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

Sandpaper is a common item within the shop and with numerous variations that can be confusing to the novice. Should you sand at 180 or 220? What do the spongy blocks of sanding for? What are the reasons why some sandpapers come in different shades?

Abrasives could be vast and difficult to understand. However, let's keep to what's helpful when working in the woodshop. We'll provide you with all the details you require to succeed with your sanding efforts on that next piece of woodwork.



Understanding Sandpaper for Wood: Grit Size

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

The smaller it is, the bigger the particle size and the rougher the sandpaper. It removes the material faster, leaving rougher surfaces. The higher the number, the smaller the particles, and the smoother the finish. There's no limit to how long or precisely you are able to sand. But for this article, we'll focus on four primary grit ranges.

• Coarse grit = 36 to 80: It is ideal for quick removal of stock, like smoothing the edges of slabs or sanding rough-sawn areas.

• Medium grit = 100 to 180: This removes mill marks off of your machines and leaves an overall clean and clear surface. Certain finishes suggest only using sandpaper that is 180 grit for the finish to "bite" onto the surface of the wood. So make sure you follow the directions before placing your finishing.

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

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

Extra bonus information: Europe has a different scale of grit than the U.S. If you ever see the grit size marked P-180 or even P-220, this is Europe. European scale. Although it's not the exact equivalent, it's similar enough. We would say it's pretty much identical.

Hand Sanding

Based on the sanding configuration you have, it is possible that you will require different kinds of sandpaper. The most commonly used are the following:

• Sheet sandpaper: It is possible to find sanding sheets of various dimensions; however, the largest and most commonly used are 9-in. x 11-in. and 9-in. x 3-in. They generally come with a smooth back and are relatively stiff when folded. They can be able to get into corners and crevices, which machines cannot reach, allowing you to sand every sq inch in your work.

• Blocks for sanding: These semi-rigid soft blocks are usually found in hardware stores at significant discounts over the sanding sheets. While they are useful for applications (drywall sanding is one that comes to thoughts), they're not the most efficient for woodworking. Don't throw away your money. Purchase sandpaper sheets and create your own blocks to sand!