Above 5 knots
Join Date: Jun 2007
Location: East Stroudsburg, PA
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Re: Tuning The Mast
Adding very little to overbored... Every boat wants a certain amount of rake, prebend and the like as well, and that is determined by the sailmaker, and how they cut the sails for the boat.
The gauge is just so you can repeat good settings. By all means you should be doing this without the gauge if you don't have numbers to get you back where you should be.
What I usually wind up doing is, backstay tension off... (and I only have uppers, caps, and lowers).... set in column first, hand tighten to take wobble out. Set rake by loosening forestay, and adjusting mast foot. My boat likes just a little prebend, so I take up to hand tight the backstay, and adjust with caps and lowers loose, until I get just the right prebend (about 1 inch), measured with the main halyard laid against the mast... eyeball for space the tight halyard tied at the goose deviates from the mast.
Now I bring up tension to the caps, alternating making sure the mast stays in column. I look at prebend again. I try to bring tension up alternating uppers and caps until I get where I think I need to be where a bit of heel won't make my lee shrouds wobble.
The last thing I set is my lowers. I want my lowers to set so that the mast cannot bend to far forward, and pretty much nothing else.
Backstay adjustment should be run min to max to see how much bend is applied.... given that mine is a masthead rig though the actuality of backstay tension is more about forestay sag, than mast bend.
MINI MOO, a 1983 Wavelength 24 - she's a fast cow!