Need tuning help

[charrette]

i have a 1988 hunter 35 which is the same as the later 35.5 that was produced from 1990 to 1994. i tuned it myself this past season after viewing brion's video. the boat in the video is an early 90's 37.5 but the rig is the same (fractional rig with aftswept spreaders and a back stay which is a cross between a standard fractional and a b&r rig). before you set your prebend you should check your sail luff curve. the manual for these boats indicates 1" of prebend in the mast. if you don't tell your sail maker what prebend you want they most likely will default to 1". in brion's video he sets the prebend to about one mast depth which is consistent with other publications on tuning a fractional rig with aftswept spreaders. in any case the prebend should match the sail luff curve. too much pre-bend beyond the sails luff curve will flatten and depower the sail and vice versa if there is not enough. it is a good idea to have a backstay adjuster with this rig and take advantage of mast bend and how it effects sail shape. i am in the process of rigging one on my boat now.

one other note- the upper shrouds should be fairly tight with this rig about 20% to 25% to keep the headstay tight. with the backstay tensioned the uppers should be at about 20% and with the backstay loose the uppers will be close to 25%. they should not exceed 25%. snelden has a rig tuning guide that can be downloaded which is a good resource for various rig types as well as the book 'illustrated sail and rig tuning' by ivar dedkam.