Keel seam weeping

J

jubilee

.
May 8, 2014
1
Hunter 460 Kemah,Texas
I have a 460 thats been hauled and there is weeping through the keel joint, still not dried after 4 or 5 days. I have been told I have to drop the keel and re-seal etc. Is this really necessary? Can I clean the seam 5200 and re-torques the keel nuts, there is not really very much water that accumulates in the bilge. Also is it true that I have to drop the mast if the keel is removed?
Thanks for any input, by the way this is a 2001 model, if that means anything more.
 
Terry Cox

Terry Cox

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Dec 25, 2000
5,932
Hunter Passage 42 Shelter Bay, WA
There should be no weeping through the keel stub joint. Something caused the joint seal to become compromised. The only sure way to fix it is to drop the keel, clean the stub joint and re-bed with 3M5200. Ours was weeping and I had the yard do this procedure in 2004. It has remained sealed ever since after thousands of cruising miles. The yard can tell you whether they have to drop the mast to do the repair.

Some will tell you that you can fix it by applying sealant on the outside of the joint. Perhaps. But something broke the seal and that needs to be looked at from the inside. Covering it with fresh sealant merely covers up the broken stub joint seal.

Not sure about the H460, but our 1991 P42 keel SS stud bolts are molded into the lead keel. Short of melting down the keel, no way to remove them, according to the yard.
 
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C

Capt jgw

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Feb 8, 2014
1,300
Columbia 36 Muskegon
If there's sea water in the joint, the bolts may be suffering from crevice corrosion. They can rust to nothing in the joint and still look fine in the bilge. The only way to know is to pull the bolts. You may be able to do this without dropping the keel, but that won't address the leak which is causing the problem. You're going to have to drop the keel. It's really not that bad a job. I would not leave the mast up without the keel attached. One good wind storm and she'll tip over.
 
shemandr

shemandr

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Jan 1, 2006
7,585
Slickcraft 26 Sailfish
I don't think any competent shipyard with insurance will be keen on leaving the rig up while dropping the keel. It wasn't an option for me. Given the value of your boat I think you have to do this. The alternative is a problem selling the boat, when you may have to be on the hook for a more expensive repair. For a competent yard removing the keel isn't a big deal and if your yard is freaking out about it you should take the boat somewhere where it is routine. When I had this done I think the yard had the rig down, the keel blocked and the keel off in a day - maybe a few hours - I wasn't there. It was a couple thousand dollar deal if I remember. Removing the keel wasn't the most expensive part. Fiberglass work etc. which was necessary for my situation was much more. Simply resealing shouldn't be that bad.
But the big question is why did the seal break down?
 
JamesG161

JamesG161

SBO Weather and Forecasting Forum Jim & John
Feb 14, 2014
7,770
Hunter 430 Waveland, MS
Capt jgw said:
If there's sea water in the joint, the bolts may be suffering from crevice corrosion. They can rust to nothing in the joint and still look fine in the bilge.
Click to expand
Stress Crack Corrosion SCC happens when the bolts are under stress ( keel bolts YES), there is Chlorides present (sea water YES), high temperature (not really so very slow corrosion), lack of Dissolved Oxygen (maybe if seeping until space between hull and keel is full and stagnate),

AND....
The wrong Stainless Steel grade used for the bolts, not proper for this service!

If, as a competent boat designer (Hunter is one ), you pick the right grade of Stainless you will have NO SCC problems even if the seal is broken (happens to the best flexible hull boats using Fiberglas®.)

In an ideal world a stress corrosion cracking control strategy will start operating at the design stage, and will focus on the selection of material, the limitation of stress and the control of the environment. The skill of the engineer then lies in selecting the strategy that delivers the required performance at minimum cost.

I would call Hunter and insist on finding out which grade of SS they used. I would have used Alloy 20 SS.
It would be cheaper to have a reputable laboratory to "scrape sample" your bolts to find if a proper SS was used. Then no guessing or unneeded keel drops for peace of mind.

On this link, you can see a list of SS grades that have no SCC in boiling brine solutions.
http://www.ssina.com/corrosion/stress-corrosion-cracking.html

If you do find competent Hunter response, ask them to publish which SS they used for all of their boats.
Jim...

PS: I would guess, but it is not my boat, that you have properly designed bolt SS grade.
 
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