A coating can be defined as a layer of something spread over part or all of a substrate for decoration or protection. Coatings are often confused with or referred to as “paints”. In the broad sense of the word both terms are more or less synonymous but in our industry we try to differentiate the terms this way. Coatings are generally “paints” that offer more than an aesthetic purpose or result. Coatings are usually applied thicker than most paints as well as offering a performance advantage in a few different areas depending on the coating discussed. For example, most coatings will offer one or more of the following advantages over typical paints: abrasion resistance, chemical resistance, water resistance, corrosion resistance, graffiti control, elasticity and longevity among many other characteristics.
Prior to choosing a coating it is important to understand you or your customer’s criteria in order to make the correct choice. Understanding the anticipated usage of the substrate is critical to making that correct choice.
Typically wall coatings are used for both performance and decorative purposes although the performance characteristics are often at a lower level than floor coatings due to the lack of traffic. Exterior wall coatings do have to deal with UV radiation, which degrades any coating to a certain degree but other than water they generally don’t often have to withstand much in the way of chemical attack. There are many chemical resistant wall coatings for specialty applications as well but they are not your typical “paint”. Most exterior wall coatings are breathable so as to allow the wall to dry out if any water or condensation get into the wall cavity, which is an important consideration.
Floor coatings have one performance area in particular that will far exceed a wall coating’s performance so it’s especially important to choose the correct coating for this type of application. The obvious difference is abrasion. As few people walk or drive on walls, abrasion isn’t an important criteria however it is an extremely important criteria for horizontal surfaces. Not only should abrasion be taken into account, the exact type of traffic as well as the extent of that traffic are both important considerations e.g. pedestrian, vehicular, commercial, residential etc. On top of the expected traffic, chemical resistance is much more of a concern as any spill will not only be more likely to hit the horizontal surface it will also dwell on that surface until it’s cleaned up so the chemical is far more likely to cause damage to the coating and potentially the substrate underneath it.
Chemical Resistant Coatings
Technically speaking, all substrates will come under some sort of chemical attack which ultimately can cause damage to the underlying substrate, which shortens the lifespan of the substrate. A true chemical resistant coating can withstand the harshest and most aggressive chemicals for a period of time. These coatings must be suitable for not only the chemical it is expected to withstand but also the substrate itself. Without knowledge of the actual chemical type, it’s concentration, temperature, type of exposure e.g. intermittent or submersed, and length of expected exposure to said chemical it is difficult to recommend the appropriate coating. Solvents, alkalis, acids and chlorides are among the many chemical types that can cause harm to any substrate and must be protected against.
Sealers can be classified into two distinct types, penetrating sealers and film-forming sealers. Many film-forming sealers penetrate to a degree but will also leave a film on the surface of the substrate to act as a physical barrier to whatever you’re trying to seal against. Penetrants absorb completely into the pores and leave no exterior surface film. There are advantages and disadvantages for both types from both performance and aesthetic perspectives. Be careful when choosing a sealer as there are many subtypes within the two categories that are temperature or substrate dependant with varying degrees of effectiveness or aesthetic variation like sheen level for example.
Tools and Accessories
Unless you’re Jackson Pollock, you will likely need a wide array of tools and accessories for any coating project. The right tool can make all the difference in the world as far as the look of the finished project and will certainly save you time and frustration during the job. Brushes, rollers, paint trays, anti-slip additives, solvents (thinners), scrapers, mixing paddles, painters masking tape, sprayers and many more accessories are all available at CDS to aid in any coatings job.