Sandpaper is an essential tool in any construction or DIY project. It works to either remove material, smooth or sometimes rough up surfaces. It’s definitely not a ‘one-size-fits-all’, there are different grits more suitable for different jobs. Here’s a guide.
Types of Sandpaper
To begin with, there are four classes of sandpaper grits: Aluminium Oxide, Garnet, silicon carbide and Ceramic. Aluminium Oxide Sandpaper will last the longest because the structure essentially self-renews. It’s actually quite delicate but when it crumbles, new soft edges form.
Garnet will wear out the fastest but produces the smoothest surface; often used to polish and finish wood.
Most common sandpaper sheets are made from Silicon Carbide – it’s the most robust and can handle harder materials such as metals and plastics.
Ceramic has the roughest grit and is often used for shaping wood or tiles.
Sandpaper Grits Explained
In essence, the smaller the grit number the coarser the sandpaper, and the higher the number the smoother. Coarse sandpaper is used for rougher surfaces, and finer sandpaper is used for finishing and smoothing surfaces. With jobs you often have to ‘go-through-the-grits’ where you start with the lower-grade grit and move upwards, removing the scratches from the previous layer until you end up with the desired results.
Different Sandpaper For Different Jobs
- Sanding down between paint coats – go for a 220 grit sandpaper
- Sanding old floors – try a 24 grit
- Polishing surfaces – anything above 400 grit would be ideal
- Preparing to paint a smooth surface – Start with an 80 grit and move to a 200+ grit
- Removing old varnish – 100 – 150 grit would be appropriate
- Sanding metals – try emery cloth
Also take into account the condition of the surface before you start as coarser sandpaper could damage some surfaces.
Sandpaper can come in sheets or blocks, as cloth tape as discs for hand power tools or as cloth sanding belts to use pneumatic belt sander machine. The grit and sandpaper type remains the same across all, they just come in different forms depending on how you need to use them. Sandpaper sheets are ideal when you don’t need to do a lot of sanding or have a small sheet. Sanding Blocks offer a more ergonomic motion when sanding. Hand power tools are great when you need to get in tricky spots or do big pieces of furniture. Woodworkers, whether amateur or professional, would be better off using a sanding machine either handheld or table top.