Orange peel? Yuk!
06-05-2005, 10:14 PM
#16
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Originally Posted by Porschephile 924
It's not Orange peel, it's a "Monet"
btw, wetsanding will do wonders (if you know what you're doing). . . its a good way to ruin a paintjob if you don't.
Take it to a good bodyshop and see what they'd recomend.
06-06-2005, 10:49 AM
#17
RL Community Team
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What Ferkel said is spot on. Orange peel to some extent is visible on nearly every OEM finish. The lighting conditions and colour have a lot to do with how visible it is. I find myself looking very critically at car paint these days and find that even beautiful, glossy finishes that look perfect at first, will have some degree of orange peel. But again, depending of the colour, gloss and what type of light you are under, it can be hard to see. Cut and buff can eliminate this (assuming enough clear is present) but this is not normally done in production of most cars, even Porsches. It all depends on what you look for. There are other factors to a quality paint job and when I look at any new Porsche, I find the paint overall is very good and the very subtle orange peel is not a turn-off at all. Now yesterday I saw an Aston Martin Vantage and THAT finish was cut and buffed and looked incredible (not sure if that is factory or not... Astons are very rare in these parts).
If you are looking at an '80's non-metallic Porsche (original paint) than colour sanding may not be a good idea. The paint is most likely Glasurit single stage urethane (known as -22 line these days). I've heard from industry professionals that these paints dry with a sort of film that has a high degree of UV resistance. Although normal polishing is usually not enough to remove this film, a colour sand may. How critical this is I don't know though.
If you are looking at an '80's non-metallic Porsche (original paint) than colour sanding may not be a good idea. The paint is most likely Glasurit single stage urethane (known as -22 line these days). I've heard from industry professionals that these paints dry with a sort of film that has a high degree of UV resistance. Although normal polishing is usually not enough to remove this film, a colour sand may. How critical this is I don't know though.
06-06-2005, 03:14 PM
#18
Race Director
Yup, exactly what Ferkel said. Along with some of the other tidbits as well. One factor is the equipment used and prep. Orange-peel is caused by the droplets of paint impacting the surface and causing a splash or a crater. The bigger the drops, the rougher the orange-peel. With modern low-pressure/high-volume spray equipment that reduces paint-waste and gives quicker spray rates, the droplets are much bigger than older equipment. Bigger drops leads to more orange-peel. Once the drops lands and creates a crater, the surface has to flow and even out.
The other factor is the regulations and VOC content of modern paints. My favorite when worked in a body-shop was Dupont Imron because flowed for about 20-30 minutes before curing. But low VOC regulations and its cyanide content outlawed it. It was also tremendously popular in the custom motorcycle and bicycle markets. Modern low VOC paints have more solids, less thinners, so they don't flow as well. Combine that with shop-production cycles that favor quick-drying paints and you'll more likely see more orange peel than you would a couple decades ago.
For the really nice paint jobs without exhorbitant costs, I'd use two stages and let the 1st layer dry suffciently to color-sand. After that, the clear goes on multiple stages as well. The final wet clear layer goes on with a finishing gun to get as fine of a mist as possible (small droplets). Since the volume delivered by a finishing gun is only 1/10th of what you typically get from a bigger gun, it takes a long time to apply a wet final layer ths way and it's not used very often.
This multiple-stage paint with color-sanding and final layer with finishing gun is definitely not something you'd get in a car manufacturer's plant. It takes too long to wait for a paint that takes 20-30 minutes to flow, 4-5 hours to harden to where you can color-sand it. The whole paint-job, even with automated equipment would take at least 14-16 hours, so you're not going to get it from most factory paint jobs. The best gloss I've seen have been at the classic car shows with the antique Rolls and Ferraris. These are typically very hard lacquer paints compared to todays enamels and poly-urethanes. Lacquers dry very fast, so you'll end up with a lot of orange-peel, but they allow you to lay down a thick layer without running, then its color-sanded meticulously to remove all the tops of the bumps, then polished to a mirror shine. Can take months to do...
Some kid in San Diego did something similar to his 944 with spray cans !!! Turned out very, very impressively!
The other factor is the regulations and VOC content of modern paints. My favorite when worked in a body-shop was Dupont Imron because flowed for about 20-30 minutes before curing. But low VOC regulations and its cyanide content outlawed it. It was also tremendously popular in the custom motorcycle and bicycle markets. Modern low VOC paints have more solids, less thinners, so they don't flow as well. Combine that with shop-production cycles that favor quick-drying paints and you'll more likely see more orange peel than you would a couple decades ago.
For the really nice paint jobs without exhorbitant costs, I'd use two stages and let the 1st layer dry suffciently to color-sand. After that, the clear goes on multiple stages as well. The final wet clear layer goes on with a finishing gun to get as fine of a mist as possible (small droplets). Since the volume delivered by a finishing gun is only 1/10th of what you typically get from a bigger gun, it takes a long time to apply a wet final layer ths way and it's not used very often.
This multiple-stage paint with color-sanding and final layer with finishing gun is definitely not something you'd get in a car manufacturer's plant. It takes too long to wait for a paint that takes 20-30 minutes to flow, 4-5 hours to harden to where you can color-sand it. The whole paint-job, even with automated equipment would take at least 14-16 hours, so you're not going to get it from most factory paint jobs. The best gloss I've seen have been at the classic car shows with the antique Rolls and Ferraris. These are typically very hard lacquer paints compared to todays enamels and poly-urethanes. Lacquers dry very fast, so you'll end up with a lot of orange-peel, but they allow you to lay down a thick layer without running, then its color-sanded meticulously to remove all the tops of the bumps, then polished to a mirror shine. Can take months to do...
Some kid in San Diego did something similar to his 944 with spray cans !!! Turned out very, very impressively!
