SUP Plug: Step #4: rounding the rail edge

To achieve a uniform rail edge we do a few different operations.   The initial plywood bend has to be a uniform bend.  Once this is accomplished the next step is to use a router with a radius bit to cut the sharp edge off the ply.  I used a 1/2 inch radius with a bering guide.
As the fairing progresses on the side wall, we roll a palm sander over this edge.  The ply is harder than the fairing material and it slowly brings the rail side wall into conformity.
Once the rail starts to look fair, we then move to this step:  Applying fairing material with a curved spreader.
Just a cheap plastic spreader will work.

We bend it and evenly follow the rail edge with the material.  This fills in voids and gives us a skim coat to hit with additional sanding with a sponge.
The whole process takes a lot of sanding.  No way around it.