Sandpaper Blocks Materials: - 2 empty thread spools - 2 pieces of wood (approx. 2" X 4" X 4") - Sandpaper - Wood glue - Scissors Method: Cut two pieces of sandpaper to fit the blocks. Glue on each block and let dry. Center each spool on the other side of each block. Glue and let dry. Rub blocks together to make a unique sound.