Sistering my I-28s keel bolts?

[downeast450]

I have decided not to add 4 "sisters to the keel bolts in my Islander 28. I discovered the condition of the stub is sound. What I thought was the surface of the lead keel was a 1/2" steel plate. No lead is visible as per this post. My mistake. I do not like the condition of the exposed bolts. They ring true. The threads above the nuts are rusted to the point that they could not be engaged by the nuts if I backed them off. There is no leak associated with the keel. A visible seam is present but no latent wetness after hauling.



What worries me now is the amount and location (above the steel plate) of sealant visible in the bilge. IS THAT NORMAL? There is copious "sealant" around the perimeter of the stub. I would expect sealant would be used to bed and attach the lead. Why would it be above a steel plate that is part of the stub? I was planning to eliminate the original knot meter's thru hull that was moved by a PO from the side of the keel to a spot just above the turn of the bilge. It has a plug living there now. Considering the glass work involved with that and the anxiety surrounding the condition of the original bolts I decided to spend a week and lay up enough new glass structure to support a sister. I have the tools and experience to do the modifications to the hull. What I don't have is any experience with keel bolts!

Now I am deciding on the material for the new bolts. Any suggestions? SS seems logical but it will be encapsulated inside the keel. I am thinking of 1.25" or a little larger steel. Since I will be building the bilge beds for these new bolts I can raise them a bit higher that the originals to keep them out of any bilge water. The originals are steel and have lasted in terrible conditions since 1977.

I have a good laminate schedule including Kevlar but wonder if I should build in a steel shoe at each new bolt location and how far it should extend laterally?

I expect that when all the glass work is complete I will have covered the inner surface of the keel completely. I have to decide how to treat the existing bolts. I am thinking that a good wire brushing and then just work the new laminate around them can't hurt.

To keep the work area free of styrene I will be using System Three laminating epoxy resin. I plan to drill the holes in the lead before doing the glass work. I have practiced drilling into lead. That can be tricky and I welcome your suggestions. I will plug the holes with a piece of wood for the glass work and remove it when I am ready to install the bolts.

I will alternate sides for cutting the slots into the keel for the lower nuts and washers.

All comments are most welcome.

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[mitiempo]

Lead visible in the bilge? Sounds pretty strange. Do you have any pictures? The hull should be pretty thick in way of the keel stub.

[Maine Sail]

Keel bolts are almost always cast in place J or L shaped bolts. Threading and tapping lead yields little strength. I would wait to do it right and that generally means dropping the keel, putting it on a pallet, and shipping it to Mars Keel so they can totally replace the keel bolts with the Mars process...

The barrel bolt method is ok and stronger than just threaded into lead..

[downeast450]

Hi Maine Sail,

I was not considering threading into the lead. I intend to drill into the keel and then from the side cut a slot so a nut and washer can be attached to the end of the bolt about a foot down into the keel. I can then apply upward pressure by tightening the keel bolt nut in the bilge. The end of the bolt in the keel will be in a "socket" I will fill and fair.

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[downeast450]

Brian, I will post a couple of pictures later in the week. it looks shaky to me but no signs of leaks, yet.

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[Don Huseman]

I made the Islander keels for Islander. The keel bolt were gavanized steel. Islander told me to use this material. the bolts were bent into a J and cast in the keel. I think this is correct this is going back 30 years ago and I think this is correct. I now sister in keel bolts into the keel through the hull and then into the keel. At my old company called Keelco we did test on keel bolts pulling out of lead and found that unless you drilled and tapped the keel bolt in at least 10 inches into the lead the bolt would slowly pull out. This is called creep. If you look at an old glass window that has the glass saging that is an example of creaping.
In order to do a good job you have to drill down at least 10 inches in the lead and then tap the hole. The more practle way to do it is drill down and then pocket the stud in. You should drill down about 6 to 10 inches. stager the depths of the holes so you won't make a weak line of holes accross the keel. Put on a nut or a rectangular ss steel washer and then seal it up with epoxy and fiberglass. This is a more practile way to sister in new keel bolts. I drill and tap in new keel bolts because I do it on a daily basis and have taps that are 3feet long and drill that are 18 " long. I also us a drill press that is specialy set up to do this type of work. But pocketing is the best way for an individual to do this type of work. I would charge about 230 per bolt. I fly all over the country.
Don Huseman 310 5474604

[downeast450]

Don,

Thanks for the reply! I am getting closer to working on my keel. "Other things" have delayed my work but it almost time to begin. I plan to drill down from the top of the keel inside the boat and open a "pocket" to add a washer and nut to the end of the bolt in the lead. Thanks for suggesting that I stagger the depth of the holes. Do you have any suggestions RE: the drill bit type required? A source of a bit that will drill a hole for a 1" bolt that extends 12 inches into the lead is where I am now. What bit will I need? Where can I get one? Will a wood auger do the job? How do I drill the hole? I am planning to practice on an old lead keel I have. I have a 3/4 inch variable speed drill. It will be hand held since I can't get a drill press into the boat's bilge. I intend to rig a counter weight to help me support the drill. It could break your wrist if it fetched up and spun the drill. I am guessing that a very slow rpm and some lubricant? What works with lead? 12" is a deep hole to keep a 1" bit plumb in. Should it be done with a pilot hole first?

As I drill down into the keel I would need to avoid running into an end of the currently installed bolts. I will be drilling in the space between pairs of bolts. Does the bent-in hook run fore and aft? How large was the hook? It didn't need to be very big. Did that alternate with members of a pair of bolts? How did you set them when you cast the keels? How far into the keel do the original bolts sit?

Do you have any knowledge of the original construction of the keel stub? Was there a steel plate in it?

I have asked for a lot of information. Anything you have time to share will be welcome. If I could afford it I would hire you to do it for me but alas this is a tight budget project.

Thanks again,

George

[paulk]

If staggering the depth of the bolts in the lead is a good idea - in order to avoid the "tear off here" syndrome, the same might apply to drilling holes in a line in the bilge. To repair wooden boat keels they sometimes go beyond using hefty washers or backing plates, and install new floors to spread the load to a broader area of the hull and avoid point loads.

[hellosailor]

Don, I think silicon bronze is still considered the most corrosion-resistant (and possibly expensive) metal for the job. The I-28's were built quite heavily though, and unless there is a definite problem you may be on a snark hunt there.

IIRC one of the keel bolts is also blocked by the mast compression post, which transfers to a 4x4 which forms the aft inboard corner of the head compartment, which sits on a "bridge" that blocks access to a bolt, so you are going to have the "mandatory opportunity" to rebuild the head compartment while you are up there, and the flooring under it. (I think there are or were pictures of head/step ebuild of an I28 on the web someplace, don't know if they're still up.)

By the way, I've seen Robert Perry's original drawings for the I28. He designed it with a keel-stepped mast, not the oddball offset into the head that was actually built. The actual build apparently wasn't the same as the original design, in a number of ways. Perry is still corresponding and consulting on these boats--for a fee.

If the only degradation is to the threads that are clear ABOVE the nuts...I'm not sure a project of this magnitude is called for. Compared to a lot of other boats, Islander used a generous number of keel bolts to start with.

And remember, drilling into lead will raise and distribute lead DUST, you probably should be doing all this work with a suitable respirator and ventilation, and then doing a hazmat clean-down in the boat. Lead dust is not a good thing to be breathing, or wearing.

[downeast450]

Paul,

I will be building a new floor between each existing pair of keel bolts. At present (I know this requires pictures) the spaces between the pairs of keel bolts, their nuts, washers and a ring of hard "sealant" has NO FLOOR. There is lead exposed the full width of the stub! This is true of the spaces between the forward pair of bolts to the middle pair of bolts and from them to the aft pair of bolts and from them to the stern most bolt. The perimeter of the stub has a generous ridge of the hard "sealant". There is no floor on the lead surface of the keel. I can not see what kind of "strap?" the existing bolts are mounted through. I don't "see" how they are supporting the keel!!!

I intend to drill 4 holes for sisters. One forward of the existing forward pair of bolts, quite near the "bridge" that supports the mast step. I have enough room to drill the new hole without disturbing the mast step or the head. The second hole will be between the forward pair of bolts and the middle pair. The third hole will be between the middle pair and the aft pair and the fourth hole will be between the aft pair and the aft most bolt. It is my plan to insert a dowel, to be removed later, into the drilled holes and lay up a floor right on the lead using laminating epoxy and a suitably robust schedule of roving and Kevlar. I will replace the existing frames as I go, one at a time, using COOSA BLUEWATER composite for the frames and the inner surface of the new floor. The existing wooden frames are glass covered and drilling into them suggests that the wood is quite punky. I will need to temporarily remove two of them to drill the holes anyway. I intend to encapsulate the "old" bolts in the epoxy laminate/floor, too after cleaning the rust away.

Unavoidable delays have prevented any progress on this but it will begin soon. I did manage to find three cement block size chunks of lead out behind the shop. They wait for me on some blocking. I want to have some practical experience with bit selection and drilling speed, lubricant, etc. before I set up in the confined space of the boat. I am expecting that a slow, well lubricated hole will be straightforward.

Amen to protection from lead dust!

Thanks for your comments.

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