One side done!
Small very sharp stanley 101 plane does the job like buttah! I think this is a type of plastic not rubber. Rubber might have problems of it's own.
I did the calculation and the frontal area adds up to 18square inches. 72 linear inches, 1/4 " depth. so 72*.25=18. Now the air hits at an angle so this may be a bit high. Effective square inches is possibly half that.
The start and end were a little tricky. A few digs but nothing that cant be smoothed
I'm having some success with sandpaper 320 grit to smooth the plastic back. A sharp file works too but is not easy to get close to the work.
