How to Shape a Surfboard

Learn how to use the tools that you will need and practice using them on practice boards before getting to your surfboard. You don't have to create a surfboard shape, just get used to the tools.

Choose your board template. The shape of your board will differ based on the type of surfing experience you want. For instance, long, flat, thick boards are good for small waves, whereas narrow, thin boards with a bottom curve work well in big waves. Fin placement changes the radius on your turns while you are surfing. Choose round rails if the water is choppy.

Draw the template out on 30-pound roofing felt if you did not purchase a template. If you are replacing or reproducing a board that you already have, lay the board on top of the felt and trace it using a silver marker. Trace the board and fins. Check the alignment of the nose and tail and measure the template from the center line to ensure that it is symmetric. Mark the location of the fin on the felt and cut out a hole where the fin will go using a box cutter.

Select a blank that is close to your template shape. Choose one that is wider for your first board so that if you make a mistake you have enough foam to fix it. Find a firm board that will give you some leeway while you are learning how to use your tools.

Position your blank on sawhorses, a rack or a sturdy table with the top facing up. Measure the length and width of the board using a tape measure. Add 1/8 inch to each measurement in case you need it for correction.

Place your template on the blank and mark dots along the lines of the template using a pencil. Cut out your board shape using a hand saw.

Turn the board over, smooth out the bottom using a planer and shape in the rocker. Start with one side until you have the shape right. Trace the design on a piece of paper and move to the other side. Move to the top of the board and smooth it out. Continue to plane the top of the board until it is the thickness you desire.

Shape the outside edges, or rails, using a sheet of sandpaper. Drape the sandpaper on each side and slide it up and down the edges of the board until they are smooth and round.

Sand all the rough edges from the board on both the top and bottom. Your board should be smooth with no rough edges anywhere from the planer. Paint your board if you are using clear fiberglass and resin, or add color to your resin mixture in Step 11.

Add fiberglass to your board. Cut the fiberglass so it has about 1 inch of overhang on each side. Cut a slit at the nose and the corners of the tail. Lay fiberglass sheets over the top of your blank. Mix your resin, color and catalyst and pour it over the fiberglass sheet. Move the resin around with a sponge so that the entire sheet of fiberglass has resin on it and adheres to the board. Work the resin slowly into the rails, but do not let the resin run on the rails. Use long strokes from the nose to the bottom of the board to work the resin into the bottom of the board. Move a light along the board to check for dry spots in the fiberglass. Let the board sit for an hour while the resin dries.

Turn the board over and repeat Step 10 on the bottom of the board. Overlap the edges of the fiberglass and trim the excess.

Purchase your fin with a fin box. Purchase a fin or several removable fins so that you can adjust your fin location and type as the waves change.

Turn your board back onto its top, so the bottom faces up, and place your template back on the board. Mark the locations of the fin boxes. Cut your fin boxes using a router. Tape around the fin in the fin box with chemical-resistant tape so resin will not get onto it. Slip the box into the area you just cut out of the board, but do not push it all the way down. Adjust the width or length of the hole as needed. Remove the box from the hole.

Cut two strips of fiberglass cloth that are 1 inch wider and longer than your hole. Lay them on wax paper and add resin to them. Sponge the resin evenly on the strips and mix it around. Lay the cloth over the hole and pour the rest of the resin mix around the edges of the box. Push the fin box all the way into the hole so the box is flush or sticking up only slightly above the hole. The fin box will push the fiberglass cloth into the hole, leaving excess cloth outside and under the box edges. Do not let any resin get into the box, and wipe up extra resin with a paper towel.

Set your fins into the fin boxes and tape them at the proper angle with 1-inch masking tape from fin to fin if you are using double fins. Use a fin angle template to set the fins to the right angle. Let the resin dry.

Sand any bumps and creases out of the fiberglass using a drill and sanding disk. Sand the entire board until it is smooth. Move slowly and do not push on the sanding disk. It should lightly touch the board. Hand-sand the rails. Continually remove the dirt and dust so that you can see how the fiberglass looks and what areas need more sanding.