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  #21  
Old 10-26-2012
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Re: Grid system repair

Quote:
Originally Posted by davidpm View Post
Thanks for your comments. I'm using this as a learning example. I was able to get pictures but the insurance is held by others so they are handling the final disposition.

I did talk to the yard manager and he has not finished his estimate yet. He is thinking that he should drop the keel to check to see if their is any damage around the keel bolt holes.

By the looks of the keel boat heads they will have to be broken to be removed.
How are keel bolts replaced once they are broken in a steel keel?

I'm familiar with catalina lead keels where they just drill a hole and screw in a giant lag screw but what do they do in iron?
Your keel is held on with (essentially) galvanized bolts. (See photo's attached--I hope!) If you will send me a PM with your email address, I will forward a file produced by Beneteau to address your questions.
Attached Images
File Type: jpg Rusty Keel Bolt Replacement 2.jpg (19.2 KB, 37 views)
File Type: jpg Rusty Keel Bolt Replacement 1.jpg (33.3 KB, 32 views)
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  #22  
Old 10-26-2012
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Re: Grid system repair

I realized I could copy the Beneteau technical notice as a text file (absent photos) and thought that might be worth while. I regret the formating of the tables, below, isn't perfect, but should be understandable.
Background Information
• Cast Iron keel use galvanized bolts - There are threaded sockets cast into the keel
• Lead keels use stainless steel nuts - There are threaded rods cast into the keel

You can use stainless steel bolts in a cast iron keel, but you should remove and inspect the threads for galvanic corrosion yearly.
A bolt only has to engage the threads 1˝ times the diameter of the bolt to be effective. 90% of Beneteau Keel bolts are 3 inches or less in length.

Replacing Information
Use a battery powered drill with a wire brush wheel. Clean the heads down to new metal. Tip: use a shop-vac to clean rust dust and flecks as you clean the heads.

Remove 1 bolt and inspect. At this point you should be able to make a determination if the bolt is structurally sound or needs to be replaced. A complete set of the bolts and washers can ordered from the Beneteau Spare Parts Department. We will need the Model and Type of keel on of your boat.

14mm bolt uses 22 mm socket
20mm bolt uses 1-3/16 socket
30mm bolt uses 1 7/16 socket


If you have water entering the boat through the bolt hole, replace the bolt and make future plans with your local boat yard to haul, separate and reinstall the keel.

If the head of the bolts are so degraded that the socket will not back it out, use a side grinder to grind two flat sides on the bolt. This should allow you to remove the bolt with a wrench. Worst case scenario: Remove boat from the water, grind the heads completely off and remove the keel from the hull. Then using the remaining shaft of the bolt, remove the bolts and reinstall the keel.

Coating the heads of the bolts with a rust preventative paint will prolong the life of the bolts. Tip: I have used Trailercoat from West Marine with success.

Do not use sealant on the bolt threads; only use sealant around the bolt heads to keep bilge water out of the bolt socket.

The keel to hull joint and exterior seam should be sealed with Marine Adhesive Sealant 4200.

Keel bolt Torque Specifications.
DACROMATISED STEEL BOLTS TYPE 8-8.

DIAMETER M14 M20 M24 M30
TORQUE in M.Kg - minimum 5 13 23 45
TORQUE in M.Kg - maximum 9 27 46 90
TORQUE in ft.lb – minimum 36 94 166 325
TORQUE in ft.lb – maximum 65 195 333 651

TABLE 6.5.2
STAINLESS STEEL BOLTS TYPE A4-70 and A4-80

DIAMETER M14 M20 M24
TORQUE in M.Kg - minimum 5 16 28
TORQUE in M.Kg - maximum 11 32 55
TORQUE in ft.lb – minimum 36 116 203
TORQUE in ft.lb – maximum 80 231 398

TABLE 6.5.3
STAINLESS STEEL BOLTS TYPE A4-55

DIAMETER M30 M36 M42
TORQUE in M.Kg - minimum 19 33 52
TORQUE in M.Kg - maximum 38 65 104
TORQUE in ft.lb – minimum 137 239 376
TORQUE in ft.lb – maximum 275 470 752

FWIW...

PS: Keel bolts can be replaced, one at a time, while the yacht remains in the water. And, when I replaced our keel bolts, I coated them with Petit RustLoc primer--several coats--to good effect.
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Last edited by svHyLyte; 10-26-2012 at 12:07 PM. Reason: Correct typo; Add PS.
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  #23  
Old 10-26-2012
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Re: Grid system repair

Quote:
Originally Posted by svHyLyte View Post
Your keel is held on with (essentially) galvanized bolts. (See photo's attached--I hope!) If you will send me a PM with your email address, I will forward a file produced by Beneteau to address your questions.
SV - does Beneteau use cap screws to attach their keels? I've never seen that done - it's always been studs threaded into the keel and attached with nuts inside the bilge.

Except for small keels that is - Thunderbirds keels are held on with countersunk flathead machine screws through the flange of the root of the keel.
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  #24  
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Re: Grid system repair

Quote:
Originally Posted by SloopJonB View Post
SV - does Beneteau use cap screws to attach their keels? I've never seen that done - it's always been studs threaded into the keel and attached with nuts inside the bilge.

Except for small keels that is - Thunderbirds keels are held on with countersunk flathead machine screws through the flange of the root of the keel.
Beneteau's cast iron keels are secured with "DACROMATISED STEEL BOLTS TYPE 8-8" which are essentially galvanized bolts as discussed above (see photo attachments to my earlier post #21). This manufacturing process is evidently not uncommon with European performance yachts. Beneteau's Lead keels are fastened with nuts tightened down over stainless steel studs cast in place in the keel during manufacturing. One can use stainless steel bolts (in cast iron keels) but, if so, they must be inspected annually for crevice corrosion and getting them out (and there are 16 of them) is a serious PITA. After 26 years, I needed to replace 8 of 16 bolts because of the corrosion of the bolt heads due to the failure of the water-proof coating and some water having made its way into the bilge (which is normally so dry it's dusty). In fact, upon extracting the bolts we found that only a small portion of the bolt heads had actually deteriorated and that the shafts, threads et al were dry, clean and as shiny as the day they were installed in 1986.

FWIW...

PS: Interesting that you should refer to T-Birds. Our first real yacht--other than a sailing dinghy--when we lived in San Francisco was a late 1950's era T-Bird with the cast iron keel fastened as you described. Believe it or not, I still have the plans. Great boats.
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  #25  
Old 10-27-2012
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Re: Grid system repair

Quote:
Originally Posted by svHyLyte View Post
if so, they must be inspected annually for crevice corrosion and getting them out (and there are 16 of them) is a serious PITA. After 26 years, I needed to replace 8 of 16 bolts because of the corrosion of the bolt heads due to the failure of the water-proof coating and some water having made its way into the bilge (which is normally so dry it's dusty).
So from your point of view putting a wrench on a keel boat, even if it is in water, extracting to take a quick look is a fairly routine project?

That takes yacht maintenance to a new level. I've always thought of extracting the keel boats as a once in a lifetime exercise.
Maybe because I'm more familiar with the Catalina system where the bolts are cast into the keel and the keel has to be dropped to check anything other than the nut and a inch or two of the top of the bolt.
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Re: Grid system repair

Quote:
Originally Posted by davidpm View Post
So from your point of view putting a wrench on a keel boat, even if it is in water, extracting to take a quick look is a fairly routine project?

That takes yacht maintenance to a new level. I've always thought of extracting the keel boats as a once in a lifetime exercise.
Maybe because I'm more familiar with the Catalina system where the bolts are cast into the keel and the keel has to be dropped to check anything other than the nut and a inch or two of the top of the bolt.
David--

The lead keels on Bene's that have cast in studs would be akin to the Catalina design although more robust. If you look at some of the other postings/threads on the subject, several members have posted photo's of what their keel studs looked like once the keels were removed and some are quite frightening. That is not the case with Beneteau's cast iron keel design. Removing a bolt while the yacht is in the water is not a big deal as there is no distortion of the hull due to the weight of the yacht sitting on the keel alone, hence the seal between the keel and the keelson is not compromised. If one does observe water seepage upon the removal of a bolt, it will be minimal but it will also be a telltale that one needs to drop the keel, clean up the top of the keel and the underside of the hull, and rebed the keel. There should not be any water penetration between the two as rust can/will form and force the two apart--just as rust on re-bar will blow the side out of a concrete column or beam, frequently seen on old bridges or retaining walls. The resulting stress in the keel bolts will further compromise the seal admitting more water and the cycle will continuously repeat itself until there is a failure although that would take a very long time absent an exogenous shock load.

In any case, I have never heard of anyone pulling a keel bolt and having water intrusion on a Bene. I'm sure it may have happened, but I have personally not heard of such a case. The only situation where I could see that happening might be where the bolts were not torqued sufficiently (see the torque tables in my earlier post). For our part, I torque the bolts to 150 ft-lbs and our bilge is as dry as a bone. And, I will not pull a keel bolt unless there is some evidence that it is necessary as I do not use stainless bolts in an oxygen deprived environment. (In fact, save for rigging, I don't think much of stainless.)


FWIW...

PS: David. Note that only the Stainless Steel Bolts need be removed for annual inspection (per Beneteau's recommendation). The galvanized bolts do not.
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Last edited by svHyLyte; 10-27-2012 at 11:40 AM. Reason: Add Post ******
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Re: Grid system repair

As I alluded to a while back - this is one of the benefits of iron keels. Keel stud problems on a lead keel are a major headache and big expense to fix but in most cases they are but a minor job on an iron keel.

As to removing individual bolts at the dock, keep in mind the huge safety margins designed into keel mountings. When my 10,000 Lb keel was off to be blasted, sealed & remounted the yard moved it around with a sling that was only attached with two of the 10 keel bolts - no problem.
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Re: Grid system repair

" this is one of the benefits of iron keels."
All in perspective. This system is AFAIK used on iron keels simply because the simpler cheaper traditional j-bolts aren't feasible in cast iron. If using studs to attach a keel really was a better way to do things, it would be simple to insert a metal plate in the top of a lead keel as it was cast, and then drill down into it so the same type of replaceable studs could be used. But designers seem to prefer J-bolts, probably for a reason. Of course the use of stainless may be a mistake but that dates back to the WW2 ear when "STAINLESS!" was marketing magic. And so many people still think it is.

I give credit to B for thinking outside the box in many ways but they also seem to think routine replacement of those keel studs is normal. J-bolts in a lead keel? OK, so you replace the nuts if you need to, rarely the bolts. PITA if you have to but that's what owner neglect causes, RFPITA.

Why folks don't do a little routine maintenance, apply some oil, grease, put a collar around the bolt head and pour in hit beeswax, just SOMEthing once or twice a year and the whole question of corrosion should be a non-issue, regardless of the metals or keel type.

I'd still prefer a lead keel over iron, which may be a great budget helper, but iron is still fat and cheap no matter how you look at it. Of course my real choice of ballast is the same one that NASA used on the Mars Rover shield: Tungsten!

Makes lead look fat and cheap.

Please save up all your tungsten incandescent light bulb filaments from burned out bulbs, I'm building a proper tungsten keel, 1/10th of a gram at a time. (VBG)
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Re: Grid system repair

Quote:
Originally Posted by hellosailor View Post
If using studs to attach a keel really was a better way to do things, it would be simple to insert a metal plate in the top of a lead keel as it was cast, and then drill down into it so the same type of replaceable studs could be used.
That's more or less what they are doing with the current razor blade keels with bulbs 12 feet down. Drilling and tapping takes time which = $$. Usually the builders go for the cheaper option whenever they can.

Quote:
my real choice of ballast is the same one that NASA used on the Mars Rover shield: Tungsten!

Makes lead look fat and cheap.

Please save up all your tungsten incandescent light bulb filaments from burned out bulbs, I'm building a proper tungsten keel, 1/10th of a gram at a time. (VBG)
Why not go for depleted uranium? It's actually been done. There's probably lots of it in the desert in Iraq and Kuwait.
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Re: Grid system repair

Other than toxicity and restrictions on civilian ownership?

IIRC it was Bertie Roos who literally borrowed enough spent uranium to make his keel in one of the Volvo (?) solo global races maybe a decade ago. And when the keel broke off and sunk in the Southern Ocean, I'll bet Bertie had a lot of 'splainin' to do.
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