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Discussion Starter · #1 ·
Is it reasonable for a painter to say he is going to spray on two exterior coats by going up and down with a gun and then back and forth? Does it count as two coats if the second one goes on over a wet first one? It looks like he got a lot of paint on the wall. I can't find any thin spots. He used a hvlp system with latex.
 

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Go Cardinals!!!
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Generally, 2 coats means with the proper dry time between coats as per manufactures specs. I know this was discussed on CT awhile back and wet on wet is not 2 coats.:no:
 

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speed comes with quality
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Actually you can,see a certain paint has certain amount of coat specs to reach a certain amount of millage.If you've ever worked a state job or something high priority like the inside of ships,you have a certain millage you have to meet.Unlike on say a regular industrial job the spray men are highly trained and well paid because the millage has to be dead on per coat.Not enough and your in trouble and too much and the same.So yes you can spray on the same thickness with one coat as you can rollng 2 coats.As long as you don't back roll. but I agree technically it's not really 2 coats.
 

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Discussion Starter · #6 ·
I have done a lot of painting and at one time painted commercially, but I am out of the business. I would have a hard time complaining about this job. I have had two rolled coats that did not look as thick. And I could not find any drips, sags or overspray. It looks like this kid knew how to handle a spray gun. On the other hand, I feel cheated, because everything I know says two thin coats are better than one heavy coat.
 

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speed comes with quality
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I have done a lot of painting and at one time painted commercially, but I am out of the business. I would have a hard time complaining about this job. I have had two rolled coats that did not look as thick. And I could not find any drips, sags or overspray. It looks like this kid knew how to handle a spray gun. On the other hand, I feel cheated, because everything I know says two thin coats are better than one heavy coat.
Never said anything about anybody being better or not as good, it just sounded different then what I ment.I was simply trying to distinguish the difference when you have to hit the millage.
 

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Epoxy Dude
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Hmmm... Who decides what one coat is?

If it's paint I made... I do. Likewise, manufacturers (chemists) decide what one coat is when they decide how to apply the product. Right?

I don't know of one chemist that would consider this two coats. Anyone who says it is one coat doesn't know how to count or they don't understand how paint works. In addition, they don't understand how or why we (manufacturers) write instructions and decide how products should be applied.

First, if the paint to be applied is 100% solids then it is safe to overlap wet on wet as long as the coating has the proper sag resistance. However, most of the paints you guys apply are between 25-50% solids. So, you have to think about why we say to apply the coating in X number of coats to acheive a certain mil thinkness. First, when you have solvent or water in a coat, it must come out of the film before the coating dries on the surface and traps the solvent/water into the film. If this does not happen it will be a very weak coating and it's properties will suffer such as adhesion, yellowing, hardness, pinholing/loss of gloss, and just about everything else. One good way to make sure you trap the water/solvent in the coating and do a bad job is to apply the coating so thick that the solvent can't reach the surface to escape before the surface dries and traps it in. In other words, chemists do tests to see what the maximum thickness can be (at different temperature and humidity variables) to allow an acceptable percentage of the solvent/water to escape.

There are also good reasons to wait the suggested amount of time before recoat which we have discussed in another thread. I'm not going to rehash that her right now...

So, basically I'm saying that definitively... "That is ONE coat"! In addition, I'm saying that unless the calculations were done (based on the exact temperature, humidity, and substrate temperate at the time of application to determine if the solvent/water would have enough time to exit the film before skinning), and the paint was applied beyond the manufacturers recommendations, that the applicator is taking a huge risk. It's not that those types of paints cannot be applied beyond the recommendations, but that it can only be done in certain atmospheric conditions.

My carpal tunnel is acting up... gonna rest it now...
 

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Is it reasonable for a painter to say he is going to spray on two exterior coats by going up and down with a gun and then back and forth? Does it count as two coats if the second one goes on over a wet first one? It looks like he got a lot of paint on the wall. I can't find any thin spots. He used a hvlp system with latex.
No, it's still one coat. For paint, you must wait anywhere from 2 to 4 hours minimum (depending on product) before you "recoat" it. That's two coats, waiting for it to dry, then re-applying. That's the correct way of applying paint and what the companies want you to do. STAINS, are different. Most companies want one coat for oil stains. But you also want to apply as much material as the wood will soak up. So, for stains (exterior) I always tell people if it needs a second (coat) or more material, apply the stain "wet on wet" It's essentally one coat, just like the company recommends, but you're getting enough material on, and the wood is still taking the stain. It's SO WRONG to apply oil stain wet on dry, i can't stress this enough. Once stain is dry, it create a formidable skin, and eliminates penetration. Does anybody here also run into painters and argue about the whole wet on wet vs wet on dry oil stain application?
 
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