Orange Peel = Thick Paint?

[imported_truzoom]

Alright this is a question that came up today while I was doing some machine polishing. A topic VERY similar to this came up maybe half a year ago and it quickly turned sour, so I`d hope that we`re all adult enough to not let that happen again.



Does the presence of mild to heavy orange peel on a modern BC/CC finish indicate that the paint is fairly thick? I read up on that excellent Rotary usage PDF posted a week ago and it indicated that a paint thickness of 80-200 microns was safe for compounding. So, is there any possible correlation between mild/heavy orange peel and a paint thickness in the 100-200 micron range?



From what I understand, orange peel occurs due to the solvent used during the painting process. Some solvents evaporate slowly, which allows the paint pigments to evenly level out on a body panel. Other solvents evaporate fast, so the pigments don`t fully settle and smooth and you end up with orange peel. (whether or not orange peel is there on purpose by mfg specs. is IRRELEVANT)



I`m inclined to believe that orange peel`d paint is a fair estimate that the paint is thick enough to be compounded safely. One reason is that many older cars I have worked on seem to lack orange peel, which I believe is due to the natural deterioration of the finish due to the elements (you could also say the EPA regs and water-based solvents factor into this). Another reason is that when I`ve seen a car with a damaged finish where the clearcoat is cracking or the paint is flaking up, there is no orange peel.



Any thoughts on this, Autopia?

[imported_JoshVette]

Most paints are thick enough to be compounded provided you have a person who knows what they`re doing with a rotary....



But the truth is, orange peel does not mean the clear coat is thick at all.



Matter of fact, many paints have been measured with various thicknesses that have more OP and less OP.



Hopefully TOGTW will chime in, he is a chemist and very familier with these things.



Josh

[Setec Astronomy]

Hopefully TOGTW will chime in, he is a chemist and very familier with these things.

I wouldn`t hold my breath on that, since he was banned about 3 years ago. I don`t recall him being a chemist, either.

[the other pc]

I guess you can state definitively that a finish with zero thickness will have zero orange peel.



Other than that, orange peel is not a direct indicator of film thickness. Even if there is some correlation, there are too many other factors involved to use it as a reliable indicator.





PC.