Ever since I watched Marc’s Scraper Sharpening w/ William Ng video I’ve been meaning to build some of the sanding blocks that made a brief appearance at around the two minute mark. The design is incredibly simple, easy to make, and fit a 1/2 sheet of sandpaper.
To build one take a piece of 3/4″ birch plywood and cut it into 3 1/4″ x 5 1/2″ blocks. Next cut some 5 1/2″ x 1″ strips of 1/4″ ply. Finally cut a 3/4″ deep grove in one of the long sides of the blocks that’s a bit oversized for the 1/4″ ply.
To get the grove perfectly centered I started by aligning the fence of my table saw to cut a grove roughly in the center of the block. I then cut the grove with one side against the fence then ran the oposite side trough to perfectly center the grove. Next I snuck up on the fit by moving the fence away from the blade slightly, cutting again, and repeating until I got the perfect fit.
Now fold a piece of sandpaper around the block, tuck the ends in the grove, and wedge the strip in to keep everything secure. The friction of the sandpaper will keep the strip from slipping out. It’s also a good idea to write the grit of the sandpaper in pencil on the strip so you don’t have to keep taking the block apart to remember which sandpaper is in it (something you see William do in the video.)
These are so easy to make it’s worth banging out a whole batch and keeping one for each grit of paper you use. If you want something with a bit more give, try gluing some cork, felt, or rubber to one or both sides and adjusting the block size to fit.