Whenever time and resources allow, painters typically achieve the best coatings results from applying both a primer and a topcoat. Once this route has been chosen, the next important step is to select the best primer/topcoat combination for the application. To help coaters make this decision where metals protection is concerned, Cortec® Corporation recommends these top-three primer-topcoat combinations from its portfolio of Micro-Corrosion Inhibiting Coatings™.
For those seeking extreme protection in harsh outdoor, unsheltered applications, Cortec’s VpCI®-396/VpCI®-384 combination takes the frontiers with Cortec® solvent-based coatings system. VpCI®-396 is a fast drying, solvent-based moisture cure urethane one coat primer that can be applied DTM (direct to metal). Its complex chemistry offers protection that competes with most paints and zinc-rich primers. VpCI®-396 primes the way for application of VpCI®-384, a solvent-based urethane topcoat that rivals other big-name urethanes on the market and offers excellent adhesion to moisture cure urethanes like VpCI®-396 primer. It has a high gloss, excellent hardness, extremely good flexibility, and excellent solvent resistance. VpCI®-384 is a 2K (two-component) system, which adds another step to the process for mixing. However, this extra effort pays off due to the special cross-linking action that takes place between the two parts for greater durability in the long run. Cortec’s VpCI®-396/VpCI®-384 combination has excellent UV resistance and is recommended for use in the harshest conditions where a urethane topcoat would typically be applied, including coastal wind farms, power poles, tanks, and bridges.
While solvent-based coatings are sometimes needed to withstand extreme conditions, water-based coatings are often preferred for environmental or worker advantages. For example, water-based coatings generally have lower VOC than solvent-based coatings and are typically easier to clean up just with water. Fortunately, Cortec® has developed many good water-based Micro-Corrosion Inhibiting Coatings™ with exceptional protection. The first go-to water-based option is Cortec’s VpCI®-395/EcoShield® 386 combination. VpCI®-395 is a fast-drying water-based epoxy primer. As a 2K system, it has special crosslinking advantages for increased durability. Another advantage is its low VOC of 0.2 lbs/gal (24 g/L). EcoShield® 386 is the optimum option for a water-based topcoat and shows exceptional corrosion protection in salt spray testing. EcoShield® 386 provides UV resistance and therefore can be used as an outdoor coating. It can be applied clear or matched to most custom colors.
Single Component Water-Based Primer/Topcoat
For those who want to go the water-based route without the extra hassle of mixing a 2K primer, Cortec® also offers a good single component water-based primer/topcoat combination for corrosion protection in harsh conditions. VpCI®-375 is a water-based acrylic one coat DTM system that is resistant to sagging or running and forms a tough protective barrier. It offers UV resistance when dried, providing optimal outdoor performance without cracking or chipping upon prolonged exposure to sunlight. Although VpCI®-375 can be used as a topcoat if desired, it is even better paired with EcoShield® 386, Cortec’s outstanding single-component water-based topcoat.
Coating System for the User
Industrial painters will have different needs, restrictions, or preferences that factor into their final decision. Whatever the parameters, these three combinations are great ways to go for excellent performance with options for environmental or user benefits, 2K durability, or 1K convenience