Now that waterborne finishes have officially assumed control of the supply chain in our industry, I want to dedicate this month’s column to sharing the intel on best strategiesfor using waterbornes to create the finer finishes that generally required oils in the past.
There seems to be confusion among painters, especially on the Internet, about how paints work these days. Some experts overcomplicate it, others oversimplify it. The bottom line is that while the products are changing frequently, painting is still a subjective discipline.
Whenever I read articles written by home and garden experts talking about how you should “never” do this or “always” do that with paints, it is a red flag. There is very little about the painting process that can be all that prescriptive.
There are too many variables to objectify the process in that extreme or absolute of a manner.
Work habits can be more regimented, and that is a good thing for daily efficiency, organization and productivity. But the steps in your process of actually preparing surfaces and painting them—especially in the new world of waterbornes—need to have some flex to them.
THINGS TO KNOW
Waterbornes are pretty much the opposite in behavior from traditional oils. Oils stayed wet for a very long time. You could brush and brush and brush with little risk of flash. During the drying stage, oil would stay wet and level itself out, eliminating brush marks and creating a smooth-laid finish. While slow drying, the cure times for oils were generally short.
We used to use the term “kick” during the drying process with oils, as in, “when this kicks, it is going to be glass.” I have trained and advised enough painters in the past few years to understand the confusion and counterintuitive nature of relearning how to paint with waterbornes. The psychology of changing from oil to waterbornes comes with stages of resistance, denial, frustration, anger and finally acceptance.
It is possible to accelerate these stages for yourself and the employees that you probably have to train to work with the new era of paint products. The basic premise is that if you try to paint with waterbornes the way you always painted with oil enamels, the results will not be desirable. That is a great reason to consider alternate strategies.
CHANGE THE WAY YOU BRUSH
This is so easy to say, and so not easy to do … at least initially. To summarize in the simplest way: to get good brushed results with waterbornes, it is best to lay it on heavily, resisting the temptation to overbrush. Because waterbornes tack up much more quickly than oils, if you apply more, it will stay wet longer and therefore level out better. That is the concept. That is how you control the paint instead of letting the paint control you.
I also frequently recommend that painters control the microclimate they are working in. In my experience, waterbornes seem happiest in a slow “lay down” at no more than 60 degrees. So there is a big difference between overbrushing a thin coat at 70 degrees and liberally laying down a heavier coat in cooler temps—huge performance differences result just by playing with those two variables.
At the back end of the process or during the drying stage—no matter how heavily you apply waterbornes—they will generally tack up much quicker than oils ever did. Personally, I like this trait because it minimizes contamination risks during the dry stage.
However, while waterbornes tack and dry fairly quickly, they are usually slowcuring products. In other words, they can be dry enough to handle, and even lightly sand and recoat, but they usually take a significant amount of time to fully cure to the point that they lose that “sticky” feeling.
Especially cases involving, for instance, cabinet shelves or doors that you might want to stack on top of each other. Once the finish has tacked, I find it best to turn up the heat and move air over the surface with a low-speed fan to induce curing.
CHANGE THE WAY YOU SPRAY
Spraying with waterbornes is also a different experience than with oils. Historically, oils often called for a “tack coat” technique in building finishes, which was terribly time-consuming, given dry times.
You could “wet on wet” to the point where you knew it would hang on, but then you were pretty much shut down for at least a day before continuing. Waterbornes, on the other hand, can be sprayed more liberally because they are built with more “tooth” for adhesion – to hang onto the primer underneath and to hang onto itself – with lower risk of runs, sags or curtains. By taking advantage of the ability to spray thicker coats in each session, finishers can manipulate the leveling characteristics of waterbornes to their advantage.
One cabinet finisher gave me the following feedback after spraying waterborne on paint-grade cabinets for the first time with HVLP in a shop environment: “I was surprised … a little scared, actually. The satin sheen seemed really flat to me as it first tacked up, but as it dried, the orange peel laid down and melded, almost like it needed to fully flash off, and then the sheen could rise to the top. It took a while for it to fully dry, and I was nervous the whole time, but it came out great …” This sums up very well the fear and discomfort that comes with completely changing your technology and application style. The first time is the hardest, but usually when people experience favorable results, they are able to make wholesale changes in habits and strategies.
THE GOOD NEWS
Once you retrain yourself, waterborne processes and habits transfer very well across the different types of formulations. Primers, paints and clear finishes, both interior and exterior, share many of the same working properties, so your process can be dialed for repetition, efficiency and quality results, as long as you keep an eye on situational variables such as your microclimate as you go. APC
About the Author
Scott Burt is president of Topcoat Finishes Inc., in Jericho, Vt. He enjoys communicating with contractors and manufacturers at www.topcoatreview.com.