Broken Keel Bolts - Hunter
- Thread starter fconmass
- Start date
the bolts had some rust on them, not bad, no different than any others I have seen on other boats. I did not expect bolts to snap when torqued. So just beware if you decide to investigate yours.
Frank
Hinckley is a top quality yard so i d be interested to know the cost if op is comfortable disclosing it
? Wonder if a standard survey would consider putting a torque wrench on the keel bolts... likely not.! Wonder if a purchase contract for an old boat should require passing the torque wrench test as a condition of sale ?
? Wonder if a standard survey would consider putting a torque wrench on the keel bolts... likely not.! Wonder if a purchase contract for an old boat should require passing the torque wrench test as a condition of sale ?
That is what started all this with the keel. Surveyor did not mention keel bolts at all. Hinckley checked torque on bolts and broke 2. The bolts, initially, did not look bad in my opinion but looked like they were rusted (weakened) inside? There is a couple of Utube videos, search, "JibSea", that shows issues with the last aft bolt. Any older boat that has this bolt on keel design should be looked at more seriously at survey time. The cost was about $7000.00.
I have another question; After launching this boat, water began leaking from the last aft bolt on the keel. We are not 100% sure where the water is coming from yet, however, I did not realize that the ice box and , I think, the air conditioner condensation tray drains into the shower sump area. We suspect this shower sump area is right next to where the last bolt location is. Water is not only seeping up through the last bolt location but is backing up up through the shower drain as well. The sump pump has a manual switch in the head, and it is not automatic. The sump hole is not accessible. We are replacing the pump. Does anyone have any experience with how to keep this shower sump hole clear of water automatically?
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 23,078
Sure. Install an automatic pump switch. Then when the sump has water in it the pump automatically turns on.
Hinckley Yacht Services sure sounds like a professional yard. Funny that they did not have the correct size deep socket needed to "check" the torque on the nuts. How does a full service yard fail to have a common tool? They did have a torque wrench, but nobody seems to know what the correct torque specification is. I question the need for a torque wrench when the specification is given as "about".
It is also my belief that it would be impossible to check the torque on nuts that have been tightened and subjected to bilge conditions for almost 30 years, without first removing the nuts, then cleaning and oiling the threads. Aside from the normal corrosion you would expect, there might also be some galling of the stainless steel. Any of these conditions would render a torque check useless, and I believe it is responsible for the snapping of the stainless threaded rod. Looking at the pictures of the "snapped" threaded rod, it is obvious that the rod failed exactly at the point of the contact with the nuts where the maximum force was applied.
I am neither an engineer or a metallurgist. I welcome any comments as to my assertions. It is also my belief that Hinckley is negligent and caused the owner a $7000.00 repair. I find it funny that there are no pictures provided of the original threaded rod, but there are pictures of the snapped threaded rod with nuts attached that conveniently do not show the condition of the threaded rod. I think it would be helpful to see what the actual condition of the original threaded rod was, and it would even be more useful to have a sample of the rod tested for strength.
It is also my belief that it would be impossible to check the torque on nuts that have been tightened and subjected to bilge conditions for almost 30 years, without first removing the nuts, then cleaning and oiling the threads. Aside from the normal corrosion you would expect, there might also be some galling of the stainless steel. Any of these conditions would render a torque check useless, and I believe it is responsible for the snapping of the stainless threaded rod. Looking at the pictures of the "snapped" threaded rod, it is obvious that the rod failed exactly at the point of the contact with the nuts where the maximum force was applied.
I am neither an engineer or a metallurgist. I welcome any comments as to my assertions. It is also my belief that Hinckley is negligent and caused the owner a $7000.00 repair. I find it funny that there are no pictures provided of the original threaded rod, but there are pictures of the snapped threaded rod with nuts attached that conveniently do not show the condition of the threaded rod. I think it would be helpful to see what the actual condition of the original threaded rod was, and it would even be more useful to have a sample of the rod tested for strength.
I like the fix you did with the coupler. Any updates on how it is holding up?
No problems at all after 5 years. The nuts have stayed tight and there has never been any water enter the bilge from the sea. I still tap the tops of the bolts with a brass hammer to check that the couplers are making solid connections with the old studs. This fix is only for keel bolts that have suffered from crevice corrosion in the bilge, not for bolts that have failed between the bottom of the bilge and the keel.
The #1 keel bolt, starting #s at the bow, had the copper grounding wire wrapped around the keel bolt and compressed between two washers from the factory before the floor pan was installed in the hull as there would be no way it could have been done later.
Of course this bolt is completely hidden and only visible through removing the glued in place head/shower drain.
It will not be easy to drill/chisel/grind out the glass around the bolt for the coupler and I will probably have to make another access hole in the floor near the blue cushion to get the job done.
I wish this was accessible as the ones on your H27.
Of course this bolt is completely hidden and only visible through removing the glued in place head/shower drain.
It will not be easy to drill/chisel/grind out the glass around the bolt for the coupler and I will probably have to make another access hole in the floor near the blue cushion to get the job done.
I wish this was accessible as the ones on your H27.
About the only solution I can think of is to cut an access window in the pan above the broken keel bolt. It appears from your photo that the copper wire wrapped around the bolt exacerbated the crevice corrosion.