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Leaking keel on a Hunter 31

Jan 7, 2020
12
Hunter 31 Belmont Bay Marina, Woodbridge
I have a 1981 Hunter 31. In the summer of 2019 we had the steel keel sanded and three layers of epoxy applied. The bottom was then painted. Everything looked good. Yesterday we pulled her out of the water to fix a stuck seacock and I found a weeping spot on the keel. There is one on each side, but the port side is much more pronounced. Anyone know what this is before I dive into another expensive repair?
 
Jan 7, 2020
12
Hunter 31 Belmont Bay Marina, Woodbridge
Sorry, I hit send before loading photos. The spot is in the center of the keel and 2/3 of the way up the keel. The first photo is the port side. The second is starboard.
 

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Jan 19, 2010
9,435
Hunter 26 Charleston
I do t see any rust so I’m guessing your keel is lead. That is a positive. You said three layers of epoxy... I’m going to guess that is osmosis and you got the beginnings of the pox. Looks like you caught it early so not hard to fix.
 
Jun 8, 2004
8,560
-na -NA Anywhere USA
My understanding that is a cast iron keel. Lead keels came later. Mars Metals in Canada cast the keels. There should be a hull fiberglass stub which the keel is attached to. 5200 is the manufacturers sealant used. Is anything seeping into the bulge at the keel bolts?
 
May 27, 2004
1,619
Hunter 30_74-83 Ponce Inlet FL
My 1979 H30C came with a lead keel. I think all the early Hunters did.
 
Jan 7, 2020
12
Hunter 31 Belmont Bay Marina, Woodbridge
Thanks for the comments. It is a solid steel keel. There is no obvious water at the keel bolts.
 
Jan 24, 2017
523
Hunter 34 Red Bank NJ
looks like from your photo that you may have water intrusion from a blister possibly caused by electrolysis.
 
Jun 4, 2004
389
Hunter 31 and 25 and fomerly 23.5 Stockton State Park Marina; MO
Your boat has an iron keel. There is a sump molded into the keel. On my 1985 Hunter 31 there is at least one bolt hole in the sump that Hunter doesn't use. I discovered this while doing the false bilge mods (described on this site) and I drilled too far..... right through the hull. When I removed the plugs I had cut out I discovered the hole which was already threaded and corroded from previous water intrusion. The bottom of the hull sump does not fit tight to the keel sump so they just fill the keel sump with a pile of plexem before assembly. This apparently after time does not stop water movement across the top of the keel, as evidenced by the reddish-black stains and corrosion on the keel and bolt hole, and the water that I now have seeping into the sump.

Is it possible that you had water in that hidden hole that froze when the boat was out of the water for a winter lay-up? Is the keel actually cracked then or just water getting behind the paint? Things to investigate.IMG_2747.jpgIMG_2749.jpg
 
Jan 7, 2020
12
Hunter 31 Belmont Bay Marina, Woodbridge
Thanks! Since my initial posting, which was taken the day after it came out of the water (nothing frozen), there are now multiple areas that look like calcium deposits on the hull. They are on both sides of the hull. They are not wet, but have a dark edge and a white chalky center.
 
Jan 7, 2020
12
Hunter 31 Belmont Bay Marina, Woodbridge
looks like from your photo that you may have water intrusion from a blister possibly caused by electrolysis.
That makes sense. What is the solution? Grind the spot down, epoxy and bottom paint?
 
Jan 19, 2010
9,435
Hunter 26 Charleston
That makes sense. What is the solution? Grind the spot down, epoxy and bottom paint?
So that is what I thought I said in post #3. Sorry for using Jargon. Blisters are (the pox) what can happens to some layups if the formula is a little off. Water soluble materials get trapped on the backside of the fiberglass cloth and this creates osmosis... which puts pressure inside the cloth and lifts it off in a blister.
 
Jan 24, 2017
523
Hunter 34 Red Bank NJ
grind all loose material and paint, clean with solvent, prime and apply epoxy, then repaint
Good as new. Not a big deal if you don’t neglect it.

I would also check out your zinc anode and maybe lower a portable zinc anode to a stainless steel cable and clip it to a keel bolt when the boat is at your dock. I’ve had to do this due to my marina has a bad electrolysis issues that I believe is from other boats near by. Whenever I don’t clip I zinc to my keel bolts my shaft zinc is almost gone by fall hauling.

hope this helps
 
Jan 7, 2020
12
Hunter 31 Belmont Bay Marina, Woodbridge
Thanks! I had asked the Marina to add zincs to the keel and they acted like I was crazy. Can I just mount anodes on the hull?
 
Jan 24, 2017
523
Hunter 34 Red Bank NJ
no,
The hull is fiberglass therefore will offer no protection against galvanic action. Zincs are for the protection of anything metal submerged in water. In order to protect the keel they have to be mechanically connected in some form. I’ve seen people drill into the back edge of the keel and bolt them on there. I don’t recommend doing that because that will defeat the reason why you had the keel sealed with epoxy.


my solution is:
I buy a clamp on grouper anode from west marine , then cut off the end of the cable with the clamp at the end.
Cut the clamp end off approximately one foot from the end. Strip off approximately four inches of the shielding from both ends. Then attach a length of stainless steel cable of the same diameter to reach your keel bolt and be able to hang over the side of the boat so that is roughly thee feet below the water. Then attach the two ends of cable to each other using stainless steel hose clamps then wrap with electrical tape. I don’t crimp the ends so that I can replace the zinc as needed.


I think this may be the best way to protect against galvanic action along with zincs on the prop shaft. Your boat is essentially the same as mine just smaller version. I’ve been doing this for thirty years now with no issues

hope this helps