I know you simply want to know "what sealant" ..... I'm sure that's why you seem argumentative with the responses..... but..... since no one has supported your desire to seal the bolts from the top..... then your answer would be .... NO SEALANT.
Sealing weeping keel bolts.
- Thread starter jviss
- Start date
As the old saying goes....Hey, that's what I said!!!
"To reiterate again...."
You did say so, indeed.
Cheers,
I had a lower shroud chainplate fitting on a Catalina 25 suffer from stress corrosion leading to cracking and catastrophic failure while sailing. Sounded like a rifle shot. Didn't lose the rig, the fitting was nothing more than an eye bolt through the deck, not connected at all to the hull. Water had leaked into the joint and it ate away at the notch of the threads eventually getting too thin to take the load. Very spectacular. I wouldn't want it to happen to my keel!!
The tensile strength of each keel bolt is enough to support the static weight of the keel with a lot of safety factor left over. The issue is more in bending and dynamic loading if the keel flexes that strength will be an issue. As far as torquing bolts in the water, no reason not to but the torque should be increased a bit to allow for the weight of the keel. At the very least torque them to spec and see if they turn at all, will be a good test to see if they are loose. Some fairly easy mathematical formulas are available to convert torque to clamping force. 100 foot pounds of torque exerts an enormous axial load on a bolt. You probably have 7 or so bolts so the clamping force on the keel is a lot.
The tensile strength of each keel bolt is enough to support the static weight of the keel with a lot of safety factor left over. The issue is more in bending and dynamic loading if the keel flexes that strength will be an issue. As far as torquing bolts in the water, no reason not to but the torque should be increased a bit to allow for the weight of the keel. At the very least torque them to spec and see if they turn at all, will be a good test to see if they are loose. Some fairly easy mathematical formulas are available to convert torque to clamping force. 100 foot pounds of torque exerts an enormous axial load on a bolt. You probably have 7 or so bolts so the clamping force on the keel is a lot.
We dropped and rebedded the keel of a CS36M a few years back. You have to lift twice to do it right. First time to get the boat off and clean things up. Then, using plastic packing tape on the hull for a mold release, spread thickened epoxy about a 1/2" deep on the entire surface (have tape around the outside of the top of the keel to keep epoxy from oozing out and sticking), set the boat on it and tighten the keel bolts to about 50 FtLbs. Clean away the ooze for a few hours. Come back the next day, loosen the bolts, lift the boat, peel the tape and seal with 4200 or 5200, set the boat back on and torque her up. The join will be a perfect join that the sealant will keep dry.
There is no empirical data available to evaluate the fairly reasonable presumption that when water stops flowing into your bilge it will corrode the keel bolts significantly faster. Apparently, these bolts have corroded to near catastrophic failure conditions before on similar boats, so fair warning on not addressing it as soon as you can afford it. One of those sealants probably says it's more permanent and stronger than the other one on the label, which means it's harder to separate what you have bonded together with it, harder to remove from surfaces that it has cured to, and probably a little less likely to fail when applied by the manufacturers instructions.
Personally I would sell my boat before going through all that crap of dropping a keel & rebedding it. I like my boat, but don't love it that much. At the end of the day, it costs a lot of money to do this, & as mainsail said no Catalinas have lost a keel yet. These boats are all getting long in the tooth, & at a certain point you have to do preventative maintenance yes, but if your going to rebuild your boat, make sure its really worth it.
ps. To that quote about Holmes on Homes, I work as a professional building inspector & much of what he does is complete overkill. I kinda wonder who's paying for the bill when he almost destroys homes for the purpose of a fishing expedition. If I lived in South. Cal. in eathquake country, then yes by all means overbuild. But this is a good comparison between the keel bolts / Catalina smile problem. Repair & glass it over from the outside & torque the bolts, she'll be fine for a good many more years.
Here's what one of our skippers did: http://c34.org/bbs/index.php/topic,6842.0.html
I just had our (much smaller) smile cleaned, refilled and painted.
I just had our (much smaller) smile cleaned, refilled and painted.
YET! Yet is the key word.
I can nearly guarantee that these boats will begin to lose keels, if preventative maintenance is not done, it's just a matter of time vs. corrosion..Ideally I think any decision to re-set a keel should be based on % of value of the boat and the % of money you've already invested. Also consider what a boat with a bad keel joint is worth on the open market and what losing a keel could potentially mean. Sometimes it will be best to cut the losses and run and other times the condition and market value of the boat make it a reasonable expense..
I have a customer right now with a 70's Pearson 30. The boat has bad decks and the insurance company will not insure the boat until the chain plates and deck have been addressed. (discovered during a mandatory insurance survey)The boat has a newer diesel but is still worth just about what the repairs will cost if it was in perfect condition. In the condition it is in now it is worth about what the used diesel engine is worth at fair market value and the hull is a liability. The owner has not yet decided how best to proceed..
I am not going to get into the debate on how/when/if you should repair your boat. You asked what type of sealant one would use to seal a weeping bolt. I would Boatlife's Lifecaulk. Just squeeze some out all over the stud & nut and smear it around with your finger to totally cover it all. This stuff dries, even when wet. It may take multiple applications to totally stop the leak.
I think you stated the problem well Mainsail with the example of the 70's Pearson. To me, while I do love Good O'l Boats, I just can't fathom spending many thousands on rebuilding a very common & dated designed production sailboat. It she were a rare boat, special in some unique way or design, was in otherwise excellent condition, or I had a LOT of time & money on my hands, then maybe. But I'm a practical sailor, & I just can't throw that much money into a hole in the water. That said, I would feel pretty guilty if the keel were to ever drop from beneath the boat! I would be more concerned about my family's safety, but I think that my boat is in pretty good shape for her age, all things considered. Cheers.
What "completely separate concerns" do you have in mind? Just curious....Internal ballast boats have their own completely separate concerns, so they need not feel smug, either....
Sorry to take so long to check back in on this thread. If you have an Ericson, there are several threads over on the owners' site that talk about internal ballast and issues to watch for.
While there are no inheirent gross disadvantages, there is always the possibility of damage to the botton of the keel cavity from a hard grounding.
Remember that the lead casting that was lowered down into that hollow was never an "exact" fit. If water comes in from a crack or more damage it will fill the gaps and rise up to threaten the interior of the boat.
Many boats, like the classic Cals in the 70's have a sump behind the lead that's large enough for a bilge pump (lowered down on a board, about four feet) to scavenge water from the very bottom.
My only point was to say that all ballast solutions do have their plusses and minuses.
Loren
No problem, the keel fell off, the rest is history.
Just kidding!
It turns out it was fresh water in the bilge, and it was coming from a leaking water heater. I guess 28 years is the limit on a Seaward water heater, eh? Not so bad in that a replacement is under $300, but it's probably a ton of hours to replace.
I've since bypassed the water heater and sponged out the bilge and it's dry.
Thanks,
jv