Why surface preparation is important
I often get asked why we spend so much time and resources on surface preparation. The answer is actually pretty simple. Because it is the only way to ensure that our coatings have a proper mechanical bond to the concrete, the surface preparation is the foundation of the epoxy flooring, and if it is done improperly, all subsequent efforts will essentially be done in vain. There is no type of special materials, primers, or solvents that can make up for inadequate prep work. Believe me, if there was an easier way, all concrete coating contractors would do it. The fact is, concrete grinding is the unsexy and often the most time-consuming and labor-intensive portion of the entire process. But it is arguably the most important part when it comes to the performance and durability of the coating system. So how is this done? At Top Gun Garage, we use either Diamond Grinding, Shot Blasting, or a combination of both on every floor. The choice of the two depends on the condition and hardness of your concrete.
SHOT BLASTING VS DIAMOND GRINDING
Based on our technician’s assessment of your concrete, the choice of shot blasting or diamond grinding will be made at the time of installation. The goal is to achieve a manufacturer-specified concrete surface profile (CSP). This is just a fancy way of saying how coarse the concrete surface is after preparation. Most 100% solids epoxy requires a CSP rating between 3 and 5 on a 1-10 scale.
The most effective way to do this is via shot blasting. Shot blasting is done with a specialized machine that utilizes a metal media that is projected in an even pattern onto the concrete. Think of a sandblaster that uses small metal ball bearings instead of sand. This removes any existing coatings and the top layer of concrete and leaves the concrete profiled and ready to wick in the new material. All of the dust that is created during this process is removed with our high-powered dust extraction system with a HEPA filter.
Shot blasting is virtually dust-free. All of the areas along the edges and in the nooks and crannies are then done with a handheld diamond grinder that utilizes the same dust extraction system. It is important that all areas that are being coated receive adequate profiling. There is one pitfall to shot blasting, however. Due to the aggressive nature of shot blasting, some concrete surfaces are too soft for shot blasting. In that case, our technicians will opt for diamond grinding.
Diamond grinding is done with a commercial-grade grinding machine that uses man-made diamonds to abrade the concrete surface. The machine looks similar to a large push mower and has the ability to remove the top layer of concrete and achieve a CSP of around 3. The diamond grinding process takes about the same amount of time and effort but prevents the softer concrete from being damaged.
There is also the ability to adjust how much material is taken off and the final profile that is achieved with the use of different grits and hardnesses of the diamonds. Our diamond grinder also uses the same dust extraction system to collect any dust during the process. The surface is then ready for final cleaning, and repairs of any imperfections are performed prior to installation of the epoxy flooring. I hope this helped to answer the question about why we take surface preparation so seriously at Top Gun Garage. If you have any questions, feel free to reach out using the form submission below or by phone at 239.488.700.