... and Gary too. On Sep 27, 2008, at 9:51 PM, James Poulakis wrote:
> Jerry, Howard, Doug Gordon, & Chad: > > Thanks for the insight. I just checked Spirit's rudder. The > trailing edge is cleanly squared off and about 1/4 inch wide for most > of its length. The rudder is about six months old and in very good > (but not perfect) condition. A careful sanding that brings the edge > down to 1/8" (per Jerry's recommendation) and a few coats of varnish > sound like good line items for the Winter Project List. > > As reference for anyone else looking into this phenomena : Spirit > was constructed in 2008 and her bottom has not been sanded, nor > painted with anti-fouling. She has the standard rudder with the > "turned down" rudder rod that Jerry described, and the rod appears to > be chrome plated bronze. > > Jim > M17 "Spirit" > > On Sep 27, 2008, at 1:19 PM, Howard Audsley wrote: > >> To clarify, that should be a sharp trailing edge, just as Jerry >> points >> out, the edges are not rounded. The quote was from the book. I took >> that to mean the side of the rudder near the trailing edge, not the >> edge itself. The bottom paint thing stands. >> >> Howard >> >> >> On Sep 27, 2008, at 9:47 AM, Howard Audsley wrote: >> >>> First I'd heard of this was in "Royce's SAILING ILLUSTRATED, >>> Volume 1", >>> bottom of page 134. >>> >>> "The trailing edge of the wide rudder at force 3 vibrated >>> considerably, >>> which eased when it was rounded. We had a similar vibration which >>> disappeared after the edges were sanded. When new bottom paint is >>> added, our rudder will vibrate for approximately a month, then >>> stop". >>> >>> I have noticed the same thing with new bottom paint. If you think >>> about >>> it, the vibration is likely caused by a harmonic of some subtle >>> cause >>> of unbalanced lift on one side, which breaks down at some point, >>> allowing the flow to force the rudder back to it's trailing aspect, >>> lift is generated again, etc. >>> >>> Inspect your blade and/or run your hand over the trailing edges to >>> see >>> if you can see or feel any subtle bumps in the varnish or edge. If >>> you >>> find one, sand it smooth. Look at it under low light conditions, >>> shining a flashlight down the edge. Shadows will appear if it's not >>> perfectly smooth. >>> >>> They do not all do it. >>> >>> Howard >>> >>> >>> On Sep 27, 2008, at 2:20 AM, James Poulakis wrote: >>> >>>> Sailing even with a moderate breeze makes Spirit's rudder hum loud >>>> enough to drown out the Pillar Point fog horn. The rudder is new >>>> and >>>> doesn't seem to be warped. Is there a trick to stop this or is it >>>> just a Monty thing? >>>> >>>> Jim Poulakis >>>> "Spirit" (M17) >>>> >>>> _______________________________________________ >>>> http://mailman.xmission.com/cgi-bin/mailman/listinfo/ >>>> montgomery_boats >>>> >>> >>> >>> _______________________________________________ >>> http://mailman.xmission.com/cgi-bin/mailman/listinfo/ >>> montgomery_boats >>> >> >> >> _______________________________________________ >> http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats > > > _______________________________________________ > http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats
