37C Aft keel bolt

[joe28532]

Well that sucks. What you're looking at there is a pit that has corroded into the aft keel bolt (the one that is commonly under water). I have owned this boat for about five years and I've always manually pumped out the standing water whenever I left the boat. The plan is to haul out and sister in a new bolt (probably bronze) by drilling down from inside the bilge and then in from the side of the keel to intersect the first hole, then chiseling the intersecting hole into a square pocket large enough to get a backing plate and nut on, then after placing the new bolt and hardware in filling and fairing the pocket with thickened epoxy. This method was described by Don Casey in an article in Sail magazine.

 

[Dalliance]

I looked up and read Casey’s article. Sounds like a good plan. Good luck and please post photos of this project.

 

[Whatfiero1]

I don't see I mean there's a little corrosion on threads but that thing was over engineered in first place. On hull out take a file to straighten threads pull nut off and if no reverse keel smile put some 5200 in hole and put nut back on and tork to 300 ft lbs. And call it good

 

[joe28532]

May be hard to see in the picture but there is actually a half pea-sized piece of the bolt missing. By the way the torque spec on those keel bolts is only 132 foot pounds.

 

[Tally Ho]

I don't see I mean there's a little corrosion on threads but that thing was over engineered in first place. On hull out take a file to straighten threads pull nut off and if no reverse keel smile put some 5200 in hole and put nut back on and tork to 300 ft lbs. And call it good

Put 5200 on the hole in the bolt? That doesn’t sound right to me.

Greg

 

[dLj]

The material loss is restricted to the top side of the nut on the male thread? I'd pull that nut off and look at the condition of the rest of the threads inside that nut. If they are OK then that keel bolt is still good. The threads above the nut don't have any load bearing function. You do have to stabilize the corrosion so it doesn't continue down the stud. So if the threads inside the nut on the stud, well also the nut threads, are good then what you are proposing is unnecessary in my opinion.

dj

 

[joe28532]

The material loss is restricted to the top side of the nut on the male thread? I'd pull that nut off and look at the condition of the rest of the threads inside that nut. If they are OK then that keel bolt is still good. The threads above the nut don't have any load bearing function. You do have to stabilize the corrosion so it doesn't continue down the stud. So if the threads inside the nut on the stud, well also the nut threads, are good then what you are proposing is unnecessary in my opinion.

dj

I have considered this. I don't know how I'd feel about removing that nut in the water though. So since I would be hauling out to check it I would probably just go ahead and sister in the other bolt.

 

[dLj]

Sure you know how you feel - nervous as hell! Who wants to unscrew a keel bolt with the keel hanging off it in the water! LOL

If you had no other choice you could do it, buy heck, if you can just pull the boat, no need.

I'd still look at it though. If the damage is only above the nut, that's a lot of unecessary work....But as they say, your boat, your choice....

dj

 

[Dalliance]

When I zoom in to the photo on my iPad, it appears that the corrosion of the bolt extends well below the top of the nut. I would not trust that bolt. In fact, I wouldn’t be surprised if it sheers off with the first try at backing the nut off. Sistering in a new bolt is the prudent thing to do.