Good Prep = Good Adhesion

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Last year, at top coatreview.com, we spent a considerable amount of time testing, evaluating and assessing several latex primers. As a category, this group has grown in leaps and bounds during the unpredictable and at times confusing modern era of product reformulations. Our findings during testing have been that if they are used in conjunction with their new-generation paint counterparts, the results can be bullet-proof.To summarize, here are the standards by which we measure primers – and paints, for that matter – during testing for review online or in print publications. You will notice that every criterion is fundamentally a question of “how.”We measure products based on the following questions:

  • How does it brush?
  • How does it spray?
  • How does it roll?
  • How does it smell?
  • How does it dry?
  • How does it sand?
  • How does it hide?
  • How does it adhere to multiple substrates?
  • How do a variety of paints adhere to it?

There are other more advanced measures, but these are the basics that apply to just about all primers and paints.While each of these questions is certainly worthy of its own article, we find that the two most important questions are also the two most misunderstood – or at least misdiagnosed – when primer and paint performance are discussed. I am talking about the final two questions on adhesion.ADHESIONIn general terms, adhesion refers to how each layer of a finish system bonds to what it’s applied to. And, more importantly, how does it hold on. This characteristic is usually challenged both in real life and in manufacturer-simulated settings by what it would take to remove it. Usually layers are removed or compromised by being scuffed, scraped or pulled off.Adhesion is the most misunderstood paint characteristic. We all have taken phone calls from customers who painted their kitchen cabinets, or even hired painters to do it, and the paint is prematurely flaking and peeling. The obvious conclusion is paint failure. Especially when the original paint job was oil, and it was painted over with latex. It is entirely too easy to say that the paint didn’t work well.This is a simple matter of cause and effect. People observe the effect, because it is immediately detectable by the senses: The paint is coming off in flakes or even sheets; therefore, the paint failed. It is the job of the professional painting contractor to diagnose cause in order to determine remedial action. By this I don’t mean asking what kind of paint it was and if it wasn’t your preferred brand, blaming it on that. Like a forensic detective at a crime scene, you have to figure out what happened.More often than not, everything that was done – and, more important, NOT done – prior to the application of paint is the culprit in the failure. Paints don’t fail nearly as often as painters do in their processes.I’ve seen some misguided info on the Internet about adhesion. It is often suggested that a primer (or paint or primer and paint in one) either “has good adhesion” or doesn’t. This reasoning is flawed, and at times a cop-out in a skewed assessment. Adhesion, like many other product characteristics, can be entirely manipulated or facilitated.EDUCATE YOUR CUSTOMERSWell, I entirely understand but don’t condone the reality that in the highly competitive world of paint contracting, when pencils get sharpened, surface prep is the first part of the process to suffer. Some contractors eliminate steps, and others invest in better products and gear to expedite prep efficiency. If anything, it is best to err on the side of overkill, or adding a step to guarantee success, rather than skipping steps to either lower your price or boost your profit.When investigating apparent paint failures, look for evidence of skipped steps. When paint peels, it is very easy to get to the substrate and analyze it. If it wasn’t scuffed or sanded, if an intermediate bond coat was not used, it’s a pretty easy investigation.The customer who has just learned the hard way – suffering a miserable and inconvenient paint failure violation at the hands of a sloppy contractor – really wants to talk only about how to make sure that nothing like this ever happens again in their house.HOW TO FACILITATE ADHESIONAdhesion is not a guaranteed inherent quality in any primer or paint product, any more than normal blood pressure is a sure expectation during a physical exam. Blood pressure in a healthy range is a function of lifestyle and genetics. Adhesion is a function of prep habits and formulation quality.The steps to ensure adhesion are ridiculously simple. It blows my mind a bit that painters think they could be worth skipping. But in an age where painters can be convinced to skip primer altogether, I am increasingly less likely to be surprised.This is by no means a prescription, but some steps that facilitate adhesion include:

  • Cleaning all surfaces
  • Scuff sanding
  • Tack wiping
  • Intermediate coat of primer
  • Scuff sand
  • Finish coat
  • Scuff sand
  • Finish coat

Depending on the existing coatings, the condition of your substrates, your application methods and product choices, this can vary, but I am sharing this as pretty much a worst case or most comprehensive sequence that you might consider. Your situation, which is based on your assessment, may include some combination of any or all of these steps.It’s easy to blame product. It’s easy to tweak process in ways that compromise adhesion. The great irony of paint contracting is that it is easy to sell bad work. It’s fast, convenient and cheap – all attributes that customers look for. But you generally get to sell bad work to a customer only once. And most good contractors know that it’s just about impossible to build a successful painting business without repeat customers. Be the professional who does it right. It is at once challenging and bittersweet, but selling good, honest work might actually be considered “cutting edge” these days. APCScott Burt is the president of Topcoat Finishes, Inc., in Jericho, Vt. He enjoys communicating with contractors and manufacturers at topcoatreview.com

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