Broken Keel Bolt

[Fernando 15012]

We have our 1982 H30c out on the hard for a compression post support repair. Decided to take the two most adjacent keel bolt nuts and washers to make the re-glassing process easier. With less than 1/4 of a turn and no effort at all the first bolt snapped. In looking closer at the broken piece, it looks like it was over torqued at some point and a crack which runs the length of 4 full threads allowed water intrusion into the core and corroded the bolt. All other bolts are fine. Need help in the following:

1. How are the keel bolts attached to the keel itself.
2. Is there anyone who would have a repair for this without having
to remove/replace the keel.

 

[kloudie1]

Not 100% sure on this but the bolts are cast into the keel when it is poured. They cannot be easily removed.. A good machine shop that does portable services could drill out the first 4-6 inches of old one and tap the hole for a new stud.. Since that keel is lead, the stud should be as long as is practical.
This is not inexpensive work. Ask around, a good yard in Pensacola should be familiar with working that problem.

 

[Capt jgw]

Was they're ever water leaking up through the bolts, and on the outside of the keel files out look like the lead has separated from the fiberglass keel stub at all? If yes, it's likely the bolt sustained crevice corrosion from being wet on an oxygen deprived environment. That is death to stainless steel. It's not from over torqueing the bolt, and likely more or all the bolts are in the same condition. This is not an uncommon condition, and can be very expensive to repair. If the bolts are cast in "J" bolts they cannot be removed easily. The fix is to foster them with new bolts with nuts imbedded in the lead, inserted through holes cut in the side of the keel.
I would recommend dropping the keel to inspect the bolts. You cannot see of they're corroded in the holes with the keel attached. You can use a "nut buster" to split the nuts instead of unscrewing them, this will not do further damage to the bolts.
I'm looking at doing this job on my Columbia 36 this winter, the bolts have been weeping water for years and I'm to scared to run it another year that way.

 

[Fernando 15012]

No water leaking through the bolts and keel has been checked by boatyard maintenance with no evidence of water intrusion. I was afraid of the "J" bolt configuration so, will continue the search for a repair. Thanks for the inputs, they are all welcomed.

 

[RoyS]

On a previous boat, a 1970 Catalina 27, I had a similar problem. Catalina supplied a repair procedure that while difficult was accomplished and worked well. All dimensions here are from memory and should be considered nominal. That procedure was similar to that described above by Capt jgw. It called for having a machine shop cut 2" pieces of 1" stainless steel round bar and to drill holes sideway through the center of each piece and to tap the holes for 3/4" SS threaded rod to be the new keel bolts. Several 1-1/2" holes were drilled completely through the lead keel horizontally about 3" down from the connection point to the hull. Clearance holes in pairs for the 3/4" threaded rod were then drilled vertically down from the bilge to intersect each horizontal hole in the keel. Each horizontal hole would then have two new keel bolts installed. The hole on the lead keel was then filled with fiberglass. I recall that it was difficult to determine where to drill to make these holes intersect, especially the first set. The lead keel was surprisingly difficult to drill as well. These new bolts were placed in pairs between the original bolts which were left as is, in place. Worked for me but I would not want to do it again. Good luck