color coats and becomes worse with additional coats. All it takes is one coat to have orange peel to have the problem. By sanding the top layer flat you can create an orange peel free finish, although it would ideal to have the base coat (color coat) as flat as possible to avoid over thinning the clear coat in areas where the orange peel is high.
Keep in mind that completely removing orange peel on modern, baked, factory paints is for the most part impossible. It is fairly easy to remove the high spots and reduce the orange peel, but as the paint gets flatter, the paper (even with a backing pad) begins to travel over the now subtle differences in surface height. You begin to take down all of the paint vs. just the high spots. On fresh paint, it tends to be easier to flatten the paint, if that makes sense.
On a modern factory finish, it would be best to start with very aggressive paper with a stiff backing plate to cut the paint and create a completely new, flat surface. Then, by using finer and finer papers, the new surface would be refined. It is better to cut through the orange peel then try to remove trace amounts at a time. The problem, of course, is while this would create flat paint, it would would remove large amounts of the already thin paint. Again a reduction in orange peel is certainly possible, but a complete removal is often impossible and at best reduces precious material to the point of compromising the paint.
Keep in mind the orange peel you see on most factory paints isn't that bad. If you have seen a cheap paint job, like a Maaco special, then you likely noticed areas that have little pebbley orange peel that completely reduce gloss.
I'll forward this to Kevin Brown, as he has a LOT more experience in sanding paints then I do, and could probably add way more to the discussion.
David Fermani had a good post about how orange peel increases the surface area of the paint, which should lend to slightly longer life. Also, a lot of body panels are not straight, but wavy. A flat paint job would show the waves in the body panels.
Corvettes, and in particularly Z06/ZR1's with their carbon fiber qp's, have a huge amount of orange peel in the paint.
What causes orange peel?
From my very basic understanding, paint is a liquid with solvents, when it is sprayed. The liquid is atomized, or separated into a very fine mist, during application. The finer the atomization (in combinations with the solvents used) the more even the coat that lays down and the quicker and more even the evaporation of the solvent, allowing paint in dry evenly. Painting a car is both an art and a science. The way the paint is mixed is very important, as the proper amount of solvent and spray must be calculated based on environmental factors which effect drying, as well as the spray flow and pattern.
Even when all the factors are perfect, you are still dealing with applying a liquid as evenly as possible on a surface. In the real world, as the paint dries, certain areas harden quicker. In these areas the paint will flow away, creating a texture in the paint. Keep in mind this is very basic.
Most automotive paints are now water based as it is better for environment.
To my knowledge, GM was the first to 'go green' in the mid 1980's. The problem is that the paint takes longer to dry (and thus dry evenly) so the texture effect can be more pronounced. At the assembly line, time is money (or at least to be fore the economic meltdown) and efficiency is everything. I don't have near enough experience to know if it is even possible to lay water based paints completely flat, but the rate at which factories must do work at, is likely not beneficial to getting the best possible finishes.
Let's say that if GM was to slow the factory speed to the point that it now costs more money to create a vehicle. When amatorized into the cost of each individual product, lets say the price goes up $700. (I have no idea). In a tough competitive market, the $700 price increase would likely not represent a good value to people (although it would to us!). Keep in mind that it would be a nice to have it offered as a $700 dollar option, but then you would have to amatorize the cost of having another assembly line built, just to run at a different rate, and it then it would be a scary price increase.
How to remove orange peel?
Orange peel likely starts with the first couple color coats and becomes worse with additional coats. All it takes is one coat to have orange peel to have the problem. By sanding the top layer flat you can create an orange peel free finish, although it would ideal to have the base coat (color coat) as flat as possible to avoid over thinning the clear coat in areas where the orange peel is high.
Keep in mind that completely removing orange peel on modern, baked, factory paints is for the most part impossible. It is fairly easy to remove the high spots and reduce the orange peel, but as the paint gets flatter, the paper (even with a backing pad) begins to travel over the now subtle differences in surface height. You begin to take down all of the paint vs. just the high spots. On fresh paint, it tends to be easier to flatten the paint, if that makes sense.
On a modern factory finish, it would be best to start with very aggressive paper with a stiff backing plate to cut the paint and create a completely new, flat surface. Then, by using finer and finer papers, the new surface would be refined. It is better to cut through the orange peel then try to remove trace amounts at a time. The problem, of course, is while this would create flat paint, it would would remove large amounts of the already thin paint. Again a reduction in orange peel is certainly possible, but a complete removal is often impossible and at best reduces precious material to the point of compromising the paint.
Keep in mind the orange peel you see on most factory paints isn't that bad. If you have seen a cheap paint job, like a Maaco special, then you likely noticed areas that have little pebbley orange peel that completely reduce gloss.
I'll forward this to Kevin Brown, as he has a LOT more experience in sanding paints then I do, and could probably add way more to the discussion.
Once again, you guys are freakin awesome! As I told Todd in a private message, I have somewhat resigned myself to the fact that this car will most likely never reach perfection in my eyes. Between the hard clear coat and the (minor) orange peel, I'll always have something to complain about! I should be wrapping up my three-evening work on my car tonight and will post pictures. Though there will be no sunshots, as my PC and various pads/polishes did very little with the swirling I have. It kills me to think that after playing with different processes/techniques for about 13 years, I still have never found "the one" for me.
I guess I'll have to breakdown and buy some new products!Boo Hoo
I guess I'll have to breakdown and buy some new products!Boo Hoo
PorscheGuy997
New member
Wet sanding a car is not an easy thing to do correctly. It takes a lot of time and patience.
When starting out, it's nice to know the history of the paint. Is it factory or is it resprayed? In each instance, it is best to have a thickness gauge to measure the film build.
As Todd mentioned, the backing pads are very important. A very stiff pad will level paint flat, while a more flexible one can be used to remove minor defects or to complete the final sanding before polishing. When DA sanding, the interface pad becomes even more relevant. If you have a very thick pad, it will absorb some of the motion of the DA and reduce the cut. Or, you can just attach the abrasive to the paper and level flat areas. For final sanding, I like to use a medium thickness interface pad and 4000 grit abrasives because the amount of material removed is minimal.
I've sanded out a number of hoods. One sticks out from all the rest. It was a black Chevy hood that had been repainted in single stage black. The paint had some serious orange peel. I started with some 1000 grit disks and worked up to 4000 grit. Afterwards, the surface was absolutely flat. When sanding out very bad orange peel, it is necessary to go pretty aggressive. Just be aware of the film build.
DA sanding will not product a finish that is as flat as hand sanding. However, it is much, much easier and will really cut down the time to complete.
When starting out, it's nice to know the history of the paint. Is it factory or is it resprayed? In each instance, it is best to have a thickness gauge to measure the film build.
As Todd mentioned, the backing pads are very important. A very stiff pad will level paint flat, while a more flexible one can be used to remove minor defects or to complete the final sanding before polishing. When DA sanding, the interface pad becomes even more relevant. If you have a very thick pad, it will absorb some of the motion of the DA and reduce the cut. Or, you can just attach the abrasive to the paper and level flat areas. For final sanding, I like to use a medium thickness interface pad and 4000 grit abrasives because the amount of material removed is minimal.
I've sanded out a number of hoods. One sticks out from all the rest. It was a black Chevy hood that had been repainted in single stage black. The paint had some serious orange peel. I started with some 1000 grit disks and worked up to 4000 grit. Afterwards, the surface was absolutely flat. When sanding out very bad orange peel, it is necessary to go pretty aggressive. Just be aware of the film build.
DA sanding will not product a finish that is as flat as hand sanding. However, it is much, much easier and will really cut down the time to complete.
imported_Luster
New member
Haha
.... yeah, if you're going to practice wetsanding, go get an old fender!!!:cornut: