i fixed a beat up old singlefin, and the glassed on fin was pretty beat up as well, so i sanded the really rough parts down, then used resin to create a bead, and attempt to reform it. there is MAJOR humming coming from the fin, and id like to at least lessen, if not totally remove the vibrations/humming/cavitation/whatever you wanna call it. any pointers as to how i should shape it, etc? i would post pictures… but my digicam is in the shop.
I havent had that problem for a long time, but when I had fin hum I used to file the trailing edge a bit sharper. That seemed to help a lot.
ck the leading edge, especialy down by the base for flat or odd shaped spots? refoil. make sure trailing edge dosen’t have any flat spots? refoil. also ck for resin drips along the edge of the fin or anywhere else. This should stop the humming . Have a great surf ! http://www.edgefins.kauaistyle.com
Old single fins sometimes have a leash hole drilled in the fin - get rid of it!An excessively thick tip of the fin with poor blend into the rest of the fin can cause problems too.