Have you ever walked into a decorative concrete supplier and wondered why there are so many different solvents on the shelf? What do all these solvents do, and why do they have so many different ones? Understanding how solvents effect concrete sealers and coatings can be very helpful when working with these products. Solvents also have some other great uses in decorative concrete that will help solve problems when they arise.
Carrying Agent - In last week's blog we went over the difference between the solid content and carrying agent in a concrete sealer or coating. Now that we understand what these do, its time to dig deeper into what they are made of.
In general, concrete sealers and coating are either water based or solvent based. For water based products, the carrying agent is water and there is not really much to talk about there. Solvent based products on the other hand are a different story. They will behave differently depending on what kind of solvent used as the carrier. Acetone for example, is a very fast drying solvent. Xylene in comparison is slower drying. If you had a sealer that is loaded up with Acetone it would dry really fast. A sealer with a carrying agent that is slower to evaporate, will dry much slower. Keep in mind that we are just using this as an example and you will not find any sealers or coatings that only use one solvent as the carrier. Instead, it is normally a blend of solvents that make up this part of a coating. Dry time is not the only thing that determines why a certain blend of solvents are used in certain sealers or coatings. Things like VOC content, price, and the chemical makeup of the resin itself will all come into play. But, as it goes. The faster the solvent evaporates, the faster the sealer is going to dry.
Using Solvents to Fix Problems - Next week we will dive deeper into the resin part of concrete sealers and coatings. But for now, let's just say that acrylic sealers can be re-emulsified or melted with solvents and coatings cant be. In fact, even if you got a concrete coating to melt from a solvent. It would never dry back up and get hard again. So, this next part will only apply to acrylic sealers. Solvents can be an incredibly effective way of repairing existing acrylic sealer that has some sort of problem. A product like Rejuvenator is a great way of fixing sealer that has turned white, bubbled, or maybe it got rained on before it had a chance to completely dry. It can also work wonders on a high gloss sealer that has lost it's shine over the course of a year or two. Solvents are a much better fix then just applying more sealer. Putting more sealer on top of an existing sealer that already had a problem is never a good idea. Fix the problem first, and only put more sealer on if it really needs it. In many situations, Rejuvenator will take care of the issue all on its own. But, if you do need to add more sealer after the problem has been fixed, at least now you are using the sealer for what it was designed for. Sealing concrete. Not fixing problems. The solvent will also help to soften up whatever sealer is still left, and the new sealer will have a better chance of bonding. Almost like a primer. This solution obviously only applies to solvent based based acrylics and wont work for water based sealers. So, as long as the existing sealer was something solvent based, Rejuvenator would always be the best place to start when you are having a problem acrylic sealer.
Clean-Up- - When using a solvent based sealer or coating of any sot, you will need some kind of solvent for clean-up. If you are spraying acrylic sealer, Xylene or liquid Release work great for cleaning out you sprayer. Solvents are also ideal for cleaning tools after a coating job and Acetone is an awesome way to do a final tack wipe on a floor. Just remember when working with solvents inside, make sure that there are no open flames like pilot lights and always follow the safety precautions for these products.
Other Types of Solvents -
Denatured Alcohol can be used to create some cool effects in metallic epoxy like Liquid Metals.
Liquid Release is another form of solvent that gets used everyday in decorative concrete.
Solvent Retarder is the slowest drying virgin solvent we offer and can be helpful when trying to slow down a fast drying sealer or coating.
Knowing some of the different types of solvents and how the affect dry time will give a better understanding of why a concrete sealer or coating might cure faster or slower than another. Utilizing solvents for fixing problems and clean-up is also important for the decorative concrete contractor to be aware of.
- Jeff Hershberger
Please feel free to send us an email with any questions you might have about solvents or anything else relating to decorative concrete. Jeff@deco-cretesupply.com