Why grinding edges is more difficult than open areas
Adequate concrete surface preparation is vitally necessary in order for a coating or adhesive to thoroughly bond to the floor surface, so you definitely don’t want to neglect the edges.
In areas where large, walk-behind grinders, scarifiers, or shot blasters can reach, the bigger the machine the more efficient the process. In areas where a bond is equally important but access by the large equipment is not possible, smaller machines need to be used to provide the required preparation.
In the case of edges around flooring protrusions, openings, or against walls, machines made specifically for this purpose should be used. They can be used wet or dry depending on the manufacturer and the industry, but specifically in this article, we will focus on dry edge-grinding.
Dry grinding any concrete surface is now regulated by OSHA and is required to be a dust-free process. This means any edge-grinding machine must be equipped with a dust shroud that allows a vacuum to capture the dust before it can escape the cutting area. Visible emissions carry a heavy fine by OSHA and present a health risk so having proper dust collection equipment is compulsory.
Edge-Grinding Machines have Definitely Improved Over Time
The grinding machine itself is one that is usually 110V and holds a diamond cutting wheel. The cutting wheel spins parallel to the floor at an average speed of 6,000RPM. While styles of wheels can vary, a common grit for a basic #2 CSP is 30-40 grit. Sizes can range too but the common size in diameter is 7-inches.
Past applications of edge-grinding usually meant the operator held the machine in hand and performed the work while kneeling. This led to operator fatigue in both the knees and lower back. As the worker continued, he or she became fatigued from the required posture instead of the actual grinding process.
Now, more modern edging machines are designed for the work to be performed while comfortably standing. This greatly reduces operator fatigue while increasing the quality of work and its overall productivity.
Four Simple Steps for Successful Edge Grinding
- Machine operation is first begun by attaching a suitably sized dust collection hose to the machine and switching vacuum to on.
- Once the vacuum is started and a suitable PPE is in place, the edge-grinder is switched to on and the machine is immediately moved across the concrete surface.
- Move the edger in a linear direction with subsequent swirling motions over the edge to avoid any lines or gouges from taking place in the surface.
- Repeat motion until entire edge is completed.
The object is to profile the floor uniformly without leaving depression marks or excessive scratches. To perform the actual work without damaging the concrete beyond the required CSP takes some practice. The machines are not too complicated to comprehend and are well balanced, but like any new technique, practice will make perfect.