Keel Bolt Questions

[Dave, 397]

As I march ever-steadily towards ending up with the LeComte Medalist, a number of questions/curiosities continue to arise.

So, here's one.

I have no experience at all in dealing with an externally-fitted ballast shoe (such as the original design Triton had) and thus seek the sage of this group.

First of all, the pig at this point is bare lead. I wondered what, if any, special measures are needed to prepare the surface for antifouling paint. Also, the hull has been barrier-coated in the past, but the barrier coat was not applied to the ballast shoe. Any thoughts on why this might have been done as it was?

Now it gets good. Present owner, a Wood Sailboat Guy, suggested that it would be prudent due to the boat's age and my intended usage to have the keel bolts x-rayed. Anyone know about this, whether this is a real good idea or an excess, etc?

Last...the specs I have obtained for the boat describe the keel bolts as being of Everdur *or* Stainless Steel. I'm presuming Everdur must be similar to Monel or Inconel, but would love to know the answer and/or how to identify one from the other while hanging upside down in the water tank.

Well, I guess that was 2nd to last. Here's the last: If there is a problem with one or more keel bolts, I am assuming that the ballast shoe has to come off to remedy it. I think I have a reasonable picture of what might be required to remove the shoe, but no idea at all how one actually replaces the bolts. Are they threaded into the lead, or is this one of those nightmarish jobs with no good end?

Thanks,
Dave
(Hoping to be) Medalist #67

[Tim]

Dave,

You can coat the bare lead with underwater metal primer, or zinc chromate (I think), but I have not found it particularly necessary. I just paint directly over it, and have had no problems with adhesion. Remember to freshly grind the lead just before you coat it, though, as the lead oxidizes very rapidly and anything other than clean metal will provide less than perfect adhesion as a substrate. There's no need to epoxy or barrier coat over the lead--why waste the product on a surface that will not form hydrolysis or osmotic activity?

Check the seam between lead and fiberglass. If it's uniform and tight, there's probably little to worry about. There will almost always be a visible seam, but unless there are obvious gaps or signs of stress, the keel bolts are probably still doing their job.

Everdur is a type of bronze alloy, with very long life in these sorts of conditions. Lacking any external forces that may have changed things, these fasteners should outlive the boat. I know of no easy way to determine whether the current keel bolts are cast into the lead or threaded--both methods are used. If the bolt heads are exposed in the bilge, you can try unthreading them. It will either work or it won't. Worst-case, if you need to to feel better, you can install some new bolts while leaving the old right in place. Your ballast keel is plenty wide and long enough to allow enough room for this. You cannot remove bolts that are cast into the lead. Only experimentation, or, if you're lucky, Medalist-owner support, will allow you to determine whether the bolts are cast or threaded. It should, however, be pretty clear whether they are stainless steel or Everdur. One never knows, though.

Otherwise, you can leave it as is, or you can remove all the nuts and lift the boat slightly off the ballast (as Bruce, here on the forum, did on his Tripp Javelin).

Personally, I am more of a believer in the "no sign of trouble=no cause for immediate worry" school when it comes to keel bolts. Keel bolt failures are rare, rare, rare. The type of ballast/hull connection on boats like the Triton, or the Medalist, or other full-keel boats, is inherently los-stressed because of the wide, long, low-aspect nature of the ballast and the space for plenty of bolts and bonding surface. Modern fin-keel boats have hull-keel joints that are under much, much higher stress, which is far more likely to cause problems over time. I know of absolutely no documented cases of full keel-type ballast or bolts experiencing catastrophic failure, though of course there are many documented failures of fin keel bolts.

How many bolts are there? The more there are, the less you need to worry, I think. It would be typical to see 4 or 5 sets of two bolts on a keel like that. With that many bolts, you could theoritically lose several and not have to worry about the ballast falling off. It all comes down to your own peace of mind, however, and to what extent you need to go to satisfy yourself. Everyone has their own breaking point on this sort of thing. As a routine-type replacement or maintenance situation, though, the keel bolts should probably be low on your list, just based on how long they historically last.

[JetStream]

I would second Tim's comments. Having just reinstalled the 4000 pounds of external lead on Jet Stream, I would offer the following:

I think the Medalist 33 built in 1962 (also designed by Bill Tripp) was probably built in the same fashion (if not by the same yard) as my Javelin. The Javelin's keel bolts are stainless and I found them to be in excellent condition. I did rebed the keel with 5200 as opposed to the high density urethane foam (I think) that was original. I was more interested in keeping water out of the joint to prevent future laminate degradation than I was worried about keel bolt failure. When I do the epoxy barrier coat, I will include the lead just to make future bottom painting easier. Don Casey recommends wire brushing the lead/wet epoxy so that any oxidation that occurs after you clean the lead will get encapsulated.

[catamount]

I am looking at a 25-year old boat with a lead fin keel bolted on with stainless steel bolts. I didn't count but there are probably about ten 3/4" bolts holding the 5000-lb keel on the boat. Inside the boat, the bolts and nuts appear to be in great condition, and they certainly don't "sound" punky. The washers are well-bedded with polysulfide inside the boat, so leaks at the joint don't show up inside the boat. Outside, there is a small amount of rust that weeped from the small crack at the keel-to-hull joint on the starboard side. The crack is probably within the realm of what would be considered normal for a bolted-on fin keel. When the current owner bought the boat in 1986, his survey report indicated the same problem on the port side, and called for re-bedding of the keel bolts, which apparently was done.

Obvioiusly, since then the joint has opened up enough to allow seawater into the bolts again, which have corroded some more to produce the rust. So how worried should I be about the integrity of the keel bolts? Could I sail this boat from the Chesapeake up to New England before undertaking further work?

If I brought the boat home, what would be the best course of action: (1) caulk the joint from the outside and forget about it; or (2) drop the keel to inspect the bolts and re-bed the whole joint?

Presumably these are "J" bolts cast into the lead, but since lead and stainless shrink differently, should I be worried about corrosion of the bolts down in the keel, and not just at the joint?

If I do drop the keel to inspect and rebed and the bolts look scary, then I guess I could sister them. Or should I just go ahead and sister them anyways?

If the decision is to drop the keel, how do I do that with the boat on blocks and jackstands in my backyard? Do I jack up the hull rest of the boat (~5000 lbs), or do I lower the (5000 lb) keel on jacks? Or do I hire a crane to come by for 1/2 a day?

Thanks,

[Tim]

Without actually seeing the keel, it sounds to me as if you're describing a perfectly normal circumstance. Most external lead fins tend to open up the seam at the hull end over time. Depending on how wide this opening gets, it may indicate a need to retighten keel bolts--or possibly to partially drop the keel for rebedding before tightening.

You've seen how stainless steel will bleed rust under most circumstances, such as fasteners or hardware on deck. I would not offhand be concerned about the slight rust stains you see coming from the seam--again, this is pretty typical, and probably is indicative of surface rust on the bolts, rather than a sign of more serious corrosion.

In the end, however, much depends on what is required for you to feel comfortable with the situation. I don't have enough information to determine whether you should be worried or not, but my instinct is that there is nothing unusual going on. If you feel uncomfortable without dropping the fin for inspection, then by all means you should do so. Personally, keel bolts are the last thing on my mind in most cases, barring any serious external signs of damage or looseness (which I do occasionally see).

Keel bolts do fail on occasion, but rarely--and then most often in highly-stressed racing fins. With so many bolts in place, it would take a complete failure of several, or even most, of them before your keel would be at risk. It sounds, based on the information you provided, as if you would be very safe in continuing to use the boat as is. If no leakage is entering the bilge through the bolt holes, then it is unlikely you have any significant movement going on.

Probably dropping an external fin every so often is a prudent idea, after 25 years, but is not necessary either in most cases. Keel bolts do seem to last extremely well.

I hope this reassures you, but if you have other information to provide (photos?), I might be able to tell you more.

[catamount]

Thanks, TIm. Your comments do help re-assure me. I hear so much about "crevice corrosion" of stainless steel, particularly for parts that are isolated from interaction with the oxygenated atmosphere (such as keel bolts), that I do worry a bit. Assuming there are no surprises in the survey, once I get the boat home (eventually) I probably will try to lift the hull off the keel a bit so I can take a look and rebed the joint with a surplus of 5200 (as per a previous discussion in another thread somewhere on this forum).

Regards,

[Rachel]

Hi Catamount,

I don't have anything useful to add here, but, being a boat-nut, I'm just curious what kind of boat you're looking at :-)

--- Rachel

[catamount]

The boat in question is a 1980 Peterson 34 offshore racing sloop, hull #82 out of a run of 92 that were built to a Doug Peterson design between 1976 and 1981 by Composite Technologies Inc., dba Island Yachts, in Texas.

This will make the fourth "project" sailboat in our yard...

Regards,

[Tim]

Given the boat's racing pedigree, and the likelihood that she has been sailed hard with the rigging under great tension, I am not at all surprised at your keel crack.

With this history, some known issues with Peterson 34s, and the age of the boat, I think eventual dropping of the keel would be prudent. However, I would still guess that the situation is static enough to launch and use the boat in the short term, at least.

This will make the fourth "project" sailboat in our yard...

Gee, I only have two project sailboats, and one project powerboat. I guess I'd better start looking again! hehe

Glad to see someone else shares this affliction so energetically.

[catamount]

Tim, I guess maybe you're not counting Glissando?

In my case, I'm counting:

1) Laser #811 (circa 1990 project)

2) San Juan 21 #555 Quasar (ongoing project since 1999)

3) Lightning #12945 just acquired this spring

and now

4) Peterson 34 #82 (you got to open the door when opportunity knocks, right?)

See http://sailing.thorpeallen.net/ for full details.

You might notice an approximate order of magnitude increase in discplacement at each step from the Laser to the (average of the SJ21 and Lightning) to the Peterson 34....

Regarding the issues with Peterson 34s, the one I'm looking at has some wet and delaminated deck core (pretty standard); potentially bad rudder bearings; and of course cosmetics, as well as my concern about the keel bolts and lots of small niggly things that need attention. The engine, the original Yanmar 2QM15, which looks pretty rough on the outside, is an unknown until the survey and sea trial, but is said to start and run well enough. The hull and all the bulkheads, tabbing, stringers, floors, etc, all appear to be in good shape. The mast and standing rig were replaced about 10 years ago.

The plan is to keep the boat in the water at my father-in-law's dock in Annapolis for the next year (the boat is currently in Oxford, MD), and then to sail it up to New England next summer, and finally have it trucked from Kittery(?) to my house in Keene to begin overhauling it. All assuming there are no big surprises in the survey.

[Tim]

Tim, I guess maybe you're not counting Glissando?

That's correct: I consider her to be "complete" at this point, and not still a project.