I also spray on a hydrophobic waterproofing compound after sanding. Its supposed to make the surface 100% waterproof and also protects from light scratching.
It is good idea for bottom surface. But I have doubts about the top one. Water should stick to it to create lift. Otherwise it may cause flow separation. Sure vacuum will try to prevent the separation. But still ...
That video you link from the Levitaz guy is the only one that says to sand the pressure side (which I call flat side). Everybody else (Armstrong, Alex Aguera of Gofoil, Fanatic, and others) say to sand the curved side. Which is kind of shocking, really. In my experience, I successfully tuned to silence a bunch of Armstrong wings by sanding the curved side. I failed to silence Axis wings that way though. Cheers.
To some extend, just by making the trailing edge thiner makes a noticeable difference, Funny indeed different brands recommend to sand different sides.
@@mikkgodfree3886 It's was clearly noticeable right after sanding it, now I can't even tell what's the difference :). More slippery/glidy for sure and it makes way less noise now.
