Cortec® offers a variety of VpCI® additives that formulators can use to boost the corrosion protection and salt spray performance of their own coatings. These additives are typically used at a much lower dose than others and are clean and efficient to add. However, the entire benefit of using a VpCI® additive is undermined when too much foam causes defects like pinholes, craters, and curtains. It is therefore imperative to know when a defoamer is needed to avoid these problems.
What Kind of Coating Are You Formulating?
The first sign that you will probably need a defoamer is when you are formulating a water-based coating. While water-based coatings often have important environmental and worker advantages, such as low VOC and easy cleanup, they almost always need a defoamer. This is less common in solvent-based coatings.
What Is the Target Application Method?
Another factor to consider is the expected method of coating application. Spray application is less likely to cause foaming problems, while vacuum coaters are notorious for creating “milk shakes”—paint with more foam than you know what to do with. Flow coaters also have the tendency to create “curtains” where entire strips of metal remain uncoated because an air bubble blocked the paint from flowing underneath that spot.
What Else Will You Be Adding to the Coating?
Coatings can contain dozens of different ingredients—each with a specific purpose—and can vary significantly from one formula to another. This means the defoamer that works for one coating may not work for another. For example, sometimes silicone defoamers may actually cause pinholes or craters due to how they interact with the other ingredients.
How to Choose the Best Defoamer
The best way to avoid foam and ensure that your Cortec® enhanced coating is a success is to talk with your defoamer supplier. Discuss the characteristics and target application of your new VpCI®-powered formula. Then try the recommended defoamers by adding them to the coating and doing a shake test or running them through a blender to see which one is best at reducing foam. It is also a good idea to apply the coating to metal to see how the finish is.
Maximize the Success of Your New Anticorrosion Coating
When you choose a Cortec® additive, the purpose is to make your coating perform better. One of the last things you want to happen is to have the coating fail because of too much foam. Next time you add a Cortec® VpCI® additive to your formulation, be sure to include a defoamer in the discussion to maximize the success of your new anticorrosion coating. Contact Cortec® for more advice on formulating coatings with VpCI® additives here: https://www.cortecadditives.com/contact-us/
Keywords: Cortec Coatings, coating additives, corrosion protection, salt spray performance, low VOC, water-based coating defoamer, silicone defoamers, how to choose the best defoamer, make your coating perform better, anticorrosion coating
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