A skilled woodworker explains everything you should be aware of about sandpaper for wood so that your next project can be completed flawlessly.

Sandpaper is everywhere throughout the woodshop, and since there are numerous variations, it can be confusing to newbies. Do you prefer to sand up to 220 or 180? What do those spongy sanding blocks used for? Why do some sandpapers have different hues?

This world could be a vast area and hard to understand But let's focus on what's commonly beneficial for woodworking. We'll provide you with all the info you need to succeed with your sanding efforts on that next piece of woodwork.



Understanding Sandpaper for Wood: Grit Size

The first thing to know is the grit size. Sandpaper is simply tiny particles, usually composed of metal compounds that are adhered to a backing, usually paper. The size of the particles determines the size of the grit.

The smaller it is, the greater the particle size and the more coarse the sandpaper. This will remove material more quickly, leaving rougher edges. The higher the number, the smaller the particles that leave a smoother finish. There's no limit to how long or precise you could sand. But for this article, we'll focus on four main grit levels.

• Coarse grit = 36 to 80: This will be ideal for quick removal of stock, for example, smoothing the edges of slabs or sanding rough-sawn areas.

• Medium grit = 100 to 180: This removes mill marks off your machines and leaves the appearance of a clean surface. Certain finishes recommend using sandpaper that is 180 grit so that the finish can "bite" onto the surface of the wood. So ensure you've reviewed the instructions prior to applying your paint.

• Fine grit = 220 to 400: We typically sand it up to 220. This allows us to achieve the highest quality of grain on the wooden surface. We can sand the wood with 400 grit sandpaper or similar cloth that is abrasive prior to finishing to provide the most smooth, beautiful finish to the piece.

• Polishing grit = 600 and up: The grits used to polish finished surfaces are used only in wood shops.

Extra information: Europe has a different scale for grit than that of the U.S. If you ever see the grit size marked P-180 or P-220, it's Europe. Although it's not exactly the same, it's similar enough. We would say it's pretty much identical.

Hand Sanding vs. Machine Sanding

Based on the setup you use for sanding, it is possible that you will require different kinds of sandpaper. The most popular are the following:

Sanding by hand

• Sheet sandpaper: It is possible to get sanding sheets in a variety of dimensions; however, the largest and most popular are 9-in. x 11-in. and 9-in. x 3-in. They typically come with a smooth back and are quite stiff when folded. They are able to squeeze into corners and crevices that machines cannot let you get into and allow you to sand each sq inch in your work.

• Blocks for sanding: These semi-rigid sponge-like blocks are typically found in hardware stores at significant discounts over the sanding sheets. Although they can be useful in applications (drywall sanding is one that comes to mind), they're not the most efficient when it comes to woodworking. Don't throw away your money. Buy sandpaper sheets, and then make your own blocks to sand!