Direct to Substrate Trend -- One Paint That Does the Job of Two

In last month’s newsletter we talked about “why paints fail”. And consistent with PQI’s recommendations we discussed steps to minimize paint failures, including the role of primers. This month we introduce you to a new trend - Direct to Substrate (DTS) applications. We will show that the perfect finish, which resulted from a select primer plus 2-coats of a quality topcoat, can now be replaced by 2-coats of a DTS. The value proposition for professional painters and consumers alike is straightforward – one less coat (labor plus material) needs to be applied!

In last month’s recommendations on using primers, we briefly discussed the fact that today’s primers are optimized to deliver superior performance on selective surfaces. Consumers and contractors alike are fairly familiar with some of the primers on the market – e.g. drywall primers (for painting over fresh drywall); stain blocking primers (for blocking tannin stains in wood); and even metal primers (for inhibiting corrosion in applications over metal).

Primers are designed to serve many purposes. They seal the substrate to be painted allowing for more efficient and uniform coverage with a topcoat. Primers also serve as a tie layer – providing optimum adhesion to the substrate and providing a compatible surface for the topcoat to stick to. As new substrates and building practices evolve, we see primers evolving to enable a desired effect – for example, helping to accentuate the smoothness or roughness of a surface. And as we mentioned above, primers are also optimized to block stains (particularly tannins in wood).

Not all primers are created equally: We illustrate this in the two figures below. In Figure 1, we show durability performance for two coats on yellow pine. The panel shows five segments each representing 2 coats. The first two segments are primers with no top coat. The next two panels show the application of the primers with quality acrylic top coat. The paint on the far right is a crack (fail) control. We also show the impact of binder chemistry – alkyds not only tend to yellow but continue to crosslink, becoming rigid and crack as the film ages. Figure 1 also shows that traditional primers are not optimized for long term durability, hence, little surprise that a primer and topcoat outperforms 2 coats of primer.

Figure 1: Primers – utility and type on yellow pine.

Best Option – High Quality Primer: A more impressionable real world application is captured in the shutter images. Performance over a 3-month weathered vinyl shutter is shown -- this is a typical repaint opportunity. The image on the left shows 2 coats of topcoat without primer while that on the right has one coat of primer plus one topcoat. The primerless finish is inferior and shows severe blistering. PQI and most manufacturers recommend a primer plus 2 coats of topcoat to ensure the best coverage and adhesion and to maximize durability and appearance.

2-Coats Topcoat (No Primer)	Primer + 1-Coat Topcoat
Click here to see how primers can prevent occasional nail head rust!

Direct to Substrate Trend: What if a technology can be developed that brings the best properties of the topcoat (e.g. durability and appearance) with that of the primer (e.g. adhesion and stain blocking)? This is in fact the case today. More manufacturers are introducing these direct to substrate (DTS) paints that deliver excellent performance from a single can. That is, as opposed to using a primer followed by 2 coats of a topcoat, the same performance can now be delivered with 2 coats of a DTS paint. We highlight two examples below that clearly demonstrate that both topcoat (durability) characteristics and primer (stain blocking) characteristics can now be built into the same binder. The figures below show that two coats of a DTS outperform 2 coats of top quality acrylic paint or a primer plus topcoat for stain blocking. And at the same time, the DTS has equivalent exterior durability. We anticipate that the use of this DTS will be a growing trend in the market and would bring real value to contractors as they can now deliver the perfect finish with one fewer coat of paint.