With the move to Waterborne technology many manufacturers are touting faster production times due to many factors. If you read their literature or watch their training videos it seems that you could almost paint a whole vehicle in 20% of the time it takes to paint with solvent based paints but are Waterborne Paints really increasing production by that much?
Well the answer to this has a lot to do with the manufacturer, the individual product line the color you are painting and whether you pant on a Monday or a Friday. Obviously the Friday Vehicle is gonna get done before lunch so you can start the weekend early.
Most manufacturers will only state that their base Black used as a factory pack or tint is strong enough to cover in just two passes but it seems that DuPont is going one better and stating that all of their colors are recommended to be painted with just one and a half coats of basecoat paint.
The Cromax line of DuPont Paints .. well DuPont for the next few months… is suggested to be sprayed with one full coat of paint at a distance of 8 inches from the surface with a 1.5 or smaller tip and a second half coat that is sprayed at 12 inches from the surface to provide uniform metallic layout.
The color of paint that I have seen painted included a dark red metallic, silver and yellow. The Red seemed to do best with no problems on coverage the yellow seemed a little thin and relied a lot on a matching primer. If the primer was an opposite say a black or a red under the yellow I wonder if it would have had as good results as a light gray.
As for other manufacturers it seems that most painters are not seeing full coverage in 1.5 or 2 or even 3 full wet coats.
Matrix suggests 2 full coats on only their base black. I have seen PPG waterborne paints that have taken 5 coats of base to cover fully however 4 coats probably would have been enough.
I think there are many factors on whether you really have a shorter paint time in the booth.
When I was watching some Cromax be painted the overlap is at least 75% and that means one coat is really one and a half standard 50% overlap coats. The product is suppose to be wet on wet coats due to its formulation and must be applied with the larger overlap to keep it wet while you paint.
Final Note
Waterborne paints do seem to cover faster then standard solvent based paints but not every formulation is the same.
Another factor is drying / flashing between coats which is pretty much eliminated between coats but when the clear is applied the product must be dried.
I have shot solvent clear over base with 30 minute in between flash time and I have shot solvent clear over solvent base with almost continual painting based on the day.
I am not sure with all the equipment and change over of your gun to paint waterborne that it is really so much faster then solvent in every situation but I do like the idea that it is probably a healthier condition for painters.
Even if it took slightly longer if there was a large reduction in carcinogenic chemicals it would be worth the investment.. but for now we will still see.