Curved Mast

[captainseasick]

According to North's guide, the bottom 1/3 of the mast is curved by mast butt placement. (more aft, more bend).
The next 1/3 is controlled by a combination of spreader length, sweep and shroud/fore-stay tension.
The top of the sail cannot be adjusted, and will bend as main-sheet tension is applied with the mainsail hoisted, or from wind pressure on the mainsail.
Racers prefer the tapered masts, over non-tapered because they have more flex at the top.
I adjusted my non tapered mast butt to allow a tape measure, hoisted to the top of the mast, to measure 25 feet to the back of the transom as suggested by North. (This required that I move my mast butt foreward slightly) I tighten both shrouds and fore-stay until all the slack is out of them. While the boat is still on the trailer, I attach the jib halyard to the trailer winch, and crank it until the tape measure from mast head to transom reads about 25' 3 1/2" and re-adjust the fore stay. removing all slack. This puts a lot of tension on the wires (actually about 150 lbs), which is much more then I expected. This results in a nice curve in the mast which keeps the sails in the correct shape for maximum pointing with good power. It also cures fore stay sag which hurts pointing, and causes overpowering in moderate wind.
What a great design! I love these little boats, and have had a great winter and spring restoring and learning to understand them. Best of all is the fact that so many sailmakers, racers and knowledgable sailers are still very involved in this old boat, not to mention the fact that they are still in production. I have been able to learn a great deal, and mostly from this forum!
I still have yet to ever sail one of these boats, but I am almost certain that because of all the wonderful help available, I won't have to start at the bottom of the fleet when we finally get to a starting line this summer!
Mike.

[flieger]

After taking my boat to the yacht club, and having serveral seasoned skippers "kick the tires," we decided to straigten the mast.
We took it off the boat and set each end on a trailer hitches so that the mast would curve upwards. One guy sighted down the mast on one side and gave us (three/four others) instructions on where to put pressure on the mast.
So we leaned on the mast here and there and managed to straighten it almost perfectly. Many exclaimed that they were glad it wasn't their mast being bent.
It worked out great. The mast is now straight and i have one less thing to worry about.