What we are trying to achieve is an even curve, going from a flat deck into a quarter round vertical rail. At the tail protruding 30cm forward towards the nose of the board, we are trying to produce a nice boxy rail section. This helps keep the water from traveling onto the deck whilst gibing or carving hard.
Use a 3/8th beading bit (quarter-round) to radius the deck side tail edge producing a quarter-round rail, 30cm from tail traveling towards to nose. If the router cut marks the deck surface feather any difference by sanding – remove the small step that the router tool leaves. The first boards that we made, all had boxy rails like this and they worked perfectly; however, we achieved better performance by using progressive rail shapes along the entire length of the board. Plus the boards look more aesthetically pleasing to the eye.
Using a swept router bit, route around the rest of the board rail using the router bit CMT Ref: 856.601.11 Leave a 10cm space between the tail quarter round and where the swept router begins as we will feather these two sections together using a hand plane and a flat sanding block.
Removing excess tail weight & increasing tail flex
Reduce tail thickness to increase flex in the rear section of the board & remove excess tail weight. You need a guideline to work to, so I’m choosing a half-way point. Then using my middle finger & pencil I’m going to create a line which is parallel to the hull on the tail of the board – this is my maximum sanding line on the rail.
Mark an 80mm guideline from the tail on the deck. Join the two lines with the orbital sander to form a slanted or curved tail depending upon your preferred shape preference. Obviously you do not want to sand beyond either of the two guidelines if you want your board to remain symmetrical. This is not difficult, just carry out the sanding in an orderly and slow fashion then, when you arrive close to the line stop and finish in the direction of the grain with a hand sanding block.
Shaping the nose section.
We need to make the nose rail section nice and rounded. Measure in from the nose 10cm / 4 inches along the center-line of the board. Then position the template on the 10cm mark and align it with the rail. You might have to use a clamp to clamp the template in place aligned with the rail towards the tail. Ensure that it aligns with the 10cm mark, then using your sharp pencil trace around the template.
Flip it over, rinse & repeat to mark the other side of the nose.
I’m going to extend the curve further down to where the rocker of the board starts so that we have a nice rounded rail all the way along the rocker line.
Using a hand plane, surf form and the sanding block, curve the rail and radius this section between the marked line and the outline of the nose.