Mast Rake

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Bill

According to the log, our recently acquired 1984 Irwin 34 has had all standing gear replaced several times over the years. Recently I was able to determine that the mast head is raked at least 15" aft of its base and there is a very slight depression just aft of the mast base where the mast is stepped. It appears that each rigging job has resulted in an ever increasing aft rake of the mast. Weather helm in gusts is impressive and at times the boat will not respond to the helm until the gust passes. I'm guessing that may be caused by too much aft center of effort caused by the mast's rake. I'm hoping someone out there can tell me how much rake (if any) is normal for our boat. Thanks for you help,
 
Jun 13, 2005
559
Irwin Barefoot 37 CC Sloop Port Orchard WA
Weather helm is normal

I don't know the 34 in particular, but 15 " does not seem excessive. There should always be something so that the headstay is tighter than the backstay. I have 18" on a 26' racing sloop I own. The question should be about how much weather helm you have in a moderate steady breeze. If it's ok then your rake is OK. The gust is affecting you because you are fighting it. When you see a guest coming you should turn upwind as it hits to work the boat to weather, spill a little air, and prevent the increased heel. Your heel angle should probably never exceed 15 degrees. The increased heel you get by not playing the puff may be causing your roundup, because it moves the center of effort to leeward to produce a force called a weather couple. If you don't want to play the puffs with the helm, do it by spilling some air from the main by easing the traveller down, twisting the main off with the mainsheet, or reefing. So check your helm in moderate to light steady wind. Your rudder angle shouldn't be much more than 5 to 10 degrees with the sails properly trimmed. Good luck--- Joe Shirley
 
Jan 9, 2005
4
- - Corpus Christi
thanks

Joseph, thanks for the great suggestions. I have had some success easing the traveller and reefing always helps but I have not tried turning into gusts. I'll sure give that a go before I start messing around with the mast's rake angle. Now I have to go read up on "weather couple" :eek: Thanks again for your response. Bill
 
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