I’ve been requiring intermediate coats of paint be lighter than subsequent coats since I came to the Dark Side. That was in the specs I inherited; it was explained that doing so makes it easy to see if all coats had been applied. I’ve seen this requirement many times, including in guide specs offered by several paint companies.
Recently, I received a copy of a letter sent from a Sherwin-Williams rep to a local painter. The rep said, “Architects sometimes request the intermediate coat to be a color slightly off the actual topcoat. This practice is not followed for several reasons. The most important reason is that a slight color change would show any holidays. These areas would then need to be touched up. If the color is the same color these areas would just blend in. Another reason is that it leads to excess paint materials that then need to be disposed of. Also, colors may be used by mistake during touch up causing a bigger problem.”
This is interesting first because, as noted, some paint manufacturers include the requirement for lighter intermediate coats in their specs, and second because the rep states that the requirement is regularly ignored.
I see the logic on both sides. Do you specify lighter intermediate coats? Why or why not? If you do, are painters ignoring your specs?
I find it interesting that the first reason cited for not following the specifications is that it would “show any holidays.” Isn’t this the intent of the specs. The coats are supposed to be applied without holidays. The specified requirement is so that the “inspector” can see if the spec was followed.
The requirement for lighter tinted intermediate coats has been in my spec since the beginning of time, too – directly from MasterSpec. I have never heard about any pushback, but I don’t know if the provision is being enforced.
The reasons stated in the letter sound suspiciously made up to me – like someone is looking for every possible rationale to argue against this practice without coming up w/ anything convincing.
In SO FL where no one wants to follow the specs, I too have never had anyone question using lighter intermediate coats, I agree with Jeffrey, its ridiculous.
I wonder if the type of substrate and location could “color” your opinion on this? For exterior exposed steel, you might be concerned you get a consistent minimum dmft without holidays because you’re concerned about protecting against corrosion and the elements. For interior gypsum wallboard in an apartment complex that is getting painted every time a tenant moves in or out, do holidays matter as much? Just speculation…
Some of the major paint companies are now promoting “one coat” interior paint finishes for the residential market. If the manufacturer thinks one coat is enough, then of course they aren’t going to care about intermediate coat.
and one of the paint reps with a one-coat system told me to be sure to include the phase “coats to cover” in the specification. In other words, don’t leave holidays whether it takes one, two, or more coats.
For paints that are primarily decorative, I think the criteria should merely be that it covers the substrate completely, and evenly. Sherwin Williams approach in that regard is correct, I think. And, having been a painting contractor in a prior life, I can assure everyone that there is no such this as doing a coat without holidays (although with good technique they will be minimal). However, what would be the measurable criteria for proper coverage? That’s the rub. I generally specifed two coats, insisted on a neat job that looked good at punch list, and left it at that.