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Current Replies for Mast Rake
 
  Mast Rake (c&c27dyc)
Posted: 6:52:57 pm on 8/12/2011 Modified: Never
 
Have any Mk III skippers adjusted their rake by using a shim (3/8") under the forward part of the mast? Did this improve your upwind performace? Dean.


Dean M Baldwin
Morgan "D"
Mark III - Hull 516
North Sydney, N.S.


  Re: Mast Rake (bosco)
Posted: 10:38:02 am on 8/12/2011 Modified: Never
 
Hi Dean,
  I have a Mk 111 and I put a shim of about 3/16 inch thickness under the forward edge of the mast , not to induce "rake" but to better allow the mast to bend a bit.-- I have set my forward lower shrouds somewhat tighter than the aft shrouds so that when I pull harder on the backstay adjuster, the higher tension of the fwd. lowers creates a bit of forward bend in the middle of the mast which flattens the mainsail a bit as the wind increases.
 If you want to adjust the "rake" in your rig, I suggest do it by adjusting the forestay and backstay tensions to position the mast-head behind the mast-step as much as needed to make it rake the desired amount. A heavy weight ( a pail of water?)  hung from the main halyard will let you measure the amount of rake you have.

Clare Jordan ARAGORN
  Re: Mast Rake (surfj24)
Posted: 1:42:36 pm on 8/15/2011 Modified: Never
 
I have a 1985 Mark V 27' and was wondering how to get the rake that the forum and rigging instuctions I have found recommend.  Nobody ever mentioned shimming.  I just bought the boat and it had a Baby Stay that the previous owner removed.  Well, I could not get the bend in the mast like they said I should so I rigged a new Baby Stay and that helped.  But now I know I can shim the step.  I always thought about that as being the only way to get rake in the mast but, like I said, it has never been mentioned until now when I just came accross this entry.  Thanks for the info.  What king of material did you use for the shim?

Joe Kiehm
K.I.S.S.
Hull #531
Glendale, WI.
  Re: Mast Rake (c&c27dyc)
Posted: 2:00:12 pm on 8/15/2011 Modified: Never
 
Polypropylene. Last year I cut one from lexon, this year I found these: http://www.leevalley.com/en/wood/page.aspx?p=66917&cat=1,43456
Under Lee Valley / Shims. I wanted to see if other Skips had success with 3/8"; I did. Dean


Dean M Baldwin
Morgan "D"
Mark III - Hull 516
North Sydney, N.S.


  Re: Mast Rake (surfj24)
Posted: 2:13:24 pm on 8/15/2011 Modified: Never
 
Thanks, I'm gonna take that link and see what I can get.  3/8" right?  That sounds like it would give it the proper rake they recommend.

Joe Kiehm
K.I.S.S.
Mark V Hull #531
Glendale,WI.
  Re: Mast Rake (Steve Reid)
Posted: 10:24:23 pm on 8/15/2011 Modified: Never
 
Guys:
Mast rake has nothing to do with shims especially with a deck stepped mast. It's all about how long the forestay is, the greater the measurement between the bottom pin on the forestay turnbuckle and the top pin at the masthead on the forestay. The longer the forestay the greater the mast rake, simple. Putting a shim under the toe (foreward edge) of the mast butt at the step will help induce mast bend.
One thing that you have to consider is that there were a number of mast builders for the MkV's and consequently different mast sections. I have seen at least 3 different mast sections and each one has a different bend charcteristic. Some are very bendy some are very stiff.
Mast bend has more to do with the Mainsail and how your sailmaker cut (designed) the sail. If you have a bendy mast you can have a sail that has more draft (fullness) because you can flatten the sail, for upwind work or heavy wind sailing. If you have a stiff mast you need a sail that is fairly flat to begin with because you can't bend the mast a lot to flatten it and you will have to rely more on haylard/cunningham tension to do the job.
As for the baby stay I'd be very, very carefull about using it and don't rely on it to do the job of bending the mast. The baby stay was never intended to do that, it's purpose was to stop mast pumping in heavy seas and nothing more. On the other hand if you wat to spend a lot of time fixing leaks in the deck and eventually repairing the core in the deck around the baby stay go ahead and crank on the tension.
Back to the rake issue: if you cant slack on the forestay enough to get the rake you need put a toggel or 2 under the forestay turnbuckle.

Steve Reid


Still Knot Working MkV #75
  Re: Mast Rake (surfj24)
Posted: 11:28:59 pm on 8/15/2011 Modified: Never
 
That sounds like the right combination.  I'm gonna keep it like it is for now and make the adjustments next season.  As for the Baby Stay, I like it.  It helps give bend in combo. w/the backstay tensioner and stiffens the whole rig.  I've got it at hand tight.  It's not like I've got it on a winch.  From what you described, I think I have the STIFF mast, so anything helps.  Thanks for the reply.

Joe Kiehm
K.I.S.S.
Mark V Hull# 531
Glendale, WI.
  Re: Mast Rake (Steve Reid)
Posted: 9:22:28 pm on 8/16/2011 Modified: Never
 
Joe:
Suite yorself about the Baby Stay, but just be warned it's not attached to much under the deck and has been a source of leakage on a lot of boats where the owner put tension on it. On my boat we have it on a 4:1 purchase with a snap shackle so it can be easily removed. The only time it's ever on is in large waves with heavy wind. Judging by your hull number it looks like your boat was a US Built boat and you therefore likely have the stiff mast.

Steve
  Re: Mast Rake (surfj24)
Posted: 3:23:58 pm on 8/16/2011 Modified: Never
 
Yea, that's the only time I really use it as well.  It's also on a 4/1 ratio.  My anchor point seems heavy duty on deck as well as below.  I'm pretty confident it's done right but I'll keep an eye on it as I do with everything else on my boat.  Like I said, It's only hand tight, just enough to stiffen up the rig.  I like having it as an option.  So, next season, I'm gonna lengthen the forestay and use some shims.  I'm an Arborist for a local municipality and we use them all the time.  They should work.  Thanks for all of your wealth of info.

Joe Kiehm
K.I.S.S. hull #531
Glendale, WI.
  Re: Mast Rake (clanning)
Posted: 9:01:17 pm on 8/17/2011 Modified: Never
 
Are you saying that you have success growing C&C 27 rigs in Glendale?



I'd maybe get the rig up and raked back where you like it before inserting the shims.  It seems to me that the real purpose of putting a shim under the front edge of the mast would be to 1) help transmit the compression load through to the mast step, and 2) reduce the movement caused by the mast "pivoting" on the rear edge (i.e., if the front edge is unsupported).  
Too much shim would not be a good thing, either.
Chuck Lanning
NSC, Ottawa
  Re: Mast Rake (surfj24)
Posted: 2:39:00 pm on 8/17/2011 Modified: Never
 
I'll have to feel out the rig when it's being stepped.  There's a guy that knows just about everything there is to know about everything sailing who can help me.  He's the Yard Master at the Milwaukee Community Sailing Center.  Great guy and an international Lightning, Soling, Laser etc. champion.

As far as growing rigs in the Milwaukee area, I'll tell ya, the first day I put my boat in the slip, a guy came over and told me he wants to sell his O'day and buy a bigger boat.  I told him the market is just swelling with cheap boats and he said, " NO, I want a C&C Mark V, C & C's are the best built boats out there and he won't settle for anything but."  But, he has to get thru his wife first.  Yes, We just may have started something down here.  I get a lot of looks(of course that could be because of the name---- K.I.S.S. stands for, keep it simple,stupid)  But I've got nothing but compliments on the boat.  EVERYONE says it's a GREAT boat and that I'm lucky to have one, esp. at the price I bought it for.  It's got it's little quirks, like the starboard heel, the window leakage and repair issues etc. but don't they all?  It's a sailboat....a labor of love and of course the big hole in the water we all throw money into.  Gotta love it.  I know I do.  Been at it for 30yrs and counting.

Joe Kiehm
K.I.S.S. Hull #531
Glendale, WI. (suburb of Milwaukee)
  Re: Mast Rake (clanning)
Posted: 9:21:27 pm on 8/18/2011 Modified: Never
 
Between the forum community that knows the boats and your local sailing community that has broader knowledge, you are in good hands!  Enjoy the boat!  (Yes, they all have quirks after 30 years.  I prefer to think of it as personality.)
Cheers
Chuck Lanning
NSC, Ottawa
  Re: Mast Rake (surfj24)
Posted: 1:57:07 pm on 8/18/2011 Modified: Never
 
PERSONALITY.......SPOT ON !!!