High Solids/Low Solids Coatings

HIGH SOLIDS VS. LOW SOLIDS COATINGS

Q: Is there any difference in product quality and appearance when one compares high solids and low solids coatings?

A: When you refer to "high solids" coatings, I presume you are referring to coatings that meet EPA limits, such as 3.5 lbs/gal, 2.8 lbs/gal ,etc.?  Similarly, when you speak of  "low solids" coatings, I assume that these are non-compliant coatings with higher VOCs?

During the 1980s and '90s the paint industry made an all-out effort to develop compliant coatings that did not compromise the physical and chemical performance properties that we enjoyed with the existing non-compliant coatings.  To a great extent the paint vendors met this challenge, and there are some technologies in which the manufacturers even surpassed the performance properties of the "old" systems.

On the other hand, the application properties were often compromised.  Even current compliant coatings are often more difficult to apply than their non-compliant cousins of the ‘80s and '90s.  It’s no secret that high solids coatings are more difficult to apply at low film thicknesses than we could achieve with low solids coatings. Further, many painters still struggle to apply these coatings using HVLP guns, without getting “orange peel” finishes.  Consequently, during the past 15 years the public has unconsciously come to accept that many non-automotive finishes simply come with the orange peel appearance.  Autobody shops often complain that they cannot achieve “automotive” finishes with high solids coatings and this is a problem with fussy customers.  Other application problems also exist.  For instance, high solids coatings often need longer curing times; they easily produce runs and sags if the application is not well controlled, and plural component coatings tend to have shorter pot lives.

To summarize, for the most part, you can expect the chemical and physical properties to be much the same as the old systems, but in many cases appearance and application properties have been compromised.

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