Tuesday, October 19, 2010

More Junk Rig Tests


I finally got out with the junk rig again.  I'd cut off the Gurney flap because I just couldn't see it being a benefit on a fast easily driven hull.  Maybe the high lift/high drag device would be of benefit to a slower heavier hull.  In any case I did max out at 10.2 knots of boat speed in a 10-15 knot wind.  
I even reefed on the way home just to see if it is as easy as advertised, and it is.  I eased the sheet, went forward and lowered the sail down two battens and it was done.  The upper sections of the sail are cut flatter than the lower sections, so you are all set for whatever the wind gods throw at you.


There is one detail that you don't want to forget when sailing any small craft.  Be sure that there is some way to prevent the mast from coming out of its step in the event of a capsize.  A partial dislodging of the mast can cause all kinds of damage to the mast collar, the hull or to the mast itself.  In the photo above I have hose-clamped a section of bamboo around the mast just below the deck and collar.  A down haul line from the boom to the deck will also do the job.  I have  done mine this way to allow the mast to still rotate.

5 comments:

Hajo said...

The people on the yahoo junkrig group that used to advocate gurney flaps don't anymore. The consensus right now is a cambered sail without one. I guess you figured that out on your own! FWIW I had a wa'apa for about 18 months with a junkrig. It was WAY overpowered at 125sf, but that didn't matter since it was so easy to reef.
It did have the gurney flap and worked fine. I guess it would have been better without.

Hajo

Gary.Dierking said...

I can't really prove that it's better without the flap unless I set up a proper experiment. For now I'd like to build another sail with more draft and lighter battens.

Dan St. Gean said...

Gary what's the sail area of your junk rig

Gary.Dierking said...

It's about 100 sq ft. The canoe could carry more, but the mast I have is probably not up to it.

sailing basics said...

Gary I think the best way to make your sailing a success is to know some basics of how to control your junk at a very primary level. You need to be very careful with those sticks especially if you weigh more.