Today I decided to share some tips about choosing and using sandpaper. If you’re an advanced DIYer or woodworker, then you might think this is obvious information. But I’m always stunned by how many people spend so much time and effort building a project they can be proud of, only to sabotage the end result by not putting the same effort into the finishing steps. The first step to a beautiful finish is preparing the material (wood or metal) to accept the finish – typically that includes sanding. I won’t attempt to cover every detail, but I will go over the basics that will help you achieve a beautiful finish on your next project.

Step 1: Select the correct type of sandpaper.
Choose sandpaper that is intended to be used on the material that you are working with: wood, metal and so on. Yes, there are different kinds and it does make a difference. Most sandpaper packages are labeled with the intended application.

Step 2: Select the grits.
This number printed on the back of sandpaper is a universal gage that refers to the grit or roughness of sandpaper. It’s the actual number of particles applied to 1 sq. in. of paper at the time of manufacturing. Thus, the lower the number, the larger the particles and the rougher the sandpaper; on the contrary, the higher the number, the smaller the particles and the finer the sandpaper. For example, a piece of 100-grit sandpaper has 100 particles on a sq. in. of paper. Sandpaper used for plastics and acrylic polishing can go as high as 20,000 particles a sq. in. Sandpaper grits loosely fall into the following categories:
Coarse: Used for shaping, 60 to 80 grit
Medium: For smoothing, 100 to 180 grit
Fine: For finishing, 220 to 400 grit
Extra-fine: 600-plus grit

When purchasing sandpaper, you will find it packaged as individual sheets of one grit size of paper or an assorted pack with a few sheets of three or more different grits sizes. For most woodworking projects, you should use a progression of sandpaper grits from coarse to medium to fine. If the material is relatively smooth, then you can usually start with a medium grit.

Tip: When sanding, always sand with the grain of the wood, not across the grain

Step 3: Run through the grits.
In the carpentry world, you will often hear the phrase, “Be sure to run through all the grits.” This means you should work your way toward your finished piece by progressively moving up in grit. For example, if I start sanding a piece with 150-grit sandpaper, I have to progress to 240 before I hit it with 320. Skipping over an intermediate grit will leave scratches behind. The grits are designed to progressively work the piece to an even, smooth finish with each level breaking down the one before.

Tip: In between finishing coats, lightly sand with high grit (400) for a great finish!

Sanding sponges are blocks of sponge core that is wrapped or coated with sandpaper or sanding particles. They are commonly available at home centers and hardware stores in medium, fine and extra-fine grits. They conform nicely to the hand and work well for sanding contours and into corners or other hard-to-reach areas. 

No-slip tip: I like using sandpapers that feature a no-slip backing. It not only saves time but will also save your hands.

Are you still hungry for even more information about sandpaper? Check out this Basic Guide to Sandpapers from HANDY Magazine.

See images of Carmen’s designs, woodturning and creative projects at:
www.carmendelapaz.com
www.youcandoitmag.com