Shaping the foam turned out to be a little more challenging than I had initially imagined. The lack of power tools and anything other than 60 grit sandpaper, attached to a sanding block (thank god for the sanding block), meant that I had to invest many hours of elbow grease to get any shaping done.
Ideally you would have access to tools such as an electric planer, an orbital sander, and a surfoam plane, etc. Not only would these tools give you the precision and speed to quickly shape a surfboard, they also have the appeal of making you look like a pro.
However, if the only tool in the box is sandpaper, do not fret, it is still possible to shape a surfboard. There are some perks to only using sandpaper. For example, you get to spend more time and effort shaping your board, mastering the art of sanding. And you get to create clouds of foam dust that just love exploring the micro-caverns of your lungs. As a precaution I wore both a breathing mask and eye-goggles.
Shaping rack. I made a makeshift shaping rack with some clamps, wood, and a sheet (see below).
Shaping the nose and rails
On a piece of cardboard I drew an outline of the nose I wanted to have on my surfboard. After cutting out this piece of cardboard, I traced the outline to one half of the blank and mirrored the design on the other half. I then grabbed a saw and cut off any foam that I didn’t need.
I spent much of the time flattening the top and bottom of the board to be flush with the stringer. As the stringer was orders of magnitude harder than the foam, sanding along the interface between foam and stringer resulted in small foam ditches. It was important to have a stead hand and not to sand that area too much. What helped a bunch was to use a planer to shave the stringer down. This damaged the foam a little, so I tried to reduce the damage with masking tape. However, any damage to the foam shouldn’t be an issue as I would need to fill any holes later and fiberglass the board.
After I flattened the board, I focused on introducing nice curves into the nose. Here I used the sanding technique that tatts-Markus taught me. This involved sanding at a tangent to the curve at all times such that material is not shaved off too quickly. This technique was also important for the rails.
Shaping the the tail
I spent probably the least time on the tail and most time on the rails and nose. Using an oval object, I marked the swallow tail onto the blank and cut most of it out with a saw. I then sanded the swallow tail until it looked the way I wanted it. Here I used the technique mentioned above, which allows you to sand a perfect curve.
I was not very patient and did not always ensure that everything was perfect. In fact I made a few mistakes, such as the ditch I sanded next to the stringer at the tail (The biggest mistake was probably not having any power tools!). However, this was something I was going to deal with when I sealed the blank. I still needed to fill the holes that used to host the old fin system anyway.