Whenever time and resources allow, painters typically achieve the best coating 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 Corp. highlighted its top three primer-topcoat combinations from its portfolio of micro-corrosion inhibiting coatings.
Solvent-based primer/topcoat
For those seeking extreme protection in harsh outdoor, unsheltered applications, Cortec highlights its VpCI-396/VpCI-384 combination. VpCI-396 is a fast drying, solvent-based moisture cure urethane one coat primer that can be applied direct to metal (DTM). VpCI-396 primes the way for application of VpCI-384, a solvent-based urethane topcoat that offers adhesion to moisture cure urethanes like VpCI-396 primer. VpCI-384 is a two-component system, which adds another step to the process for mixing but offerscross-linking action that takes place between the two parts, which Cortec says leads to greater durability in the long run, according to the company. Cortec’s VpCI-396/VpCI-384 combination is recommended for use in the harshest conditions where a urethane topcoat would typically be applied.
Water-based primer/topcoat
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. Cortec recommends its VpCI-395/EcoShield 386 combination. VpCI-395 is a fast-drying water-based epoxy primer, and as a two-component system, it has special cross-linking advantages for increased durability, the company noted. Another advantage is its low VOC of 0.2 lbs/gal (24 g/L). 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 two-component primer, Cortec also offers a 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 the company says is resistant to sagging or running and forms a tough protective barrier. It offers UV resistance when dried.
