Keel Bolt Inspection

[gbgreen59]

My 1984 Bene 35' First is in dry storage for the winter (from fresh water). I pulled all of the keel bolts and looked them over. Each bolt is in good shape. There is a little corrosion on the head of the bolt that was exposed to bilge water, but nothing significant. The threads are in pristine condition, with the threads being shiny/bright metal. I cleaned out the caulk in each bolt hole and am ready to clean up the bolt heads, washers and plates.

I noticed that the square plates (about 3" on a side) are cupped up away from the hull. I am wondering if this they should be flat in order to distribute the load. Are they cupped due to the keel forces pulling down on the bolt heads? Should the plates be flattened or replaced? Or are they OK as is?

In addition, I attached a table of torque values to apply to keel bolts. I found this table some time back on another, similar thread. The table gives values for bolts made from various materials. I am assuming that the Beneteau bolts are not stainless steel, since there is corrosion on the bolt head. Am I correct? There is a wide range of torque in the table from the minimum value to the maximum value. Should I try to torque the bolts to the maximum value or hit somewhere in between min and max?

Thanks in advance for your help.

 

[Gunni]

Wow, that is quite the range, similar bolt sized to similar bolt size. When faced with this kind of question I go directly to BeneteauUSA. 843.629.5300 and have them sort things out. Although recently they have often sent me to a local dealer for support..which is not helpful. Given the age and unknown type of bolt you might want to consider replacements of known torque range. BTW, my sq. washers (2004) are also cupped upward, which I assume allows them to seat on a variably flat keel stub. Good luck on this important task.

 

[gbgreen59]

This is very helpful. Thanks.

Gary

 

[gbgreen59]

Interesting progress on finding values for torque on keel bolts...

BeneteauUS directs you to using a dealer via their automatic phone system. The dealer won't provide information due to not knowing the condition of the bolts and keel...fairly understandable...although, it would be nice if they could say, "if the boat was new, here are the values". The recommendation from the dealer is to contact the boat yard where the boat is kept and have them help. Past experience with the yard is that they won't recommend anything; they will only do the work.

I can understand this path quite a bit. It is possible that I could blame them if they provided information to me and then something went wrong. But man, this is frustrating.

Guess I'll just try to hit the middle of the torque values from the table I posted earlier.

 

[Gunni]

I would take a different tack. Tell Beneteau you need replacement keel bolts for your 30 year old Beneteau and let them spec the bolt. They want to sell something to you, take them up on it. I would not re-use a 30 y.o. bolt, you snap one off in the keel and you are neck deep in the Kimchi. Once mine come out, new bolts go back in.

 

[gbgreen59]

Good point and that makes a lot of sense. Thanks

 

[gbgreen59]

I received information from Beneteau on the subject of keel bolt maintenance. It is informative and reinforces the path that I am taking for replacement of the bolts. So, I will reuse the current set bolts, as there is no corrosion on the bolt threads. Also, the bolt threads and bolt holes are dry. The torque for the bolts is as given in the document I shared in the first post of this thread.

At this point, I'm going to get the bolts torqued and sealed. Then, I'll seal the keel/hull joint. I'll keep my eye on the keel hull joint. If the caulk separates, then I'll have the keel dropped and rebed it. That's the plan...been an interesting job and have learned so much.

 

[Ron20324]

.... I noticed that the square plates (about 3" on a side) are cupped up away from the hull. I am wondering if this they should be flat in order to distribute the load. Are they cupped due to the keel forces pulling down on the bolt heads? Should the plates be flattened or replaced? Or are they OK as is?....

I'd say the washers are upwards so there is not a hard "edge" that would be in contact with the hull. That would induce stress at that point, and who knows what kind of wear thereafter.