Surfing School - Shaping - Sanding Blocks
Sanding blocks are a seldom emphasized but extremely important part of every shaper's equipment set. These blocks are slightly different than those used by carpenters, and are normally hand made. The basic set for shaping consists of three blocks.
For your long block, take a piece of 3/4" pine or other soft wood about five inches wide and two feet long. To this, completely glue and staple an equally large piece of 50 or 60 grit sandpaper. The paper should be folded from the bottom to the top of the board where the staples or small nails are inserted. Nothing other than the sandpaper itself should touch the bottom of this board as glue bumps or other unevenness will cause depressions while sanding. This block is used primarily for bottom sanding.
The second block should be made from a piece of 1/2" balsa wood about 4" by 10" long. Cut a piece of carpeting slightly larger than the block and tape wood and carpet together with a few wraps of masking tape at each end. Sheets of different grade sandpaper can easily wrap around this block and held by hand while sanding. This block is used for most rail and top sanding.
The final block is not really a block at all, but simply a soft semi-circular sponge with a flat surface about 6" by 8". This is used with fine sandpaper screens for applying the final smooth surface to a finished blank. Only a screen is used by itself for the final rail sanding.