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E32-3 keel bolt compromise?

vanilladuck

E32-3 / San Francisco
Blogs Author
WARNING: the following contains graphic images and very dirty bilge photos. Avert your browser if you have a weak constitution or the thought of your keel falling off terrifies you.

There I am cleaning the main bilge sump on my E32-3 in preparation to replace the bilge pump and I notice one bolt has some brown/black buildup of gunk on the top of the nut around the threads.

PXL_20230425_022742637.jpgPXL_20230425_023512515.jpg

So, I start scrubbin' and pickin' at it and it begins to loosen. After some Simple Green, wire brushing, and chipping with a flathead screwdriver I realize there's a GAP in the threads of the bolt...
PXL_20230425_025242996.jpg
The screwdriver head is about 5mm into the side of the bolt above. It doesn't seem to be all the way around, but mostly on one side. The other keel bolts have minimal build-up, but nothing like this one had.

Any theories about what's going on here and/or what I should do?
 

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Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
Speculation only but... I suspect that the keel has been dropped and reattached at some point. The picture looks to me like there is a lock washer under the nut, and above the large washer. I have never seen a lock washer used in this application. The torque applied to these nuts is sufficient that there is no way that any of them might ever "vibrate loose."
If the others look OK, just plan on removing and retorquing that nut, and maybe the others too, next time the boat is blocked up and resting on the keel.
Perhaps..... a prior owner had the keel re-bedded and there was some corrosion on the threads and they added an extra washer to put the nut onto an area with good threads. (?)
It's a mystery.
 
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vanilladuck

E32-3 / San Francisco
Blogs Author
I can't see completely, but I'm not sure if those are lock washers. All the keel bolts have them. What really disturbs me is the now hollow space in the side of the bolt itself (where the screwdriver is inserted). I poked a couple angled picks in there and there seems to be a fair amount of space. Almost like the bolt was sheared away... Or maybe just corroded

Is this a "drop the keel and rebed new bolts" scenario the next I'm hauled out?
 

Dave G.

1984 E30+ Ludington, MI
Firstly I would remove the nut and fully inspect the threads under it. If the threads are good below the "hollow space" that's where it really matters. If you find a lot of corrosion and missing material under the nut then you may need to come up with a remedy.
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
There are a lot of threads here about keels, internal ballast and external ballast. Many discuss re-bedding external ballast keels as boats age beyond 25 or 30 years. There is one thread that might warrant being called a 'master thread'. It is helpful, IMHO, because it shows what happens if water gets trapped between the top of the keel and the hull, and the SS bolts corrode over a long period of time.

We had our keel dropped and re-bedded due to a small leak around one bolt, and found nothing worse than some surface rust on a bolt or two.
I do remain a fan of having the keel re-bedding done every few decades, as a preventative maintenance scheme. "YMMV" as the saying goes.

If you do searches on 'keel bolts', you will find quite a bit of material.
 

Christian Williams

E381 - Los Angeles
Senior Moderator
Blogs Author
It is unlikely any 35 year old boat does not have some crevice corrosion under the nut. How much that matters depends on your confidence in the stainless bolts being suitably sized such that they are not compromised much by the corrosion.
 

Kenneth K

1985 32-3, Puget Sound
Blogs Author
ALL of my keel bolts have lock washers beneath the nuts. I believe this was Ericson's standard procedure. I've assumed the washer not only performs a "locking" function, but also acts as a spacer to keep the "corners" of the nut from cutting into the larger, flat washer (if the nut scapes the large washer, all torque settings become meaningless).

As to what to do? Goldenstate had some revealing photos from his keel drop:
IMG_1693 (1).JPG

The conservative, (or the "independently wealthy") approach would be to drop the keel and, likely, to have any damaged bolts drilled out and replaced. Like Dave G. said, I'd remove the nut and inspect the bolt further before committing to a keel drop.

The "wait and see" approach might be to just live with it, check frequently for water seepage from that bolt, and inspect the keel joint at each haulout.

The "in between" (or, the "only ask the question if you can bear the answer") approach might be to torque all your keel bolts (this is best done on-the-hard). Our 1" SS bolts are rated to 286ft-lb, but most recommend torquing to around +/- 200 lb. Torque the suspect bolt last:

- If that bolt is severely compromised, it might crack off during torquing. Or, that nut may have to be rotated significantly further than the other nuts (which might indicate stretching of a weakened bolt). But then you have your answer.

- If it holds the torque (maybe I'd only take it to 180lb) after several weeks/months of use, then it might be a reasonable assumption (lacking any other contrary evidence) that the bolt is okay.

-If, on the other hand, that bolt needs to be re-torqued after a few weeks/months, that might be an indication the bolt is corroded enough to have lost a significant degree of strength.

Also, if you have a skilled yard where you haul out, ask them their opinion and recommendations.
 
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Nick J

Sustaining Member
Moderator
Blogs Author
ALL of my keel bolts have lock washers beneath the nuts. I believe this was Ericson's standard procedure. I've assumed the washer not only performs a "locking" function, but also acts as a spacer to keep the "corners" of the nut from cutting into the larger, flat washer (if the nut scapes the large washer, all torque settings become meaningless).

As to what to do? Goldenstate had some revealing photos from his keel drop:
View attachment 46855

The conservative, (or the "independently wealthy") approach would be to drop the keel and, likely, to have any damaged bolts drilled out and replaced.

The "wait and see" approach might be to just live with it, check frequently for water seepage from that bolt, and inspect the keel joint at each haulout.

The "in between" (or, the "only ask the question of you can bear the answer") approach might be to torque all your keel bolts (this is best done on-the-hard). Our 1" SS bolts are rated to 286ft-lb, but most recommend torquing to around +/- 200 lb. Torque the suspect bolt last:

- If that bolt is severely compromised, it might crack off during torquing. Or, that nut may have to be rotated significantly further than the other nuts (which might indicate stretching of a weakened bolt). But then you have your answer.

- If it holds the torque (maybe I'd only take it to 180lb) after several weeks/months of use, then it might be a reasonable assumption (lacking any other contrary evidence) that the bolt is okay.

-If, on the other hand, that bolt needs to be re-torqued after a few weeks/months, that might be an indication the bolt is corroded enough to have lost a significant degree of strength.

Also, if you have a skilled yard where you haul out, ask them their opinion and recommendations.
I really like this approach which is why I try to avoid looking at pictures like the ones @goldenstate posted. My bolts look like @vanilladuck above. To my surprise, when I asked some of the more reputable yards in the area the all said to replace the nuts and washers and cut off the damaged sections above the nut. If it goes below the top of the nut, you only need a few threads to get full strength. I was expecting all of the yards to recommend dropping the keel and replacing the bolts. I'm definitely not independently wealthy (I doubt any of us are, we're all part of a thread dedicated to 40+ year old boats) so I'm looking for reasons not to do this job. The fact that my keel joint didn't seep any water while on the hard for a few months is my current reason for not jumping in. On the other hand, here's what my bolts look like:
20230423_130230.jpg
I'll be following along to see what other's find out despite my reasoning above to look away.
 
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G Kiba

Sustaining Member
Actually, 1X thread diameter of steel is the recommended engagement for strength. Ever wonder why nuts are the height or thickness they are?
 

Pete the Cat

Member III
It is unlikely any 35 year old boat does not have some crevice corrosion under the nut. How much that matters depends on your confidence in the stainless bolts being suitably sized such that they are not compromised much by the corrosion.

I am with Christian. I honestly have not seen keel bolts on older boats that do not have some kind of surface corrosion. I would be concerned about the place you have the screwdriver inserted. I wonder if someone had tried to ground something electrical there with another nut on top at one point---SSB? or an attempt at bonding the through hull fittings? This could cause localized electrolysis. Some boats did this kind of bonding in the 80s--Tartan and Sabre did. this. I do not like the idea of touching the nuts while the boat is in the water--you cannot pull the keel up tight by tightening them in the water. I would be inclined to wait to address this until I am in the yard and can discuss it wise old yard manager. I will also say that I am not a fan of dropping the keel as routine maintenance thing--even at 30 years. It is a major undertaking at a yard and can make things worse if not done well. While I was appalled to see the rotten keel bolt on "Sure Shot's" keel after he hit the rock--but I believe (correct me if I am mistaken) it was actually just a bolt that was used to hold the fiberglass extension in place on the aft end of the keel and was not actually a structural keel boat--may have been of some poor quality ss--and that keel did not fall off, even with a concussion that shattered some rather thick glass in that area. While keels have fallen off the mondo racers with canting keels and bulb keels on the end of a deep stick, it certainly is something almost unheard of in recreational boats. Seems like the recent interest in keel dropping is a lot like the interest in chasing "blister jobs" in the 1990s--the yards knew better, but it was good for business. Unless you hit something significant and the boat is leaking through the keel bolts, I would not touch them unless I was in the yard and had a second opinion from a very experienced yard manager. it is an unfortunate reality that finding an experienced yard manager is getting to be really difficult these days. I have a crack 2/3rds of the length of my keel at this time, according to my diver. No leaks--bilge is dry, so I am sailing the heck out of the boat on SF Bay and will tend to it when I get to the yard for a bottom job in a year or two. Oh, and my bolts have rust that looks much like yours. I hope I am not tempting the fates by sharing this with everyone.
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
I hope I do not come across as overly cavalier about re-bedding a keel. Our one larger local yard that does this kinda routinely has a big welded up steel "cradle" to lower the boat and keel onto, with their travel lift. They use big wood wedges to fine tune the fit of the keel. Then inside nuts are removed and the travel lift lifts the boat up, so the bolts, keel top, and hull can be inspected and cleaned up for new sealant.
Back in the 90's I dimly recall this adding about 2K to my yard bill. It was more than a bottom paint application, but it did not seem out of line on a 50K valued boat.
It occurs to me that a lesser skilled or experienced yard might not want to do it or might charge a lot of $ to -in effect-use your boat to learn on. :(
The local yard that did this for me also builds ocean racing boats on a custom basis, so they probably have more background in boat construction, too.
Truly, "YMMV".... :rolleyes:
 
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Nick J

Sustaining Member
Moderator
Blogs Author
@vanilladuck, might be a random question, but did your boat happen to have the original battery charger installed? That's how mine came to me and it was boiling the batteries. The previous owner's mechanic kept replacing batteries instead of looking at the charger. I'm wondering if the battery acid may have had a hand in accelerating the corrosion of the bolts. It Did a number on the plywood floor of the battery compartment

20200328_110514.jpg
 

Nick J

Sustaining Member
Moderator
Blogs Author
Here's a good reference thread for repairing the keel bolts and rebedding the keel:

 

bigd14

Contributing Partner
Blogs Author
My keel bolt washers were horribly rusted and corroded. I worried about this for a long time and finally just replaced the washers and nuts and tightened them down and tried not to think about it.:oops:
 

Prairie Schooner

Jeff & Donna, E35-3 purchased 7/21
Bryan, can you see the nature of the cavity? Could it have been done intentionally, as Ray speculates? It seems such an odd place for there to be that much corrosion. Is it possible a PO tried to shorten the bolt to make room for something, and bailed on the attempt?
p.s. Thanks for the trigger warning, btw.
 

Pete the Cat

Member III
Here's a good reference thread for repairing the keel bolts and rebedding the keel:

I just read this whole thread and I am not sure what I took from it. Seems like there has never been any known keel failure of an Ericson (I think I heard of some recreational cruising boat somewhere, but it seems impossibly rare in my 45 years of sailing and reading). I take little from seeing a keel "smile", or even a crack in a hull to keel seam. Layers of bottom paint will faign a crack that I have seen dumb surveyors raise alarms about in our yard--the yard guys just shake their heads.. As I have mentioned before, good surveyors are getting as hard to find as decent yard managers (there are fewer folks who have done enough of the actual yard work themselves to make an informed judgement). I am generally unimpressed by cracks unless they show some disturbing of the laminate, and this will take some grinding to assess. When I surveyed my Ericson for purchase it looked beautiful in the slings--but she was a marina queen before me and never went anywhere. My guess is the first time I sailed her in 25 knots that keel crack "showed up' in the layers of bottom paint. But I will grind it back at next haulout.
Seems like some folks have leaks, and that a small number of those that can eventually be traced to keel bolts. Seems like a confirmed leaking keel bolt would be a signal to investigate a crack further--or even if you had no crack, I would be looking for a lingering, sizable wet spot at the keel joint after hauling the boat. Keel bolts leaking is a matter of serious concern, but most often the leak is elsewhere and just collects there.
Also, in the reference is that the quality and experience of a yard I would trust to drop the keel; I have worked in 5 yards. Two of them I would definitely not let near my keel. There is a story in the thread about welding extensions on the bolts--I am no welder, but have seen incredible corrosion in SS welding when slightly different welding alloys are used. I would be skeptical of some fix that has not been reviewed and supervised by someone familiar with metal boat construction and repair. First do no harm. I have seen new keel bolts installed. I think it is lucky most folks do not need more than one replaced because a true fix can be incredibly technically difficult and expensive.
I think if you hit something at hull speed and stopped dead, you need to haul or dive the boat immediately. I hit a rock at 7+ kts with my Tartan and developed a very slight leak--not from any of the keel bolts. I had the boat hauled and their was a crack where you would expect: at the aft end of the keel (as well as a chunk of the leading edge of the keel missing).. The very experienced yard owner recommended that we put the boat back in the water and that I finish the cruising season--which I did because the leak was about a cup a day.. The boat was pulled in the Fall and the keel dropped over the winter. The keel bolts were fine on this 40 year old Tartan 37, but the hull was indeed cracked and some floor stringers were severed from the hull (No TAFG) so the furniture and floor had to come out. Disassembling the interior and rebuilding of the frames was the most expensive part, but the bill was $25k--I am not sure what the dropping the keel would have been alone, but the yard said it did not come off easily--and these are very experienced boat folks.
After reading the thread, my belief is that you still need some indication there is a problem before dropping a keel.
And that you are going to need some significant expertise and second opinions from folks who know lots more than me.
Just an opinion. Others will think differently.
 

goldenstate

Sustaining Member
Blogs Author
My sense is:

Do many (most) 30+ year old sailing yachts have undiagnosed keel bolt corrosion?

Yes.

Does the presence of corrosion suggest a catastrophic failure (the keel falling off) is imminent?

Not even a little bit. No.

Does corrosion eventually lead to leaking/seepage around the keel bolts?

Meh. Maybe? I mean you would know if it was really a saltwater leak that could be explained in no other way.

Is proactive keel removal and re-bedding appropriate for a $1k per linear foot boat when market labor rates are $137 per hour and crane time is $400 per hour?

No way. Go sail the boat, to Tahiti if you like.

Keep in mind that if you take the keel off and find a problem, the repair will involve many hours of work, over which you will have no control.

I suspect old hoses and cantankerous, breakable sea-cocks present much greater catastrophic risk potential to boat health and well-being.

 

G Kiba

Sustaining Member
You would know Tom! Great answer. Hope Bryan can finds some solace in your reply cause I think you are right on the money (pun somewhat intended).
 

Frank Langer

1984 Ericson 30+, Nanaimo, BC
I'm not so sure on this one...mmm...
Tom is right about the many things that can cause a crisis while sailing--seacocks, hoses, broken shroud/dismasting, missing clevis or cotter pin, electrical fire, propane explosion, broken rudder and more. I often sympathize with the coast guard who have to respond to these situations.
I think as responsible sailors and for good seamanship one should anticipate potential problems and take all reasonable(!) steps to avoid them. This will vary depending on the anticipated sailing conditions, skills and abilities of crew aboard, cost, etc. For example, I replaced the 18 year old forestay inside my roller furler to avoid it breaking due to chafe inside the furler extrusions, which could result in the mast falling into the cockpit--especially troublesome if I have my wife, kids or grandkids aboard. The rigger said it could likely have lasted another three to five years, but for a total cost of $650 (Canadian), the resulting peace of mind was worth it.
When I start to feel a bit bored on a light wind day, I'll often entertain myself by pondering what I would do if a given part failed suddenly, preparing myself in case it ever does happen. This has helped me solve two significant problems/crises quickly over the years.
Just some food for thought....
Frank
 

Christian Williams

E381 - Los Angeles
Senior Moderator
Blogs Author
I think the most useful factor is likelihood. Shrouds fail often, rudders bust, engines let us down, bad judgement puts us in a pickle.

But fin keels just don't fall off cruising boats, which have low aspect keels and plenty of bolts spreading the load. As Ray says, we have no record of a keel falling off an Ericson, even when damage is severe. After hurricanes the beaches are littered with sailboats--keels still attached despite very rough treatment.

It's just observation, yes, but so is the second law of thermodynamics based on observation, not theory, and so maybe our natural concern about keels falling off can be tempered by probability.
 
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