Keel Maintenance

Brad.Bates · Post by **Brad.Bates** » Sun May 06, 2007 11:24 am

Hello,

I have posted photos that relate to this subject at this URL:

http://asylum.pclc.lib.fl.us/sj24/index.html

I am renovating a San Juan 24' sailboat. The keel bolts are not all original, and the material that is on the top of the bilge between the keel nuts is deteriorating. In the past the bilge has been subjected to standing rainwater for long periods.

The photos show the top of the keel on both port and starboard, and the bilge and keel bolts. A portion of the material that is deteriorating is shown setting on the sole with one keel bolt and nut on it. That piece simply pulled loose from the rest.

The bolts that have ?heads? are replacements from some earlier repair. The rest appear to be original threaded rod that extend out of the keel.

I do not think that these bolts pass through the keel. I have not found any point where they exit the keel on the bottom or otherwise, and so I think that the original bolts were cast in the keel or turned/pressed into it when it was manufactured.

To date I have not discovered any "dead" spots in the hull, blistered hull areas, any other structural problems with the hull. However, my inspections of the overall hull have only started at this point.

My questions:

1. Should I drop the keel to repair all damage and replace the bolts?

2. If not, what are the recommended methods of replacing the bolts and restoring this critical part of the boat?

Thank you in advance,

Brad Bates

Summersdawn · Post by **Summersdawn** » Mon May 07, 2007 2:19 pm

Hi Brad,

Glad you posted on this forum. I will try to take some pictures of my bilge to show the other forum members what it originally looked like.

Group:

It appears that a previous owner, in an attempt to fix some problem, removed some athwartship stiffeners in the bilge, replaced some keel bolts with regular bolts, and added what appears to be an aluminum backing plate to the keel bolts. A little saltwater later, the aluminum backing plate/stainless steel keel bolts and water have created a mess.

I recommended this site to Brad, because as good as the San Juan group is, this is something that I don't believe anyone on that group has had experience with. I believe that some members of this forum have replaced keelbolts, dropped and rebedded keels, etc.

Good luck, Brad!

Brad.Bates · Post by **Brad.Bates** » Mon May 07, 2007 2:29 pm

Rick,

Thank you. I look forward to seeing those photos.

I have cleaned the very top of the keel from where it meets the lowest extremity of the hull (I am sure that there is a nautical term for that -- anyone out there know?) and then down a couple of inches. All of that area was covered with some form of resin that I assume was intended to prevent the hull from getting wet. Unfortunately it did not do a very good job of that. I will be posting additional photos of that soon.

Also, the rear edge of the keel a few inches from the top has deteriorated to nearly paper thin and has some holes through it at least in one spot.

The boat must have been anchored near a power plant in the past!

Brad

Summersdawn · Post by **Summersdawn** » Mon May 07, 2007 3:13 pm

The top rear edge of the keel (the part that makes the curve), is actually made of fiberglass. When I faired in my keel, I knocked it off, and created a new one. So, hopefully that means the electrolysis is only affecting the "repair".

DELETED · Post by **DELETED** » Mon May 07, 2007 7:18 pm

DELETED

Brad.Bates · Post by **Brad.Bates** » Mon May 07, 2007 10:16 pm

Tynaje,

Thanks very much for all of that. I get, of course, two types of advice on the subject of dropping the keel. Yours and similar views, and others who warn of the terrible mishaps that could come about from doing so.

I am simply too curious, adventurous, and concerned about having things done right on the boat to listen to the naysayers.

Thanks again, and I will post photos of the progress, threads, and all other details for ongoing responses and advice from you and whoever else joins in.

Brad Bates

DELETED · Post by **DELETED** » Mon May 07, 2007 10:45 pm

DELETED

Peter · Post by **Peter** » Tue May 08, 2007 1:01 am

My San Juan 24 had a problem in the same area, but nowhere near the magnitude of yours, Brad.
The keel is attached to the bottom of the hull, which is reinforced to prevent excessive sideways flex.
The port side of the hull bottom is stiffened by the dinette liner, molded into the hull.
The starboard side of the hull, adjacent to the keel, is reinforced with a double floor, consisting of the hull, balsa coring, and a top layer of resin and fiberglass cloth. This double floor extends from the mast beam back to the rear of the dinette, and from the bilge over to the galley cabinet face. The added thickness is sufficient to hold the keel reasonably rigid.

In the bilge area there is potential for water to migrate into the balsa-cored floor, due to the nature of the fiberglass work in that area. Once the floor core is saturated, the bond between layers is broken, the floor looses it's rigity, and the keel can flex sideways. This will crack the fairing on the outside of the hull.

When I bought my boat there were some minor cracks in the fairing, so I took a look at the floor in the cabin

The dark areas, right back to my foot, are saturated. After drilling some test holes through the top layer this is the mess I removed.

The floor was re-cored and glassed over, using epoxy this time, and well sealed along the edge of the bilge to prevent the problem from re-occurring.

It looks like your keel was allowed to flex for a long time, causing the cracks along the joint. My advice would be to grind off all the paint around the joint on the outside, and on the floor adjacent to the bilge inside to see what you have to deal with ... and post some more photos!
Remember, there's nothing on a boat that can't be fixed ...

DELETED · Post by **DELETED** » Tue May 08, 2007 7:37 am

DELETED

Summersdawn · Post by **Summersdawn** » Tue May 08, 2007 11:55 am

The keel on a San Juan 24 is lead. The outside of the keel joint is glassed over with tape. No cracks appear in the tape, unless the keel starts to move. I refaired my keel 12 years ago. I ground out the joint, and glassed it all back up. I used 4" stitched heavy biax tape. No cracks have appeared.

Brad, while you are doing this work, you may want to consider fairing the keel. I don't know of any templates that are available for the keel, however, I believe that it was a stock NACA foil. I believe it is an NACA 0012-64.