GRRRGH Keel Bolts

[FParth]

Well, it's been a productive weekend working on the boat. Productive at this stage means I'm getting good at ripping things apart. (Carefully, however, so's I don't damage anything else and taking pictures so I can put everything back together later).

But one keel bolt near the ballast keel is going to be the death of me. The head corroded right off. But nothing, and I mean nothing, is getting that damn bolt to move. I can pound from above with a 3 pound sledge (all I have room to swing) and it just sits there. I can pound it from below and it doesn't budge. I've even tried putting a 10 ton car jack under it with a welding steel rod in between and the only thing that happened was the rod starting to bow.

So I fixed myself a margarita and decided to call for help.

Gentlemen (and ladies) I'm asking for other options. Drill it out? I'm as likely to get the drill bit next to the bolt and drill a new hole in my keel instead. What else can I do?

The other keel bolts I've gotten out so far have been corroded clean through (pix on my site here: http://www.fparth.com/H28/2001/H28closeups.html). This may be the bolt that's holding things together.

Fair winds and safe harbors.

[Robert Nesbit]

A desperate trick to getting a bolt to fail is liquid nitrogen. A friend of mine was redoing the motor mounts on his elderly Chris Craft and could not get some hardware loose despite all his best efforts. I'm a physician so he hit me up for some liquid nitrogen we use to freeze warts off with. He had learned this trick working on boats in Florida. He reported that it worked beautifully with no damage to the wood...I trust him...but did not see the process or the result. Maybe some body else knows more.

[ford]

could you use a power wedge, these are sometimes used to pry apart car accidents and can be had from most tool hire shops.
another method perhaps is to use a cutting wire [don't know the correct term for it]to make a slot around the bolt and try to hacksaw?? the bolt off, that way it may be easier to tackle the remains. :confused:

[RGM]

The margarita was an excellent idea, perhaps two. I take it that this diificult/impossible keel bolt is only in wood? As far as you can tell there is no metal of any kind making contact with it? Take a good look at the location, what's the chance that it is pinned in place by another fastener that may be coming from a different but intersecting angle? Sometimes, depending on the location of the bolts these things can get cross-pinned by other bolts, drifts or spikes. It can frequently happen when you are working close to the stern post and/or a bunch of the deadwood. Other than "close to the ballast keel" I don't know exactly where you're working. What is restricting your hammer swinging room? Can you remove the interference and then swing away with a larger hammer? Honestly, a 3 pounder isn't much, you need something larger. I've used a 60 pounder before (successfully) on keel bolts. Seriously, x-raying can come in handy, up here it cheap. Good luck.

[ 05-27-2002, 10:58 PM: Message edited by: RGM ]

[FParth]

Thanks for the responses. I think RGM has probably the best approach (I would have no clue where to get liquid nitrogen or the devices the emergency responders use to raise heavy vehicles).

I know I'm not anywhere close to a cross-bolt or anything else. The thing is just jammed in there good. The wood swelled around it and has it in a death grip.

What's getting in the way of swinging a heavy hammer is the deckhouse. On the top of the bolt I'm inside the deckhouse, and I don't have a lot of swinging room below it from the outside. But it's a good thought and maybe I'll borrow a serious sledge hammer and have a go at it.

"When all else fails, don't use force, just get a bigger hammer."

Fair skies and safe harbors.

[Concordia..41]

Do you have room to get and electric hammer in a direct line over the keel bolt? I plan to try one to remove the keel bolts from Sarah's cast iron ballast. They rented one at the yard to get the concrete out of the bilge of a shrimp boat and it did a good job. Also one of the Concordia owners used one to get his keel bolts out. Will let you know how it works when we try it.

Sara's keel bolts were all in good condition, not rusted to an hour glass shape where the ballast jointed the keel. See post on page 2 of building and repair. Margo will post there when we do remove the keel bolts.

You can get liquid N2 at a welding supply store. I have used it to put a freeze seal on large water lines that needed repaired and could not be shut off. Just be real careful if you use it as it will freeze you hands or any other part of the body. This is an instant freeze so wear protective clothing, welding or heavy gloves, face shield etc.

Dave

[Jeff H]

All of this discussion of hammering is going the wrong way. Hammering is the worst thing that you can do with a failed keel bolt as I learned the hard way. Typically when a keel bolt corrodes through, the two halves come to a point and roughly look like a marlin spike at each end. When you pound on a keel bolt, the two points deform and wedge one against the other. The more you pound the more they wedge.

You are almost always better trying to us a puller rather than a pusher. When I restored my Folkboat, I ended up removing the floor timbers to gain better access to the bolt and used a car jack to pull out the upper part of the bolt and then drove out the bottom half after soaking it in liquid wrench. This worked on the several bolts that I had not tried to drive out.

I ended up spending a lot of time drilling out the remaining bolts. I used a 1/4' drill bit and drilled down the center of the bolt and then chased it with progressively larger bits until I reached the eventual 5/8" diameter of the holes. In most cases I only had to drill out the top of the bolt and then drive out the bottom of the bolt. In the worst case. I could not get the bottom bolt out and could not get into a position to drill it out. On that bolt, using a tap, I threaded the cast iron approximately 12 inches deep (16 bar diameters), used a larger diameter monel bolt and, in what I now regard as an unnecessary and a dumb move, epoxied the bolt in place. I decided to epoxy the bolt because at some point down below the 12" depth, the 5/8" drill bit had wandered and wallowed out a small cavity and I wanted to seal up the mess down there.

To extend the drill bits I had a local welder weld steel rod onto the end of the drill bits as there was not adequate room for the drill and bit before hitting the underside of the deck on the longer holes. As much as I hate to say it, removing recalcitrant old keel bolts during a Miami summer was the most miserable job that I have ever done on a boat but the good news is that you only have one to wrestle with. Good luck,

Jeff

[FParth]

Jeff,
"...but the good news is that you only have one to wrestle with."

At least up until this point. There are more bolts to go.

Those are good thoughts on getting it out. I tried pounding harder from the top and only succeeded in bending the 3/4 inch that's sticking out above the frame. The bottom part of the bolt is, of course, inset below the surface of the frame so there's no way to get a grip on it and pull it.

I may end up having to drill it out after all. It's a half inch bolt, so starting with a 1/4 inch bit may be the right thing to do. My success record in drilling out planking screws is pretty poor. I always seem to wander next to the screw rather than straight down it. Any thoughts on how to avoid this are highly welcome.

Fair winds and safe harbors.

[Noah]

Well I had good luck pulling out the keelbolts in my Folkboat. I removed the floor, but left the bolt inplace. This meant that I had 16" of keelbolt sticking up, with a nut on top of it. I then built a fulcrum out of 6" angle iron that I could slip around the bolt, but pull against the nut. I used a 4 ton jack, and pulled the bolt up and out.

It worked pretty well. It took about 5 minutes of constant pressure to get the bolt to move though.

Maybe you could weld on a longer threaded rod, and try this approach?

Noah

[ 05-28-2002, 12:04 PM: Message edited by: Noah ]

[FParth]

Noah,
That's a good thought. I've never done any welding before (obviously I'm new to rebuilding boats), but maybe can get a friend to do it for me. When the suggestion was made to pull the bolt out it sounded like a good idea but I couldn't visualize any way to get enough of a grip on it. Welding might work.

Maybe I'll try drilling up the center from the bottom, and, if that doesn't work, try the welding approach. I like having backup plans.

Thanks,

[Jeff H]

Noah really has the right idea. In rough terms that is what I did on the ones that I pulled. Drilling is miserable and should be a last course of action.

Jeff

[Concordia..41]

Noah - Removing the floor (which has to be removed anyway) to gain better access! What an intensily logical thought! There's just nothing like being smacked upside the head with a good idea! :cool: :cool:

Another great example of the Forum's value!

We've still got to get the keel bolts out of the iron ballast keel, but your idea will save us much grief of the rest.

- M