Next boards I will be shaping are two 9’2" longboards. I posted about the design a few months ago in regards to the outline, rocker, and fin box placement. Now I’m wondering about the bottom contour and how exactly to shape it. I want them to have a rolled bottom with some nose concave, and I’ve never shaped a rolled bottom before. My first instinct is to make long planer passes on either side of the stringer and progress them outward towards the rail, the same on both sides of the board. More cuts to get the width to the rail first, then get further from the stringer. I hope my explanation makes sense how I see it in my head.
After this would I do the nose concave? Once the bottom is rolled. I’ve seen people take a template and draw a circle/egg shape for the nose concave, tape it off, make a few planer passes and clean up the concave with a sureform or sanding block right to the tape line. Just not sure if after rolling the bottom is a good order to put these steps in.
Make a pass down the stringer both deck and bottom. This pass should be a pass that will leave foam and wooden stringer flush/level. Instead of starting at the stringer and working out as you stated; Start ar the rail and work toward center. This is normal shaping practice. When you reach center, take a sanding block and level,getting rid of planer cuts. Then go back at it with planer from rail to center. Deep cuts at the rail, shallower cuts as you plane toward center. Then take a sanding block/soft pad with sandpaper and then screen to it for clean up. Tape off you desired placement for the nose concave. If you have the skill, plane in your concave. If not put it in with a Surform or sanding block. Screen the whole thing with a foam pad and screen. A brief tutorial and not detailed, but that’s basically it.
Would it be appropriate, once I have the bottom level and the thickness and foil dialed in, to make the rail cut for the rolled bottom much deeper (as deep as the final pass) and just blend it to the center? I can understand this process with the way you explained it, but if I were to roll the bottom after foil/thickness, which seems most comfortable to me, I would want to avoid taking down the stringer any more and messing with the thickness.
I used to plane the board to thickness and then shape the rocker in, but I’ve learned that shaping the rocker curve first and making a final set of passes to the desired thickness ensures a smoother, more accurate level bottom.
Also, cheers for all the advice on bascially all my posts.