Have you been confused about the term "Solid Content"? Or ever felt frustrated of even overwhelmed in conversation with a sales rep, and they keep throwing out terms and numbers like 70, 85, acrylic, polyaspartic, 90, polyurethane, epoxy, 100%, and so on until you get are at the point of pulling your hair out and shouting "What does it all Mean"!? While all these terms and numbers are important, the concept does not have to be that difficult. In fact, it is a fairly easy theory to gasp if we start from the beginning.
The first thing we need to understand is the difference between the solids and the carrying agent. This is what all the numbers were referring to.
The Solids-The word "Solid" is defined as; a substance or object that is solid rather than liquid or fluid. So, obviously that bucket of cure & seal at your shop or the kit of epoxy you just picked for your next job is a liquid form and is definitely not solid. This is why we use the term "solid content" to describe the part of liquid that will become solid after it has been applied and had the proper time to harden. For example, if you are applying a coating that has a solid content of 85%, only 85% of that liquid will stay behind as solid film and 15% will evaporate off. If you are spraying an acrylic sealer that is 25% solids, 75% of whatever you sprayed on the concrete will evaporate and only 25% will actually form a solid film.
The Carrying Agent- So what about the part that evaporates? What does that part do, And why do we need it? This part of liquid is referred to as the carrying agent or the carrier. The Solid content of concrete sealers and coatings are made up of a variety of different resins that all need to be spread out at a certain rate per square foot. These different resins also have differences in their workability, and some of them wouldn't be usable in their pure form. This is where the carrier comes in to play. It is what allows you to work with the resin and spread it out at the proper rate. The main two carrying agents found in concrete sealers and coatings are water and solvents. Most of the odor associated with sealers and coatings come from the carrier, this is why you generally see most of the low odor options to be water based. Although in the concrete coatings world things are changing fast and we now have a great low odor solvent based option as well.
Understanding the relationship between solid content and carrying agents helps to paint a clearer picture of why a concrete sealer or coating will behave in a certain manner. Things like dry time, breathability, sheen, bond, and workability are all affected by the same amount of solids that a coating or sealer contains. Over the next few weeks, we will take a deeper look at the different kinds of carrying agents as well as sealers and coatings.
Please feel free to send us an email with any questions you might have about concrete sealers and coatings. Jeff@deco-cretesupply.com