Do you need to sand or polish a concrete surface, e.g. a countertop? Are you wondering whether you need a specific equipment for the job? There is no clear answer to that, it actually depends on the size and strength of your concrete surface. If it’s just a small countertop with a comparatively fine surface, you might consider sanding it by hand with diamond pads. Some DIYers even share in forums and on YouTube that they have used their regular orbital or palm sander for the job.
This might be working well for one-off renovations and small pieces. However, palm sanders are primarily made for softer materials like wood or plastics. For the use on cement and concrete, there are specific grinders and sanders on the market. There are at least 5 reasons why you should consider using a concrete grinder for your project: More Power, facilitation of wet sanding, an optimized handling, thus higher convenience, and all this at a reasonable price.
Let’s discuss these points in more detail:
With an amperage of around 5-6 A, regular palm sanders are simply not powerful enough for challenging jobs on concrete surfaces. Concrete sanders are more powerful, starting at 7 A, which is more suitable for finer sanding and polishing tasks, and going up to 10 A and more, which is required for working on harsh surfaces.
2) Wet sanding
Concrete grinders often have either a water feed system or a vacuum adaptor, depending on their area of application. As wet polishing is generally recommended for concrete, you will value the precise water supply and application of built-in systems. Otherwise, you would have to manually handle a hose and the grinder at the same time – an inconvenient and potentially dangerous exercise: remember what happens if water meets electricity.
Most concrete grinders come with two handles: a top and a side handle. This will help you do the job in an ergonomic way, particularly when you are working on a wall: You will have to use the tool in a tilted angle without further support – a good ergonomy will prevent from quick fatigue and allow you to keep on working for a longer time and in a more convenient way.
How powerful a tool is an important driver for the ease of the work and the speed of your progress. Even entry-level concrete grinders will enable you to work faster and more efficient than palm sanders or even hand sanding pads or sand paper could do.
Obviously, the cheapest way of doing concrete sanding is to avoid buying any new tools. But if this implies the risk of overloading or breaking your existing equipment, you will want to think twice about it. In fact, concrete sanders for use around the house are not too expensive, you can even buy decent ones for as low as $180. The experts from ConcreteSanders.com recently reviewed some of the best-selling hand-held concrete grinders in the US – two of them at prices in a range between $180 and $250, and both of them performed quite well (read the full ). These are entry-level tools that are good enough for the vast majority of do-it-yourself project. For grinders with a popular bran – such as Makita, Dewalt, Bosch etc. – and (semi)professional tools, you would have to double that amount though. For a one-time use, you might consider renting such a tool from local home improvement or renovation stores. If you are using the concrete grinder regularly, buying an intermediate to professional level grinder could be a good investment though.
As you have learned, there are some good reasons for concrete grinders: these power tools come with a more powerful motor than regular sanders and grinders which will allow you to work more efficiently. An optimized usability and the integrated water supply facilitate the ease of work and the quality of the outcome. All these aspects might not be too relevant if you have only small cement surfaces to sand – you could still do it by hand after all. If you have a large concrete surface or a number of pieces to sand or polish though, you will probably find that a concrete sander is well worth the investment.