# Keel saga, for those contemplating this procedure for your boat...



## CharlieCobra (May 23, 2006)

Classic brain fart... While working on clearing out the bedding material on the keel yesterday, I managed to forget about the laws of torque and gravity, getting my sawsall blade stuck in the process. 

The keel joint has about a 1/4 inch of epoxy around the outside edge of the 5200 bead (yes, 5200) from an apparent attempt at sealing this keel before. Of course, I have to clear all of that out to separate the two. So here I am, happily cutting along while taking care to avoid the keel bolts hidden in the mess, when suddenly, the blade jams and turns to a pretzel.

With judicious use of my multitool, wedges and a mallet, I was finally able to extricate the blade without harming the boat. Needless to say, the customer doesn't get charged for the 1.5 hours I spent getting it out. He didn't forget to use wedges.....

Pictures later today. I'll be nice and keep everything in this one thread for you folks.


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## sailingdog (Mar 19, 2006)

LOL... ain't physics a *****.  Good to hear you and the boat are okay... Sawzall blades are relatively inexpensive and if that is all it cost you, you got off pretty lightly.


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## CharlieCobra (May 23, 2006)

Phase one of the CS-36M keel rebed is done. Other than having to spend $300 for tools (read as giant sockets and breaker bars) and having a 3/4" breaker bar shatter on one of the bolts (replaced for free), it went well. All of my prep work at separating was worth it as the hull came off in one clean easy lift to be set aside.










and










Chris took a video but had to go to work so I won't have it until tomorrow. Once the keel was separated, they set the hull on stands to the side with the load still on the crane while we cleaned up the mating surface. We applied packing tape to the hull for a mold release and applied epoxy and microballons (like peanut butta) to the top of the keel. They then picked the boat again and set her on the keel nice and slowly. I was too busy working to take pics.

After the hull was back on the keel with about 6,000 Lbs still on the crane, the boys tightened the keel bolt to draw her down. They then eased off and we torqued to 100 Lbs for now. I went around swiping off the excess (and there was a lot of it) and faired the joint as it oozed out.










and










So, she'll sit and cure overnight and then we'll lift her off again in the morning to apply 4200. Once that's done liberally, we'll reset her the last time and torque the keel bolts to full torque.

Then it's on to the rest of the job....


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## olson34 (Oct 13, 2000)

I take it the bolt threads were in good shape?

Would you mind sharing with us the final torque you put on those bolts?

(I had a yard drop and rebed our keel several years ago, and am curious about the exact # of foot pounds)

Cheers,
L


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## Maine Sail (Jan 6, 2003)

Charlie,

One trick I learned, or actually created, when I did my keel re-set was to rout a v-shaped groove about 1/4" in from the outer edge of the keel around the entire perimeter. 

The idea is that when you "butter match" the keel to the hull you will have minimal sealant thickness as the two surfaces are now mirrors of each other. 

When the keel & hull flexes, as they do, this thin sealant layer may not have enough thickness to accommodate the movement. By Dremeling a v-groove you have just created a thick gasket spot, like beveling a drilled hole in a deck. This gasket can accommodate significantly more movement than 1/64th of an inch of sealant. 

This groove will be outside the bolts and lap the perimeter of the mating surface of the keel. It takes al, of about about ten minutes to do once the keel is dropped and it does not need to be very deep, perhaps 1/8" deep at the most.

Trying to let the sealant cure some to "create a gasket" normally does not work or works to well, cures for too long, and you now can't get the keel tight enough to not induce movement because of the "gasket". 

Alternatively you can slightly chamfer the edges of the keel bolt holes on the underside of the hull to create a little more o-ring there. A laminate trimmer and a 45 bearing guide bit works well for this but don't go very deep, just a touch off the edge is all you need. Doing this and the above trick will probably guarantee a dry keel stub for a very, very long time.


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## CharlieCobra (May 23, 2006)

The bolt holes in the hull are already chamfered and there's plenty of room for the sealant to fill them, plugging ingress of water.


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## CharlieCobra (May 23, 2006)

olson34 said:


> I take it the bolt threads were in good shape?
> 
> Would you mind sharing with us the final torque you put on those bolts?
> 
> ...


This boat has one inch 316 SS bolts and the final torque on those will be 190 ft lbs.


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## GaryHLucas (Mar 24, 2008)

I am curious where the 190 ft lb number came from? If the bolts are 1"-8 and assuming say 50% efficiency of the thread the clamping load would be about 18,000 lb per bolt.  For a 1"-14 and 50% it would be about 32,000 lbs. So how large are the washers, and are they thick enough to take that kind of load without bending? If the bend the load on the center portion increases dramatically. How much compressive load can fiberglass take long term? Maybe 5000 Psi? So that suggests washers with a surface area of 3-1/2 to 6-1/2 square inches for these bolts. When the boat heels over how much tension is applied to the the bolts, and additional compression to the washers?

The reason for my curiosity is that when the keel nearly fell off my Hunter 27 in the early 80s I found the washers bent and the fiberglass under the washers completely pulverized.

Is it possible that the bolts are large in diameter to take bending loads, and should be torqued to a rather low value to avoid crushing the fiberglass?

About 10 years ago I attended the Atlantic City, NJ sailboat show and was sitting on board a J boat. I commented to the salesman that I was impressed with the chainplates on a 32 foot boat that were fastened with 6 3/4" bolts! He replied that the bolts were large for surface area, so they don't tear through the fiberglass bulkheads, and that they had Nylok nutd lightly torqued so as not to crush the bulkhead. I thought wow what a knowledgeable salesman! Then I looked at his name badge. Duh, it was Rod Johnstone, the boat's designer!

Gary H. Lucas


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## CharlieCobra (May 23, 2006)

One way to find out, ask the designer Tony Castro. The washers are 8" wide by 4" long and one inch thick.


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## olson34 (Oct 13, 2000)

Hi Charlie,
Thanks a lot for your input on this forum. I have linked your info back to some keel rebedding forums over at the ericson site (with disclaimers...)
 

It is great to have real-world input from ship wrights.

Best,

the old Olson guy


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## blt2ski (May 5, 2005)

Charlie,

I would assume then that the 190 lb spec is from original specs? hence the ask the portuguese. or should I say born in, now an englishman designer, Mr Castro.

David made comment wed eve after the local race, his and my boat are very similar, but his is on steroids!

Marty


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## CharlieCobra (May 23, 2006)

This is Tony's reply:

Dear Charlie



Good question..... I remember once doing this calculation and being surprised to find it was not enough.!! I We never were able to explain why. I guess the materials of the keel and a typical GRP bottom is not exactly a homogeneous, really solid substance so there is more “sponginess” than a calculation can predict, so tightening keel bolts has always been a question of ”feel”.... I know this is not very technical !!!!! I only remember doing this myself once and I used a 12” spanner and tightened as hard as I could, but I have seen race boats being tightened with much longer levers.....

If I had to do this today I would try to ask someone that normally does this job ...

Regards

Tony Castro


I went with my gut AFTER we torqued the big bolts to 150 Lbs.


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## GaryHLucas (Mar 24, 2008)

CharlieCobra said:


> One way to find out, ask the designer Tony Castro. The washers are 8" wide by 4" long and one inch thick.


Charlie,
That sounds like very adequate size and thickness! Someone clearly thought it through. I'm currently working on my third boat with keel problems related to entirely to poor design, so I am always interested in seeing how other boats are put together.

Thanks,

Gary H. Lucas


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## CharlieCobra (May 23, 2006)

After not having access to the crane yesterday, we got it this morning and pulled the hull off. The homemade mold release of packing tape worked pretty well but didn't wanna come off the hull without some diligent scraping. Once we got separation, they hung the boat off to the side while I did some last minute fairing.










After fairing the epoxy edges even with the keel top, I took to cleaning the bolt threads.



















After which, we all jumped in with caulking guns to apply the 4200. Big circular mounds were laid up at the base of the bolts and more was applied by hand up the bolts to where it had been before.










Once this was done, we set her back on the keel, holding some weight while the boys tightened bolts. After they were manually tight, we let off weight and repeated with 100 Lbs of torque. Then we came off all of the weight and the final torque settings were applied. While the torqueing was going on, I was busy getting 4200 all over me while I shaved the excess off with a spreader.

So, the keel is done and now it's on to bottom paint and a compound/wax job. I don't have the parts for the water heater R&R yet so hopefully, that's next week. We have a hard date of the 23rd.

BTW, I still haven't gotten my videos but will this weekend.


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## casey1999 (Oct 18, 2010)

For the stainless steel keel bolts/nuts in the bilge, do you incapsulate them to keep any bilge water from causing crevice corrosion?


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## mitiempo (Sep 19, 2008)

Best to leave them exposed and try to keep the bilge dry. Encapsulating them will cause crevice corrosion if there ia any moisture present - and there is sure to be, regardless of how dry you try to keep the bilge.


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## casey1999 (Oct 18, 2010)

mitiempo said:


> Best to leave them exposed and try to keep the bilge dry. Encapsulating them will cause crevice corrosion if there ia any moisture present - and there is sure to be, regardless of how dry you try to keep the bilge.


Would the use of say silicone bronze or monel be a better material for keel bolts?


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## CharlieCobra (May 23, 2006)

That's what older boats used to good effect.


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## mitiempo (Sep 19, 2008)

Lead keel - stainless, bronze, or monel (hard to find and pricey)

Iron keel - stainless or mild steel


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## CharlieCobra (May 23, 2006)

Yep, if using an iron keel, the last thing ya want is to set up galavanic corrosion by using disimilar metals within the keel.


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## sailhog (Dec 11, 2006)

Nice work, Charlie. Last winter I did some keel/hull joint work on my Catalina 30, but didn't drop the keel. I excavated a bunch of 5200 from the joint and ground out the glass around the circumference of the keel. I used biaxel (cloth on one side, roving on the other) and West Systems to seal her back up. The leading edge of the keel was overlapped with the biaxel and the WS fared. It's still not a structural fix, but the keel stub is now sealed and far sounder than she used to be. Sure looks better....

Anyway, that's some fine work you're doing!


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## CharlieCobra (May 23, 2006)

Thanks Hog, ya oughta see what I'm up to this year...


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## casey1999 (Oct 18, 2010)

CharlieCobra said:


> That's what older boats used to good effect.


Why do many lead keel boats over the last 30 years seem to use Stainless for keel boats? Seems that silicone bronze would be much better choice.


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## sailhog (Dec 11, 2006)

Casey,
That's a good question. I suspect the 31 year old stainless keel bolts on my boat are experiencing some significant crevice corrosion. I just try to put it out of my mind when I'm way out there, and so far the strategy has worked for me. 

I'm not too up on the matter, but wouldn't bronze have its own issues, being softer?


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## mitiempo (Sep 19, 2008)

Bronze is softer but roughly the same strength as stainless. It is not subject to the same crevice corrosion that stainless is. When you look in the bilge and see the shiny stainless it does not tell if there is crevice corrosion - it is the buried part of the stud that is the problem. The stud shown below looked fine based on the portion visible in the bilge - only when dropping the keel was the corrosion evident.


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## casey1999 (Oct 18, 2010)

So if I ever need to replace the keel bolts (for an all lead keel), would bronze be the way to go?


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## mitiempo (Sep 19, 2008)

If the keel is lead it is not that easy. The bolts are usually `J`shaped and are cast into the keel. The only way to remove them is by melting the lead. Mars Keels in Ontario Canada has a service that does this but the keel has to be shipped to them. MarsKeel Technology Keel Bolt Replacement


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## casey1999 (Oct 18, 2010)

mitiempo said:


> If the keel is lead it is not that easy. The bolts are `J`shaped and are cast into the keel. The only way to remove them is by melting the lead. Mars Keels in Ontario Canada has a service that does this but the keel has to be shipped to them. MarsKeel Technology Keel Bolt Replacement


My keel is lead but has "windows" in the keel to allow access to the nut in the keel. The windows are filled with a filler that would be dug out, exposing the nuts of the keel bolts. Remove the nuts and extract the keel bolt form inside the boat. Therefore keel bolt could be a all thread (bronze) or a rod threaded on each end to accept the nuts. Still a big job but doable. I think my stainless keel bolts are ok for now, but who knows- really hard to tell. Maybe one day change to bronze.


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## L124C (Oct 4, 2007)

*Yikes!*



mitiempo said:


> Bronze is softer but roughly the same strength as stainless. It is not subject to the same crevice corrosion that stainless is. When you look in the bilge and see the shiny stainless it does not tell if there is crevice corrosion - it is the buried part of the stud that is the problem. The stud shown below looked fine based on the portion visible in the bilge - only when dropping the keel was the corrosion evident.


Did any of the other bolts have that kind of corrosion? Why was the keel removed (was flexing evident, etc.)?


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## mitiempo (Sep 19, 2008)

It wasn't my keel. I believe Maine Sail posted it in a thread about a year ago. I think there were several corroded like the pic shows. It is a good example of what can happen in the part of the bolts you can't see.


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## L124C (Oct 4, 2007)

*Good thread. Thanks!*



CharlieCobra said:


> Once the keel was separated, they set the hull on stands to the side with the load still on the crane while we cleaned up the mating surface. We applied packing tape to the hull for a mold release and applied epoxy and microballons (like peanut butta) to the top of the keel. They then picked the boat again and set her on the keel nice and slowly. I was too busy working to take pics.
> After the hull was back on the keel with about 6,000 Lbs still on the crane, the boys tightened the keel bolt to draw her down. They then eased off and we torqued to 100 Lbs for now. I went around swiping off the excess (and there was a lot of it) and faired the joint as it oozed out.


Why was applying epoxy to the top of the keel necessary (I'm assuming this was the primary reason for dropping the keel)?
Was the assumption made that because no corrosion was seen on the exposed section of the bolts, the concealed sections were sound?


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## mitiempo (Sep 19, 2008)

In many cases the hull and top of the keel are not a good match, and the builder packs in sealant to fill the gap. The proper way is as posted by Charlie. It makes the top of the keel a close to perfect match to the hull. 

I remember reading years ago that at Hinckley it took days to mate a keel to the hull as the high spots in the lead were planed, fit checked again, etc. Few builders take this kind of care (and expense) to fit a keel.


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## CharlieCobra (May 23, 2006)

Yep, we wanted a perfect fit. After the epoxy cured, we again lifted the boat, applied 4200 and reset the boat back on. After that cured, we torqued to final specs.


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## djodenda (Mar 4, 2006)

.. and my bilge is still dry....


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## CharlieCobra (May 23, 2006)

We aim to please....


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## SloopJonB (Jun 6, 2011)

mitiempo said:


> I remember reading years ago that at Hinckley it took days to mate a keel to the hull as the high spots in the lead were planed, fit checked again, etc. Few builders take this kind of care (and expense) to fit a keel.


That's nothing but a waste of time and money IMHO. On the face of it, it sounds like extraordinarily high quality workmanship, but is simply wasteful of time & money to no benefit. Doing the epoxy fairing the way Charlie describes is a fraction of the work and just as effective.

Would you template a lead keel by grinding the lead to shape? Of course not, you'd use epoxy filler on the low spots.


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## SloopJonB (Jun 6, 2011)

*New Forun Suggestion*

How many out there support the idea of an entirely new forum called "The CharlieCobra Forum? 

All of us who do the heavy work on our own boats would find it very useful I think.

It could be blacked out within Charlies market area, like football games.


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## mitiempo (Sep 19, 2008)

SloopJonB said:


> That's nothing but a waste of time and money IMHO. On the face of it, it sounds like extraordinarily high quality workmanship, but is simply wasteful of time & money to no benefit. Doing the epoxy fairing the way Charlie describes is a fraction of the work and just as effective.
> 
> Would you template a lead keel by grinding the lead to shape? Of course not, you'd use epoxy filler on the low spots.


On the other hand, have you ever heard of a Hinckley with keel problems?


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## SloopJonB (Jun 6, 2011)

mitiempo said:


> On the other hand, have you ever heard of a Hinckley with keel problems?


Nope, but neither have I heard of it when faired like Charlie suggests (barring an inadequate mounting system of course). Mated surfaces are mated surfaces, unless they are achieved with something like a thick built up face of soft or brittle material.


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## mitiempo (Sep 19, 2008)

Charlie's method is a good one and one I have recommended before. 

But I think to a certain extent it is a shortcut for a builder to take rather than a good fit to start with.


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## SloopJonB (Jun 6, 2011)

mitiempo said:


> Charlie's method is a good one and one I have recommended before.
> 
> But I think to a certain extent it is a shortcut for a builder to take rather than a good fit to start with.


I agree if it's being used to fair out gross irregularities. What I did on my first keel mount was to grind off the coarse unevenness from the lead until only a thin filler coat was required. This took a few hours, not a few days. I really can't see that ONLY trimming the lead does any better, any more than it would for the templating process I referred to.

To compare it to a different situation - I have heard of high end auto painters wet sanding paint jobs with 3000 grit sandpaper. Since coarse polishes are much coarser than that, what did they achieve other than being able to charge the customer for a lot of wasted hours?

An old friend of mine was an amazingly skillful and artistic woodworker, among other artistic talents. He would not use a router jig to cut dovetails. Instead, he used a marking stencil, the same size and pattern as the router jig, to lay them out. He then hand cut them. Supposedly this was "better" and more "craftsmanlike". In reality, due to using the layout tool, they looked *exactly* the same as the machined ones only they weren't as tight due to the very slight errors that hand cutting introduced. Was that "better quality"? I never thought so.

WoodenBoat magazine is full of these sort of Luddite attitudes - hacking out a keelson with an adze instead of a power plane etc.

I've run across many of these sort of supposed "quality work" situations over the years and have always had the same reaction - unimpressed. If you can't see or feel or derive any REAL benefit from it then IMHO it is simply OCPD, not craftsmanship. The old saying "The right tool for the job" should include "and process" IMHO.

Of course, if you are doing it purely for your own soul satisfaction, go ahead, but when it's a business and someone else is paying the freight, efficiency is expected.

Or am I just a Philistine?


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## CharlieCobra (May 23, 2006)

Nope, not at all. When I do rolling bevels or box section scarphs for a stick I use machine tools where I can. Much faster and usually better control. I have a set of hand planes but they're much slower because if ya set them too deep they tear out chunks. For see through thin shavings for that final finish touch, hell yeah I'll break 'em out.


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## SloopJonB (Jun 6, 2011)

CharlieCobra said:


> Nope, not at all. When I do rolling bevels or box section scarphs for a stick I use machine tools where I can. Much faster and usually better control. I have a set of hand planes but they're much slower because if ya set them too deep they tear out chunks. For see through thin shavings for that final finish touch, hell yeah I'll break 'em out.


Thanks Charlie. When do you start your forum?


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## mitiempo (Sep 19, 2008)

I was just pointing out what Hinckley apparently does when mating a keel to a hull. I wouldn't do it that way either.

But I think the keel/hull joint should be a close fir from the factory that doesn't need an epoxy fairing to fit, not the sloppy fit you often see.


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## CharlieCobra (May 23, 2006)

SloopJonB said:


> Thanks Charlie. When do you start your forum?


Yeah, like that's gonna happen. :laugher


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