Centuries ago, the Chinese discovered that you can efficiently polish and smooth materials by gluing crushed shells and seeds to a piece of parchment and rubbing that parchment against the material. Centuries later, we are still using this technique everywhere, from large, industrial factories to small, do-it-yourself projects. Sandpaper has changed a great deal over the years as we’ve evolved it to fit our needs. But what exactly is sandpaper?
Even though the name has stuck through all these years, sandpaper that is actually made from sand, or quartz, and paper is not common anymore. Over the years, people have realized that there are other, stronger minerals that can not only get the job done, but can get the job done quicker and more precisely, depending on what kind of job you are doing.
So, what is it exactly? It’s a type of coated abrasive, which is a general term used to describe all kinds of tools used for sanding, cutting, refining, and polishing. Most all coated abrasives are comprised of three things: an abrasive, a backing, and an adhesive to help it all stick together. The abrasive layer can be made from either natural minerals or synthetic ones. The backing is typically a flexible one, since the user usually needs to move the coated abrasive in many different directions and not just along a straight edge.
What Mineral is Used In Sandpaper?
Though quartz is hardly used anymore as the abrasive, there are usually four different types of minerals that make up sandpaper.
- Aluminium oxide is perhaps the most commonly used as it used primarily for woodworking projects. If throughout this article you pictured a piece of rough, brownish paper, then you’re probably thinking of aluminium oxide sandpaper. Aluminium oxide is actual a for of Sapphire and Ruby which is why it is so hard.
- Garnet is another kind of mineral used, and it gives the sandpaper a bronze or reddish color. Garnet sandpaper doesn’t last as long as aluminium oxide sandpaper, but it is known for giving the product a much smoother finish.
- Alumina zirconia, also known as ceramic sandpaper. Of the four minerals, alumina zirconia is the most durable and roughest mineral. Oftentimes you have to be careful when using ceramic sandpaper as you might end up sanding away more than you intended. It’s one of the more expensive kinds of coated abrasives, but it gets the tough jobs done.
- Silicon carbide, which is the second most common abrasive after aluminium oxide. Silicon carbide is a far cry from the long-lasting ceramic sandpaper, but it is more versatile since it can be used in both dry sandpaper and wet sandpaper.
There are other abrasive materials that can be found in sandpaper, including flint, glass, and corundum. Corundum in particular is one of the toughest sandpaper abrasives out there and is more commonly found in industrial settings rather than non-industrial ones. Aluminium oxide is in fact the synthetic form of corundum, serving as a testament to how easily adaptable the material is to different project, such as wood, metal, and plastic.