1984 Hunter 31 keel joint

PGIJon · Oct 6, 2014

Hi Nathan

You may want to check out the thread that I created earlier regarding my keel.

http://forums.hunter.sailboatowners.com/showthread.php?t=162681&highlight=v

-Jon

bobbyfingers2001 · Oct 6, 2014

First thing I would do is check all of the keel bolts in the bilge areas, paying particular attention to any sunken or spongy areas.

On the outside I would scrape away any soft areas as these are useless anyway, this would reveal what is going on in between the keel to hull joint.

What I am seeing is most likely a failure of the joint seal which probably was the result of a hard grounding and subsequently lead to the fracturing of the fairing, which thus led to water intrusion into the fiberglass at the keel to hull mating area. The holes where the keel bolts go through the hull were either never sealed prior to the keel being installed or the keel had worked its way loose over time allowing water to get into the fiberglass. This being the case the keel will need to be removed, the top surface will need to be cleaned off and checked to make sure it is smooth, flat and square, and that the bolts are still serviceable.

Do a thorough inspection inside the bilge areas to the front and back as well as both sides of the keel area looking for any spider cracks as these will require attention during the repair process.

The bottom of the hull will need to be left to dry. Depending on the moisture content this can take anywhere from a few weeks to a few months or more, then any areas that had osmosis or soft spots would need to be completely and properly repaired by grinding the entire area until you reach clean dry solid fiberglass. This will need to be done on the inside of the bilge area as well. Then these areas will need to re-glassed properly on both sides. The bottom would need to be finished to a very high degree of accuracy as any waviness or out of plumb or square will cause the keel to be misaligned and can cause the hull to fracture when the keel bolts are tightened.

Once the fiberglass repairs are made and the keel is ready for installation the mating surfaces need to be sealed properly; if this is an older boat and you don't expect to have to remove the keel again I would use 5200, unless it is a newer boat (which I am assuming it is not due to this problem) Either way the bolts will need to be torqued down and checked after a day or two to check for any crushing or squeezing (if the bolts require more than 1/8 turn I would be concerned that the job was not done properly. If the bolts torque properly I would remove them one at a time and put a liberal amount of Loctite on them and re-torque one last time.

Next the hull and keel will need to be glassed-in and re-faired and painted.

Then its party time!

Probably not what you wanted to hear, but I hope it helps.

Nathan said:
Hello!

This is my first post on this forum, wich i've been looking at for a few days now. Very recently my parents have taken possession of a nice hunter 31, a nice upgrade from the DS-20 we had a long time ago..

Today was the end of season haulout, and i noticed the famous keel joint issue of this perticular boat. Now, i would just like some advice on how bad/normal it seems, and what would be the best course of action to fix, or at least, keep the boat from degrading.

It appeared that at certain areas along the joint, the filler/paint used was very soft, like wet silicone/paint.. (boat was out of the water since maybe 1 hour)

What would be the best approach? strip all sealer and grind, paint, seal, paint? I still got some research to do!!

Oh yes and by the way, is it normal that the coating (antifouling?) seems to be missing in some areas of the hull, as seen in my pictures?

Thanks alot!!

Dan Johnson · Oct 7, 2014

Nathan...

From your pix, it may seem like it's cracked all the way around, but I think what you are seeing is edge rust of the steel keel at the seam with the 'glass hull. This is a common issue with the H31/H34 series with steel instead of lead keels.

Unless the keel bolts are actually loose, which you will find out shortly with the boat's weight sitting on blocking under the keel on the hard, your chore will be to clean out that joint and seal it up with an epoxy or some other filling, then fair it over before painting.

Steve Dion · Oct 7, 2014

I would agree that this may have been made worse because of a grounding. Rust is a common problem on any boat with a cast iron keel. It can be treated to minimize the rust (check the archives).

You may want to have a marine yard take a look at this for their opinion once you are on the hard for an opinion.