Water Based Sealers – New Standards for Safe Effective Concrete Sealing
One common misconception we come across is that people believe solvent based concrete sealer products are inherently superior in some way or another to water-based concrete sealers. When I ask people why they believe this is the case I get all kinds of responses ranging from “…everybody knows that!” to “won’t waterbased ones get washed away when it rains?”. One of my favourites is “because a wise old man (grandfather/uncle / old guy down the street) told me so”.
What is a solvent?
Before we go any further I need to qualify what is meant by a “solvent based” product. The Oxford dictionary defines a solvent as “The liquid in which a solute is dissolved to form a solution”. As such the most abundant solvent on earth is water and the biggest solution would be the world’s oceans. However, the word solvent is one that has been hijacked by the paint industry to mean something far more specific than it’s actual meaning. By convention “solvent based concrete sealers” or coating, is one that contains an organic solvent, that is one that is derived from oil. Well known examples include xylene, mineral turpentine, and “thinners”.
What does a solvent do?
Now, all types of coating contain, at a minimum, a binder (solute) and a dilutant (solvent). The binder, as the name implies, is what makes the coating stick to stuff. A coating needs to stick to whatever you want to coat and also to itself so it can form a continuous film. The dilutant is there to carry the binder in a liquid that can be easily applied and to physically disperse the binder enough to stop it from binding before it’s ready for use. After the coating is applied the dilutant evaporates away and the binder is free to do its thing.
So the ironic thing here is that ironically people make a judgement about the quality of a coating on the stuff that evaporates away! It doesn’t even exist in the finished product and as such has almost no bearing on the quality, performance or durability of the penetrating sealer or coating. It is far more important to consider the chemical properties of the binder when determining the quality of a penetrating sealer or coating.
Which solvent is the best?
The biggest consideration in deciding between water-based and “solvent” based therefore is cost, health & safety and impacts on the environment. In each of these key areas, water comes out on top. It is the most abundant solvent on earth, so it’s cheap and it can’t hurt you or the environment. Organic solvents , by comparison, re expensive to produce and use; plus they can be extremely harmful to your health and the environment.
The health effects of organic solvent exposure are many and diverse. Common isues are respiratory irritation, headaches and increased chemical sensitivities. More severe are mental health problems, infertility, cancer and even instances of sudden death! The biggest impacts to the environment from solvents are related to cleanup. You cannot just clean your equipment with water so you need to use more organic solvent to cleanup. Disposal of such residuals is costly and unfortunately many people don’t dispose of them as they should. Alternatively, many people just move to single use brushes and rollers that they throw out at the end of the job. These fill up landfill and leach the remaining traces of solvent into the groundwater.
Do the right thing. Choose top quality coatings that won’t harm you or the planet.