Jim, More good information. It sounds as if your boom is now only 3/4" longer than Jerry's 7'9", but that small amount might be key to avoiding trouble. If my main wears out, I too will have the new one cut shorter, because it is already a little too long for an outhaul. While fiddling with the mainsail position, I also noticed that the leech of the sail near the top rubs the backstay pretty hard on every tack, particularly if I have the boom above 19". I wonder if that much roach is necessary for adequate speed. Like you, I seem to find plenty of wind in our mountain lakes, to the extent that I often leave one reef in for days to cope with the big gusts. Tom M17 Scintilla On May 29, 2012, at 9:18 AM, James Poulakis wrote:
Tom, Spirit is hull #648. The boom extrusion without the end hardware was 8'-1/4" long. The main is stock Elliot Pattison. With the boom at 18" from the deck (per Bob Eeg's instructions), and the mast raked aft as far as the forestay turnbuckle would allow, the boom could get hung up on the backstay in heavy winds and the roach would snag up in light winds.
My solution was to cut 2-1/2 inches off the end of the boom. I would have cut it down to Jerry's recommended 7'9", but that wouldn't have been long enough for the foot/outhaul and I didn't want to get into mainsail surgery.
I haven't had the boom hang up since, but it did give the backstay a whack during a sloppy jibe. Of course altering the boom had no effect on the sail roach which still gets stuck in light winds. When the day comes for a new mainsail I plan to cut the boom down to the proper length and have the main cut to fit. No need for maximum sail area in San Francisco Bay.
Jim M17 Spirit
On May 24, 2012, at 3:32 PM, Tom Jenkins wrote:
Hi all,
I have a 2004 Montgomery 17 with an 8' boom, which can hang on the backstay in a wild jibe. I consequently tend to run the boom 17" up the mast rather than the 28" that sends the main to the tippy-top. I would be most obliged if someone out there with a similar boat would tell be how high he/she runs the boom, and if a vang keeps the boom from kissing the backstay. It seems logical, but my logic does not always prevail. I am mounting a vang anyway, but I need to know how high to ride the boom so I can figure where to mount the bail for the vang. Thanks ever so much; I would rather be sailing than punching experimental holes in my spars.
Tom Jenkins M17 Scintilla