Glassing in Hull/Keel Joint

[SailingFan]

Originally Posted by reed1v

That is a cast iron fin keel, not a lead keel. Secondly, the keel is actually separating from the hull. Its a structural issue and does require dropping the keel to see what is going on. I suspect the boat hit something real hard, either while sailing, or in storage. If you have bought this boat, my condolences.
BTW, its got nothing to do with zinc anodes. Time to call in a boatyard repair person to look at it. Personally looks bad to me.

The erosion I spoke of was not in the picture, it is at the trailing edge of this fin. Note it is not rust, just lead that is "not there" when it should be, up near the hull. The absence of this material creates a little of a wiggly appearance of the trailing edge, though I suppose I could file it to even the contour... There is no rust on this keel fin, only dull grey or shiny silver where I scuffed it. It is lead.

I do think your are right about the structural issue, though. I did see some rust on the front bolt pair, and am considering tapping a couple more into this keel through the bilge slot (there is little bilge area in the Hunter 27 of this vintage, danged little), using a method I saw elsewhere in these threads to replace the current bolts.

[replusted]

Originally Posted by reed1v

Never seen a lead fin keel. Usually the metal is too soft to hold together unless encapsulated. Usually lead is used in the "bulb" portion with the support shaft made of cast.

Are you seriously saying that you have never seen a lead fin keel that wasn't encapsulated? You need to take a walk around any boatyard in the off season when boats are out of the water and look at some keels. You'll be amazed at how many are lead. Actually lead is preferred over cast iron because it is able to absorb the shock of a hard grounding better than cast iron.

[reed1v]

Originally Posted by replusted

Are you seriously saying that you have never seen a lead fin keel that wasn't encapsulated? You need to take a walk around any boatyard in the off season when boats are out of the water and look at some keels. You'll be amazed at how many are lead. Actually lead is preferred over cast iron because it is able to absorb the shock of a hard grounding better than cast iron.

Evidently you read more than you experience. Full keels with lead shoes, yes; narrow fins, no. If he has an all lead fin keel, that could be part of his problem since a lead flange would have a low level of structural integrity. Or have you never worked with lead?

A grounding with cast iron will dent and deform the keel. A grounding with a lead shoe will do the same, only more so. A grounding with a full keel of lead probably would rip the fin apart. Lead is soft which is why you do not see many boats made of lead where there use to be many boats made of cast iron with rivets.

[reed1v]

Should point out that Hunter switched to cast iron back in the 80s. Before then their "lead" keels were a mix of metals. Pure lead has a very low tensile strength(about 1000 psi). Do not know what they may have mixed in with their lead to form the old keels. No one would make a fin out of just lead. If you got a flat out racer that is not going to be kept long, then pure lead fine. If you are going to produce a cruising boat that is suppose to hold up for several decades, then a lead fin is not the way to go( as witnessed by most if not all the current boat builders using cast iron).

[Sandero]

An attached deep fin keel is a cantilever and it's quite stiff. The hull would likely be stiff but not as much. If you had simply faired the connection... it's almost certain that a crack at the joint would occur. unless there is perfect mating of the top of the keel to the buttom of the hull (there wont't be).. water will enter the "joint" and find its way to the bolts. So... keels are bedded with caulking to prevent water from getting at the keel bolts... which may corrode... but a small amount of corrosion may not compromise their strength. It would depend.

[Jim Cate]

Originally Posted by reed1v

Evidently you read more than you experience. Full keels with lead shoes, yes; narrow fins, no. If he has an all lead fin keel, that could be part of his problem since a lead flange would have a low level of structural integrity. Or have you never worked with lead?

A grounding with cast iron will dent and deform the keel. A grounding with a lead shoe will do the same, only more so. A grounding with a full keel of lead probably would rip the fin apart. Lead is soft which is why you do not see many boats made of lead where there use to be many boats made of cast iron with rivets.

Reed, in this case you are just wrong, for there are thousands of production boats with lead fin keels. I've owned two myself, a yankee 30 and a palmer Johnson Standfast 36. both had bolt on lead fin keels. Typical practice is to use one or two percent Antimony in the lead to improve structural characteristics, but to me, that qualifies as a "lead" keel.

If those are too esoteric for you, consider that all the thousands of Catalina yachts with fixed keels use lead fins... and there are many other builders who do as well.

Criticizing the experience level of the previous poster seems a bit awkward in light of this knowledge...

Jim

[SailingFan]

All I know is that the only surfaces of the keel that are visible now all the paint is gone are made of lead. If there is something alloyed in (most likely it is!), it is still a lead keel. There is NO rust on the keel surface. None. There IS, however, some rust on the keel bolts at the leading edge in the bilge, which may be from below or may be from the packing in the shaft log dripping a little over the last nearly 40 years. Either way, the crack is there, and it is not as large as what the photo makes it seem as I was zoomed in. Additionally, the trailing edge has corroded away (but not rusted), and the prop shaft has several small pits in it that I am considering options for filling. As I am going to have to investigate the keel bolts further to learn more, I suppose for now my question is answered, and for that I thank everyone who replied to my intrusion into this thread. It is quite appreciated, and I hope I did not rerail anything in this process for the OP. I have another thread in the Maintenance section for my outhall, but did not see replies to it yet. I have photos documenting issues as they arise, so if anyone is interested in what a nearly 40 year old Hunter may look like, you can see it there. I welcome any comments or observations that arise in any case, and thank you all heartily!

[replusted]

Originally Posted by reed1v

Should point out that Hunter switched to cast iron back in the 80s.

True, Hunter did switch from lead keels to cast iron but not because cast iron was a better material for that application. It was a cost saving decision because the price of lead was eating into corporate profits. The thousands of boats built by C&C, Tartan and many other builders use lead fin keels. I had a C&C 29 and after 33 years it was still structurally sound. (and no rust either) A small percentage of antimony is added to the lead to give it additional strength. And to answer your question ReedIv, I am very familiar with the characteristics of lead. I poured my own wing keel for a previous boat. It was made of lead. I can't believe that you think all current boat manufacturers only use cast iron for their fin keels. Go to some of the upcoming boat shows at look at the keels, it's going to be an enlightening experience.

[Sailmonkey]

Originally Posted by reed1v

Never seen a lead fin keel. Usually the metal is too soft to hold together unless encapsulated. Usually lead is used in the "bulb" portion with the support shaft made of cast.

Come on man!!! Never seen a lead keel? First you insist on hanging "kettles" on your rode, now this!!!

There is a big world of knowledge out there that you seem to have closed your eyes to.


Sent from my iPhone using Cruisers Sailing Forum

[SailingFan]

"Kettles?" Maybe meant "Kedges?" Never heard of kettles hung on anchor rode.... It was probably a mental typo, I do that now and then. Of course, I am rather new to sailing, so...

It is all good!

[Jim Cate]

Originally Posted by SailingFan

"Kettles?" Maybe meant "Kedges?" Never heard of kettles hung on anchor rode.... It was probably a mental typo, I do that now and then. Of course, I am rather new to sailing, so...

It is all good!

SF, the term that he has corrupted is "kellet". It refers to a heavy weight that is hung from some mid point in an anchor rode, hoping to improve the angle of the rode as it reaches the anchor. Most theoretical studies have concluded that it does not help very much,yet some folks swear by them.

Jim

[Don C L]

Ok so I conducted my own very scientific analysis of the local boatyard and storage lot's collection of bolt-on keels... and there are a lot of keel/hull joints (more than half... ok not so scientific) that are either glass covered or just really well faired in and showing no joint. I didn't want to be rude and go banging or chipping on anyone's keel but I did come across one gentleman who had recently put a layer of glass over his "Catalina Smile" to make it look better, stronger and to prevent water from getting in there. I didn't query him much but I am skeptical that the one glass layer will prevent the water ingress for too long or add any real strength to the joint. It did look better though. One boat that is interesting is the Yankee 26 with a keel stub that has a longer (deeper) section forward. I was able to see that because the keel joint was visible of course. Seems a good idea to me that kind of dog-leg in the stub to make it all stronger. I wonder if the Yankee 30 had the same thing, Jim? There must be other boats built that way, maybe other S&S, I just haven't seen them.

[minaret]

Originally Posted by Don C L

Ok so I conducted my own very scientific analysis of the local boatyard and storage lot's collection of bolt-on keels... and there are a lot of keel/hull joints (more than half... ok not so scientific) that are either glass covered or just really well faired in and showing no joint. I didn't want to be rude and go banging or chipping on anyone's keel but I did come across one gentleman who had recently put a layer of glass over his "Catalina Smile" to make it look better, stronger and to prevent water from getting in there. I didn't query him much but I am skeptical that the one glass layer will prevent the water ingress for too long or add any real strength to the joint. It did look better though. One boat that is interesting is the Yankee 26 with a keel stub that has a longer (deeper) section forward. I was able to see that because the keel joint was visible of course. Seems a good idea to me that kind of dog-leg in the stub to make it all stronger. I wonder if the Yankee 30 had the same thing, Jim? There must be other boats built that way, maybe other S&S, I just haven't seen them.

My much larger S&S design has a dog leg in its massive stub. It's ridiculously strong! Having some vertical faying surface in the joint makes a huge difference in many ways.

[Don C L]

Originally Posted by minaret

My much larger S&S design has a dog leg in its massive stub. It's ridiculously strong! Having some vertical faying surface in the joint makes a huge difference in many ways.

Makes one wonder why all keel stubs aren't built that way....?

[Jim Cate]

I wonder if the Yankee 30 had the same thing, Jim?

I'm embarrassed to admit that I don't remember! I kinda think it did, but not sure... but then I sold that boat over thirty years ago.

Jim