Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 31-12-2019, 05:50   #1
Registered User

Join Date: Dec 2019
Location: Boston
Boat: Farr 50 Pilothouse
Posts: 1,348
How are wing keels constructed

I'm looking at a boat with a wing keel and I am curious how the wings are constructed. Is the whole keel, fin and wings, just a single piece of molded lead? Or is there an internal frame structure?

I have little experience with external, bolt-on lead keels. In an encapsulated keel, the strength (in regards to storage on the hard, groundings, and low-tide bumping at anchor) is in the fiberglass hull. On a normal external lead fin, I would imagine that it's pretty much all compressive strength of the lead, and it might get dented up a bit, but that's all. On a wing keel, if the wings are just molded lead, and there is some sort of upwards load that is not even across the bottom of the fin or in the center of the fin, then you have a bending moment on the wing(s). Are you just depending on the bending strength of lead at that point?

I would ideally never ground the boat or anchor in water so shallow that I risk bumping the bottom. But I just read a long thread about draft in the bahamas, and a lot of people were talking like it was inevitable and normal to run aground at times or bump at anchor.
Muaddib1116 is offline   Reply With Quote
Old 31-12-2019, 09:14   #2
Senior Cruiser
 
GordMay's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,139
Images: 241
Re: How are wing keels constructed

“Keel Construction, Design and Repair” ~ William Souter, MarsKeel Technology
http://marskeel.com/publications/MarsKeel_2016_SAMS.pdf
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 06-01-2020, 14:46   #3
Registered User
 
Nineteen's Avatar

Join Date: Apr 2015
Posts: 134
Re: How are wing keels constructed

Hi
On a Catalina the lead keel is cast as either a fin or wing.
The wing is usually heavier as the aspect ratio is lower (not as deep).
Cheers
Tom
Nineteen is offline   Reply With Quote
Old 07-01-2020, 16:23   #4
Registered User

Join Date: Aug 2016
Boat: Caliber 33
Posts: 86
Re: How are wing keels constructed

Someone at our club hit something hard this past summer with his Benneteau First (1985ish) and had a nasty surprise when he hauled out. The wing portion of the keel was detached from the rest of the keel by about 1". It seemed to be bolted on to the rest of the keel. It is iron and a little rusty, but still disconcerting.
Laskadog is offline   Reply With Quote
Old 07-01-2020, 17:26   #5
Registered User

Join Date: Nov 2011
Location: Woods Hole MA
Boat: Sabre 426
Posts: 75
Re: How are wing keels constructed

Quote:
Originally Posted by Laskadog View Post
Someone at our club hit something hard this past summer with his Benneteau First (1985ish) and had a nasty surprise when he hauled out. The wing portion of the keel was detached from the rest of the keel by about 1". It seemed to be bolted on to the rest of the keel. It is iron and a little rusty, but still disconcerting.
On a Sabre with a shallow draft the lead keel with a wing is cast as a single unit from a mold. The problem is if you go aground even in a soft bottom, it become very difficult to use reverse to escape because the wing acts like a barb and digs into the bottom. We had the misfortune of going around in a soft bottom at near low tide. Thirty minutes later the wind increased exactly at low tide and the boat fell over causing significant damage to the keel. Although it is difficult to detect, the trailing edge of the keel is warped/bent and the wing is obviously deformed. The keel weights 8500 pounds and we are waiting for its replacement to arrive.
Attached Thumbnails
Click image for larger version

Name:	IMG_2419.jpg
Views:	102
Size:	434.1 KB
ID:	206515  
__________________
SciSail
sogin is offline   Reply With Quote
Old 07-01-2020, 18:24   #6
Registered User
 
S/V Illusion's Avatar

Join Date: Oct 2007
Location: Lakewood Ranch, FLORIDA
Boat: Alden 50, Sarasota, Florida
Posts: 3,467
Re: How are wing keels constructed

If it is a boat with a iron keel, I’d pass on the boat. If however, it is lead, the wings are capable of any reasonable grounding as the keel should be one solid cast.

On our previous boat, Hunter 40.5, my friend got too close to a ledge and hit hard. At our annual haul, I saw a big chunk of one fin bent back like it a tin can looks after peeling off the top. A few whacks of persuasion with a sledge and it was back to normal. An iron keel would have been totaled.
S/V Illusion is offline   Reply With Quote
Reply

Tags
keel

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not 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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Boats over 30 feet with Swing Keels, Lift Keels, or Centerboards lays300 Monohull Sailboats 27 10-08-2023 20:12
Do Wing Keels get stuck in the Sand? JulieMac Monohull Sailboats 17 22-01-2015 05:44
Fin Keels - Skeg Hung Rudders - Full Keels bdurham Monohull Sailboats 149 26-07-2011 17:06
Sailing an assymetric spinnaker wing on wing? Will Burton General Sailing Forum 19 01-08-2006 12:10

Advertise Here


All times are GMT -7. The time now is 17:23.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.