[C320-list] Dodger and Bimini Rub

[Pat Moriarty]

Me again......no matter what you do to the blocks, traveler or 
anything else a properly trimmed main will have the boom in the exact 
same place, because of the sail size and shape. Mid boom or end boom 
when you trim the main in fully the boom ends up in the same place. 
So the boom needs to be raised and the main needs recutting or the 
dodger lowered.

Pat #130

At 07:15 AM 1/19/2010, you wrote:
>None of the choices are very good.
>
>1.  Raising the lower blocks can't change the angle much unless you 
>raise the blocks a lot, and the shackles that you use to raise the 
>block would have to be very strong.  You also risk having a lot of 
>metal banging around during jibes.
>
>2.  Rebuilding the dodger is expensive but does not involve any 
>re-engineering of the highly loaded boom system.  You might end up 
>with not enough room to swing a winch handle on the halyard winches, 
>which is the situation on my boat.  And to the extent that you 
>change the angle to the aft block it will be by reducing the turn 
>angle at that block, which will in turn require more mainsheet load 
>for a given amount of downward force on the boom.
>
>3.  Moving the aft block on the boom has potential negative effects 
>on structural integrity:  It reduces mechanical advantage a little 
>requiring slightly more mainsheet tension.  More importantly, it 
>involves having additional holes in a very highly loaded part of the 
>boom, possibly leading to stress fractures and failure.  And by 
>moving the boom blocks closer together it will further concentrate 
>the stress on the boom, which already is pretty concentrated given 
>our mid-boom sheeting arrangement.  I would consult a rigger before 
>doing this.  I assume you will want stainless rivets, and will need 
>to take proper precautions against galvanic corrosion where these 
>are mounted in the aluminum boom.
>
>4.  A new traveller in the same location can't change things 
>much.  I wouldn't go down this route unless you are certain that the 
>traveller will be enough further forward of the existing one to 
>solve the problem.
>
>5.  Are you absolutely certain that the problem is not due to the 
>way you are sailing the boat?  You might want to post a picture 
>showing the setup of mainsheet and traveller in a situation where 
>you are having the problem.  Have you considered adjusting the 
>traveller / mainsheet / vang combination in order to see if you can 
>make the problem go away?  You might move the traveller a bit more 
>to weather or a bit less to weather and/or adjust mainsheet and vang 
>tension, for example, to change the angle of the sheet as it rises 
>to the boom.  If the sheet is essentially straight up and down when 
>the problem occurs I would try easing the sheet and moving the 
>traveller further to weather, for example.
>
>There are a lot of 320's on the Chesapeake.  I suggest you take 
>careful measurements of your boat and then find other owners to 
>compare notes. Make sure it's the boat and not the way you are 
>sailing it before you change anything.  Apologies in advance if 
>you've done this already.
>
>Scott
>
>
>Stephen Cox wrote:
>>There is a fourth option, install the new Garhauer Traveller that comes with
>>the MK II.  I have a MK II with factory dodger and there is no rubbing of
>>the main sheet blocks.
>>Stephen Cox
>>Tegwen #1141
>>
>>>-----Original Message-----
>>>
>>>Hey Everyone,
>>>
>>>I have queried the group in the past about the factory canvas on 
>>>the later model 320s (2000s w / factory canvas).  To refresh, the 
>>>main sheet is angled such that is rubs the top front of the 
>>>dodger.  The boom also rubs the top of the bimini however that is 
>>>less of the problem.
>>>
>>>I had proposed two solutions, and now have three.
>>>
>>>   1.. Move the main sheet blocks up higher (off the traveler) to 
>>> cut down the angle.
>>>   2.. Have the dodger lowered (front tube only) and have the canvas re-cut.
>>>   3.. Move the bale forward on the boom. (1 inch would probably 
>>> do it...) I went to visit APS (Annapolis Performance Sailing) and 
>>> they highly recommended against 1 and suggested 3.
>>>
>>>Has anyone moved their bale forward on their 320 and if so:
>>>
>>>   a.. Was it difficult to do if they did it themselves? (involves 
>>> drilling rivets, drilling new holes and re-riveting.)
>>>   b.. Is there any engineering concerns?
>>>I know that some Hunters are rigged the same way and have the bale 
>>>even more forward than the Cat 320.
>>>
>>>Any thoughts on this?  Thanks in advance!
>>>
>>>-Brad, Mary, Monica, and Jarod
>>>"Independence"
>>>2004 Catalina 320 Hull 1006
>>>Middle River, MD
>
>--
>Scott Thompson
>Surprise, #653

Pat Moriarty
PSI Urethanes Inc
PH: 800-888-5156  Fax: 512-837-8733
Please visit our web site at
www.psiurethanes.com