Sail Magazine article about keel bolts
May 30, 2014 22:40:15 GMT
Post by psychotiller on May 30, 2014 22:40:15 GMT
I received the following article via email from Sail Magazine which they published given the recent events of the Cheeki Rafiki. Although it's not necessarily a revolutionary article on the subject I did find it interesting, thought I would share:
www.sailmagazine.com/boatworks/why-do-fin-keels-fail
I'm really struck by how Cheeki Rafiki was relatively new, not some 40 or 50 year old boat which had succumb to years of neglect.
Having recently went through replacing the keel bolts on my 2004 SunFast 32i I thought I would share some info that I learned while working with the boat yard. And from what I understand many Jeanneau and Beneteau keels are attached the same way. Since they use iron keels, stainless steel is not an option thus they use galvanized nuts and rods. However since they use an iron keel as opposed to lead they are able to thread the studs/rods directly into the keel which makes replacing them quite easy. But because the galvanized nuts and rods are more susceptible to rust they require a little extra attention. When researching the replacement of my bolts I even found some Beneteau guys who replaced them one by one while the boat was in the water. Not sure I'd be brave enough to ever try this but it actually seems reasonable...in theory.
One thing that really stood out for me that I learned from the boat yard when I replaced mine was that although the exposed nuts and rods may look good, you really have to look at the washers. If there is corrosion around the base of the washer then water could potentially get underneath the washer and into the threaded part of the keel. So in theory the hidden threaded part of the keel and rods could rust out and fail with very little corrosion seen above the washers. Luckily I had the opposite problem, the nuts and exposed rods looked horrible but once we backed out the rods from the keel they looked perfect. One other recommendation the boat yard gave was to put a thin layer of epoxy over the nuts and rods to protect them from water and corrosion. Attached below is a picture of an old bolt partially backed out showing the clean threads as well as a picture of a new bolts with a thin layer of epoxy. I certainly don't pretend to have any idea why the Cheeki keel failed, just trying to pass along some information I learned while working on my boat.
Attachment Deleted
www.sailmagazine.com/boatworks/why-do-fin-keels-fail
I'm really struck by how Cheeki Rafiki was relatively new, not some 40 or 50 year old boat which had succumb to years of neglect.
Having recently went through replacing the keel bolts on my 2004 SunFast 32i I thought I would share some info that I learned while working with the boat yard. And from what I understand many Jeanneau and Beneteau keels are attached the same way. Since they use iron keels, stainless steel is not an option thus they use galvanized nuts and rods. However since they use an iron keel as opposed to lead they are able to thread the studs/rods directly into the keel which makes replacing them quite easy. But because the galvanized nuts and rods are more susceptible to rust they require a little extra attention. When researching the replacement of my bolts I even found some Beneteau guys who replaced them one by one while the boat was in the water. Not sure I'd be brave enough to ever try this but it actually seems reasonable...in theory.
One thing that really stood out for me that I learned from the boat yard when I replaced mine was that although the exposed nuts and rods may look good, you really have to look at the washers. If there is corrosion around the base of the washer then water could potentially get underneath the washer and into the threaded part of the keel. So in theory the hidden threaded part of the keel and rods could rust out and fail with very little corrosion seen above the washers. Luckily I had the opposite problem, the nuts and exposed rods looked horrible but once we backed out the rods from the keel they looked perfect. One other recommendation the boat yard gave was to put a thin layer of epoxy over the nuts and rods to protect them from water and corrosion. Attached below is a picture of an old bolt partially backed out showing the clean threads as well as a picture of a new bolts with a thin layer of epoxy. I certainly don't pretend to have any idea why the Cheeki keel failed, just trying to pass along some information I learned while working on my boat.
Attachment Deleted
