Painting is one of the oldest professions and with it come many myths. Possibly the most frequently encountered myth is that application of a coating by brush is a higher quality method than spraying. Following is information you should find helpful when specifying your next paint job, choosing the vendor who will perform the work, and evaluating the quality of the work performed.
Listed below are three of the most frequent reasons people have heard that brushing is a preferred method of application.
1. "You need to brush it in . . ."
'Brushing it in' or 'working it in' are common goals of those who espouse brush applications. However, simple paint chemistry tells us that this is not only undesirable; it is not possible in most repaint applications. Application over existing coatings is meant only to bond to the previous paint job-not soak in or "be brushed in" to the wood. Some primers and transparent or semi-transparent stains (not solid stains or paints) are meant to "soak in" to the substrate. However, these coatings will generally soak in no matter how they are applied as long as the substrate is properly prepared. Back brushing or brushing will not necessarily cause the coating to soak in more. In fact, failures resulting from over-brushing or over-working paints are common byproducts of attempting to make a coating soak in.
2. "Houses are never sprayed so why should you spray my house?"
Contrary to popular belief, houses are sprayed all the time. When houses are not sprayed it is usually for one of the following reasons:
a. Houses are relatively small. The setup time needed for spraying (masking of windows, landscaping, etc; machine setup, cleanup and maintenance) is not always repaid by the amount of time saved by spraying when the job is small.
b. Small contractors paint houses. As a percentage, fewer small contractors own sprayers than large contractors. Larger contractors have the ability to purchase machinery and train applicators.
c. The single-family contracting market is highly fragmented with imperfect information. In this environment, it is difficult to dispel myths such as those regarding spraying.
3. "The paint is peeling and the trim is rotting because it was sprayed."
Peeling is very rarely caused by the paint application and is typically caused by other factors, the two most prevalent causes being moisture transfer and insufficient preparation. In some cases, peeling can be a result of a poor quality substrate (pine trim or smooth side "mill glaze" clapboards). However, in both instances, moisture transfer and insufficient preparation ultimately cause the peeling of the paint. The method of coating application will have very little if anything to do with the peeling. Application methods do not create or correct moisture problems, original coating adhesion problems, low-quality building materials etc.
When deciding to paint your home, try to specify the application method based upon facts. The statements listed above are not so much reasons for brushing, but rather attempted indictments of spraying. They are neither factually based nor backed up with data.
Of course, a poor spray job is worse than a good brush job just as a poor brush job is worse than a good spray job. Often, perception of spraying is based upon an experience with someone that was not properly educated or experienced in correct spray technique. The results of improper spray technique are more readily apparent than poor brush technique. Uneven application and insufficient coverage, typical brush application deficiencies, are much more difficult to pinpoint.
Proper application of coatings-sprayer or brush-will provide the desired result: an attractive, durable finish. A process that delivers a higher quality job when performed properly and costs less deserves your attention and consideration.