Mailport February 15, 1999 Issue

Mailport 02/15/99

Keel Bolts
Your October 1, 1998 issue had a PS Advisor on keel bolts. My experience removing large nuts and bolts on B 52 bombers in the 60’s was to use a blunted chisel set in a rivet gun to pop them and then spin the nut off with a finger. The bolts started out with a punch set in the same rivet gun, then a rolling wedge was used under the head to remove the bolt.

William Schueler
Wichita, Kansas

I was intrigued at the recent discussion of keel bolts. I have a 1968 Columbia 36 and have been interested in making preemptive replacements of my keel bolts. Of course, for a boat of this vintage, cost is important. Up to this point I have been gathering information and thought I would pass along the consensus that has emerged.

In collaboration with other naval architects we have determined that removing the existing keel bolts will be a frightful job, too big to be worth undertaking. In my bilge, however, there is room for me to add between two and five additional bolts.

The idea is that the present bolts are still doing their job (the keel hasn’t fallen off). So don’t disturb them. Instead, focus on supplementing them with additional holding power.

This can be accomplished by drilling downward from the bilge all the way through the lead and out the bottom. (Tedious, but not actually hard.) Keel bolts pressed in from above would then receive nuts and washers at the bottom. The nuts and washer can be countersunk into the lead by heating with an oxyacetylene torch.

The proposal I like best for keel bolt material thus far is to make them of Aquamet shafting material. A machine shop can cut a thread onto Aquamet. Aquamet is so high in yield strength (180 ksi if I recall correctly) that quite a small bolt diameter will result in more than adequate restraining force. (The Columbia 36 would produce about a 10,000 lb. static tension in the bolt at 90° of heel. A robust safety factor suggests that I should have bolts capable of, say, 50,000 lbs. aggregate. Two 1/2" bolts at 180 ksi gives a total bolt strength of 70,000 lbs.)

Chris B. McKesson, PE
Bremerton, Washington

I own a 1972 Columbia Mk II which has an iron keel with “wings” inserted into the hull, bedded and bolted. While prepping for a single-handed race to Bermuda and back, checking my old keel bolts became an obsession. I also believed that if I dropped the keel, it would never go back as solidly as the original. One day out of the blue, it occurred to me, “Why not just put six brand new bolts right beside the originals?” A good drill bit, new bolts and nuts, interior steel cross bars, compound and lots of arm power and presto, eight hours later six new bolts plus six old bolts (that were probably okay to begin with) and peace of mind. I slept well, albeit only an hour at a time.

Edward A. Caswell
Wakefield, Rhode Island

I just replaced keel bolts last spring and will give a bit of a different technique which was used on my boat.

I own a 39' white cedar strip-planked Wiley-built sloop which was put in the water in 1956 and has been maintained wet ever since except for hauling and bottom painting. She has a cast-iron keel with galvanized keel bolts. Thus they’ve been in the water for 42 years in the Chesapeake.

I thought the bolts had been replaced in the 70’s but was told “no” when she started to leak around the aft ones. The aft two were completely dissolved and the next two were virtually gone in the area where the iron was joined to the hull. In fact, the keel had started to separate on the aft end. Close call!

New stainless bolts were installed with a rubber compound and they were torqued down through steel plates which run from knee to knee at each bolt. Then the keel was drilled and Kevlar cord was epoxied from waterline to waterline using the patented Cutts Method. This has given us a dusty dry bilge with cobwebs! My daughter-in-law who was afraid of sinking now worries about spiders!

All this was done at the Cutts and Case yard in Oxford, Maryland and was not inexpensive—about $2,000 per bolt. But we now have a completely dry boat with no worries for the next 40 years at least. No one knows how long Kevlar will last but it will hold the keel without bolts. Our keel problems are solved.

We waited too long to correct our problem. I expect we’ll pull one or two bolts in a few years to check the stainless.

George A. Delatush, MD
Tequesta, Florida

On older European boats, the keel bolts were often steel and had to be examined visually at regular intervals. More recently, providing the ballast is iron, the bolts can be X-rayed in situ. This is not the case with a lead keel which will shield the X-rays. Consequently, on Lloyds +100A1-classed vessels, mandatory visual inspection of selected keel bolts is part of the regulations for reclassification every eighth year at survey. Bolts are drawn, inspected and, if necessary, tested to destruction. After a given length of time, the surveyor will insist on the keel being dropped and all the bolts being inspected and probably replaced. This becomes doubly important with the increasing use of stainless bolts and the discovery of crevice corrosion.

In the US, most owners appear to give little thought to their keel fastenings and because of the expense involved bolts appear to be little tested or inspected at survey. Probably this is due to the high quality of construction used on traditionally built boats in the US with extensive bronze reinforcements and bronze or Monel keel bolts. However, modern production boats tend to use stainless bolts and this can give rise to serious problems. Clearly, as yet there has not been a spate of keels dropping off or separating on grounding or else insurers would insist on inspection.

There is one relatively inexpensive method, adopted by the US Navy, and this is ultrasonic testing of keel bolts, which will give an indication of condition, dezincification or granular structure.

Patrick Matthiesen
Sparkman & Stephens Association
London, England

You advised the gent who inquired that there was really no way to examine the keel bolts in place. I’ve had a very knowledgeable ultra-sound guy (he was checking my steel hull at the time) tell me that with the proper equipment he could (and had) shot down the bolt from the top and pick up any significant indentations resulting from corrosion. He led me to believe that he changed some parameter in the sending unit which resulted in an ability to look gradually further and further down the bolt.

David Masters
via e-mail

The J/32
I agree with the plus and minuses concerning the J/32 mentioned in your October 1, 1998 report. I have owned hull #25 for more than a year; we keep it moored in the Bahamas. As a sidekick, I race a J/80 in Annapolis. Because of old age, I traded my C&C 41 for a lighter vessel which my wife and I can push off the dock in a blow.

As far as stowage is concerned, I have to agree that I had to rethink how to arrange things. I don’t know what you mean by “additional stowage is accessed through a removable panel in the galley,” unless Alan Johnstone made some changes since I bought mine. Next to the galley, a door opens to a large walk-in space (if you bend your head) with plenty of room, but I agree that it requires some imagination how to arrange things. The bottom line is that I find as much space to hide sails, tools and other gear as in my C&C 41 or the earlier C&C 35.

I too miss a seat at the navigation table, particularly in rough conditions. And to check—or even worse—to remove the batteries under the nav table requires a contortionist. But you have to compromise if you want to have an unusually roomy interior.

These minor disputable shortcomings are offset by the excellent construction, hardware and thoughtful deck layout which make the J/32 fun not only for shorthanded cruising but also racing, even with the shoal keel.

Peter Heidenberger
Man-O-War Cay, Bahamas

Where Credit Is Due...
To Leatherman Tool Group: “I sent a note to Mr. Leatherman complaining that my Philips screwdriver tended to fold up when any pressure was put on it. I received a note inviting me to return it for repair as a better design had been created. The tool was returned with a note indicating that the wire cutters, knife blade and medium screwdriver had been replaced as well as the Philips. In truth, I think they sent me a new Leatherman.”

Storm Connors
Pleasant Valley, Connecticut

To Recovery Engineering: “When we took the life raft from our newly purchased Cambria 40 to be serviced, the technician informed us that it contained a PUR Survivor 06 water maker that looked to be beyond hope. We sent the unit to the manufacturer, Recovery Engineering, with a request for an estimate to repair. To our delight, they offered to rebuild and upgrade the unit and did not charge us.”

Robert McArthur
Auburn, Maine

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