O'Day 25 lost mast - SailNet Community
 
LinkBack Thread Tools
post #1 of 2 Old 04-05-2010 Thread Starter
Senior Member
 
davidpm's Avatar
 
Join Date: Oct 2007
Location: Madison
Posts: 4,202
Thanks: 284
Thanked 68 Times in 59 Posts
Rep Power: 9
 
O'Day 25 lost mast

I'm helping a young man with his new boat a 1972 O'Day 25 that was dis-masted. Remarkably the only visible damage so far is:
1. Bent furling foil
2. Slight bend in mast step
3. Starboard chain plate pulled out.
4. Standing rigging has some kinks I don't like in it.

I'm pretty sure I'm telling him the right things but just to check.
The chain plate is a very small piece of stainless about 3/16 by 1.25 by 14" bolted to a 1/2" bulkhead tabbed to the hull and screwed to the headliner.

The plywood rotted of course and the chain plate pulled out dropping the rig.
Replacing the whole 1/2 bulkhead is probably more than he is willing to do what with the tabbing and such. I suspect that if his dad, with access to a machine shop, just made a much larger chain plate that would to down another foot to get into solid bulkhead we could just fit in a new piece of word for cosmetic purposes. I'm pretty sure it would be stronger that original.

I was thinking about sistering the bulkhead but then just a big enough piece of steel should be even stronger. Yes?
davidpm is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of 2 Old 04-05-2010
Telstar 28
 
sailingdog's Avatar
 
Join Date: Mar 2006
Location: New England
Posts: 43,290
Thanks: 0
Thanked 17 Times in 13 Posts
Rep Power: 15
         
The problem with that idea is that the bulkhead is important in supporting the hull and cabin in resisting torsional loads as well as supporting the cabintop against both compressive and tension forces. If the bulkhead is rotted to that degree, then the entire integrity of the hull and cabintop is compromised IMHO.

The mast step pushes down on the cabintop in the center—the bulkhead may well be the part that transfers the loads from the cabintop down to the hull and keelson. If it is rotted, the addition of a larger chainplate does nothing to solve this problem.

The chainplates pull up and in on the bulkhead and if the bulkhead is rotted, the way the inward and upward forces are transferred to the hull will cause point loads that would be lessened were the bulkhead intact to spread the loads over a greater area of the cabintop.

Sistering the bulkhead is almost as much work as replacing it properly, and changes the alignment of the loads and where they are transferred.

Finally, as the loads generated by sailing cause the boat to twist, the bulkhead connects the cabintop to the hull and prevents any real movement of one in relation to the other. If the bulkhead is rotted, then there is nothing to help tie the two parts together and the cabintop may shift or warp under higher loads.

Sailingdog

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.

Last edited by sailingdog; 04-05-2010 at 11:02 PM.
sailingdog is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Deck vs. Keel Stepped Masts Envirella Gear & Maintenance 10 11-29-2009 11:06 AM
Deck stepped Mast-Always Bad ? Mrs Mutiny Boat Review and Purchase Forum 24 10-05-2009 07:55 PM
which 38ft boat? bluewaterdreamer Boat Review and Purchase Forum 10 10-03-2007 12:54 PM
30ft Catalina BigRuss Boat Review and Purchase Forum 3 09-09-2006 05:33 PM
Is one better than the other? gandydancer Gear & Maintenance 7 07-11-2002 06:08 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome