|Topic Review (Newest First)|
|06-20-2005 04:36 PM|
Keel Bolt question
Thanks for the description of your approach to this repair. Now I ''m really looking forward to it... ;->
|06-20-2005 02:33 PM|
Keel Bolt question
I have done this operation a number of times and it is not easy.
First, it is entirely possible that only one of the keel bolts is stricken with the contaminates that cause the electrolysis and subsequent weepage of rusty water. That is possible. In many situations where I have found this phenomenon (Chain plate bolts on old Sabres, for one) your heart leaps into your throat as a bolt crumbles in your wrench when you were ''just checking nut tension''. Then after desperate securing of the rig, get new fasteners for all the chainplates, and lo and behold, it was only the one bolt. Go figure.
However, who wanted to risk that?
Keel bolts fall into the same category, only they are 75,813 times more difficult to work on. Here''s what you have to do.
Drop the rig and haul the boat. Sailboats without keels don''t do well in windstorms. Use at least 4 to 5 stands on each side of the boat as well as one under the bow and one under the stern. Make sure they are chained and secured, and the screws are greased. Carefully and slowly circle the boat (I always do this alone so I have complete control over the balance of the boat and the equal tension of the stands) and tighten the stands one at a time, about 1/2 to 1 turn each.
Be careful, don''t rush, watch everything. If you hear any crunching or see any hull buckling you don''t like, back off and put big plywood supports between the stand and the hull there, or move the stand a little if you have to. Keep going until the bottom of the keel is about 1/2 inch of the ground.
Secure everything and make sure the boat is solid.
Go aboard and carefully remove all the keel nuts and washers. IF YOU HAVE TO BUY SPECIAL SOCKETS AND BREAKERS BARS, DO IT!!
These are far too important to bugger for a cheap tool.
If the keel is properly bedded, you will have noticed by now that it didn''t drop. DO NOT BE TEMPTED TO HAMMER THE KEEL BOLTS!!
I just love the ''all caps'' thing, don''t I?
Anyway, now, get the deepest hole saws you can that will fit ovet the keel bolts, with just a little room to spare. They have some 2 1/2 to three inches deep.
Start carefully running the hole saw over the bolts as far as they will go, beginning with the front one, the the most rear one, then the second front one, and the second rear one, etc. Have someone outside tell you as the belly flexes and the keel begins to pull away.
when you are on the very last bolt, the keel will settle on the ground and the belly will pop free.
As long as the keel bolts are still in the holes, the boat is perfectly stable.
At this time, I build a very solid brace around the keel with bolted 2 x 6''s and I don''t spare the wood or fasteners. I want to be able to lift this hull clear if I have to, which sometimes, I have had to.
Then, with the boat stands, lift the boat about one more inch, still leaving plenty of bolt up in the hulls bolt holes. Carefully clean EVERYTHING and inspect completely. By this time, you should have plenty of spectators offering tons of advice. Listen carefully to what they say about bedding.
I have done it two ways.
One boat separated awesomely cleanly leaving two fine fair and flat surfaces. I used a thick layer of Boatlife Lifeseal and squeegeed off the excess. Perfect seal and no problems to date. (About ten years)
On the other, the top of the keel was a mess of casting shrinkage and crap. I had to clean it for about three or four hours, prep the surface carefully, and trowel in a layer of West Epoxy with Colloidal Silica thickener, being excrutiatingly carefull to match the flat surface of the hull above so it would sit perfectly flat and straight. Once that cured, a bit of clean up and lifeseal.
I am thinking that if you have bad keel bolts, there will not be more than one or two, and they may only be pitted around some manufacturing impurities. If it is more, or they are very bad, then you need to change them.
The best way is to go into the side of the keel about six inches from the top with a 2 1/2 inch hole saw and some drills and a torch (very carefully) to expose the shank of the keel bolt. Sever the bolt as low as possible with an air die grinder. Lower the hull and put some sacrificial nuts on the bad bolts, then hammer the top of the studs so the nuts cannot be backed off. Making sure that there are no burrs on the severed end of the keel bolt, start working the bolt out with the breaker bar abd socket. You might have to use oil or some impact. Try not to get tempted to heat it up with a torch - thats how boats burn - but if you have to, with the right precautions, that is the final solution.
Fit nice big nuts into the holes in the side of the keel and run new threaded rod in from above. Snug it up, make a small coffer dam over the lower 3/4 of the holes and fill them with molton lead. Finish it up with a small torch and smooth it. use acid like a plumber.
Raise the boat, apply sealer and put her back down. If you have not moved either the boat or the keel (except up and down) it has to land exactly where it was.
Before installing the washers and nut above, be sure to remember to fill the voids around the keel bolts with West epoxy using the plungers. All filled up. No bubbles or voids. Weight down on the keel, bedding, washers, nuts, proper torque (about 150 to 175 for your boat, but double check to be sure)
just a thought
|06-19-2005 04:49 AM|
Keel Bolt question
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?