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Hey everyone,

So I'm doing some homework, and I'm looking at a Columbia 39 that needs a keel bolt replacement job in the near future (but otherwise seems to be in great shape). Could anyone give me some advice as to whether or not this is a many thousand dollar job or multi-hundred type of repair? I don't have the skill to do it myself, so I'd have to have a pro do it for me which of course would up the cost, but for something like this, I'm sure it's worth it.

Or is replacing the keel bolts "too" big a job, and I should pass on this one?

Thanks!
 

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Drop the keel, replace the keel J bolts in the lead keel and reinstall would be $15K to $20k. Drop the keel to inspect the J bolts and found to be good, seal and refasten the keel with new nuts. $8 to 10k.
If everything else is in good shape and they give you the boat then it might be worth it
 

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When you say "replace the keel bolts" do you mean:

1) Replacing the NUTS and washers on the bolts that you can see inside the bilge.

OR

2) Dropping the keel and replacing the entire stud you see coming out of the lead itself?

Two drastically different jobs.

I would also say if you think the nuts need replacing then it would be also worth assuming the studs need to at least be inspected by dropping the keel. Not a small job but if the nuts are that corroded away to warrant replacing then the stud may be suspect.
 

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I may be remembering this incorrectly, but my recollection is that the Columbia 39 has a cast iron keel with a flange cast in. That flange sits in a molded in recess in the hull and has bolts which simply pass from the flange into the hull and looks something like this:
Columbia Keel by jeff_halp, on Flickr


If that is the case, and you do much of the work yourself in terms of cleaning the bedding materials off the keel and out of the recess, then its not a bad job. It would probably be closer to a $2,000 job than it would be to a $5,000 Job.

There is no point in simply replacing the nuts since the keel bolts can be removed without dropping the keel, although it probably makes sense to drop the keel, and redo the bedding if you are going to replace the bolts.

Jeff
 

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I've often thought about how to DIY person would do Keel bolts on-site on iron and or lead.

Iron of course can be drilled and tapped and maybe with any kind of luck perseverance and the proper drill bits (meaning, not home center drill bits) iron would actually be easier is what I'm thinking,

Lead of course it's easy to work, drill and even use lag bolts on,. But, to burn / melt existing Keel bolts out and cast the lead, could actually be more difficult and working with iron?
 

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I've often thought about how to DIY person would do Keel bolts on-site on iron and or lead.

Iron of course can be drilled and tapped and maybe with any kind of luck perseverance and the proper drill bits (meaning, not home center drill bits) iron would actually be easier is what I'm thinking,

Lead of course it's easy to work, drill and even use lag bolts on,. But, to burn / melt existing Keel bolts out and cast the lead, could actually be more difficult and working with iron?
If I had to replace keel bolts in a lead keel that had J-bolts (or worse yet U-bolts) as a DIY, I would do it the way that a lead keel was historically bolted into a wooden boat. I would cut off the old bolts flush with the top of the keel. I would set up a boring jig and drill new keel bolts several feet down into the lead close to the old keel bolt locations. I would then precisely locate the position of the end of the new bolt holes and drill a larger hole perpendicular to that point to create a nut pocket. I would tap the bottom end of the new keel bolts, put sealant in the hole and slide the keel bolt into place and then put a nut, bearing plate, and washer on the bottom the bolt where it entered the nut pocket. Then peen the bolt end and fill the nut pocket with a filler.

If you do that you need to make sure that you carefully rebuild the sump to make sure it isn't weakened by all of the holes, Lastly, a template would be made locating the new bolt positions and a jig rigged to carefully drill the new bolt holes.

The rest is the same as any keel rebedding process.

Jeff
 

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I was thinking the same thing Jeff! Cross dowel bolts kind of like bed bolts only larger
 

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Discussion Starter #8
Wow, great info. Thanks guys!

So depending on what needs to be done, it sounds like this repair job could run the spectrum from the low end of 2k up to 20k. That's quite a range there. The boat itself "appears" to otherwise be in good shape, so it's still on my short list of boats I'm considering.


>>1) Replacing the NUTS and washers on the bolts that you can see inside the bilge.

>>OR

>>2) Dropping the keel and replacing the entire stud you see coming out of the lead itself?

>>Two drastically different jobs.

...I don't know the answer to this. I only have the info the owner gave me, and she mentioned that the bolts are soon due to be replaced. I would imagine the survey would (hopefully) be able to tell me which type of job it is.

:)
 

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The picture Jeff posted was my keel on my Columbia 43 which is the same setup as the 39.

Iron keel with 10 - 3/4 X 10TPI studs in 5 pairs. I had the studs cut from S/S allthread and had S/S channel backers cut to replace the stock mild steel ones.

If I had it to do over I'd get Titanium studs & nuts instead of S/S - the cost differential is minimal in the greater scheme of things and you never have to worry about galvanic or other corrosion again.

I dropped the keel to re-seal it but if your isn't leaking I'd recommend against it - re-fairing it is a brutal job because of the recess in the hull that the keel sits in. If it's not leaking just do the bolts & backer in pairs - you can do this in the water if you want - there is a huge safety margin on those things. The yard moved my 10,000 Lb keel around with only 2 "grade nothing" bolts holding the chain sling to it.

Here are pics of samples of the old & new hardware on mine.
 

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Wow, great info. Thanks guys!

So depending on what needs to be done, it sounds like this repair job could run the spectrum from the low end of 2k up to 20k. That's quite a range there. The boat itself "appears" to otherwise be in good shape, so it's still on my short list of boats I'm considering.


>>1) Replacing the NUTS and washers on the bolts that you can see inside the bilge.

>>OR

>>2) Dropping the keel and replacing the entire stud you see coming out of the lead itself?

>>Two drastically different jobs.

...I don't know the answer to this. I only have the info the owner gave me, and she mentioned that the bolts are soon due to be replaced. I would imagine the survey would (hopefully) be able to tell me which type of job it is.

:)
I don't think that a survey will tell you anything useful about whether the bolts need to be replaced unless the situation is really awful and so the bolts are visibly shot. Given the way these boats are built, replacing just the nuts and washers would be a useless waste of time and money since the studs fail below the nuts and washer where you can't see them. Plus replacing the studs and channel isn't all that expensive in the overall realm of things.

SloopJonB nailed it in his answer. These are not lead keels but cast iron keels with threaded in studs. JonB has been there with this on his own boat which is a bigger version of this boat and built the same way.

Jeff
 

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The picture Jeff posted was my keel on my Columbia 43 which is the same setup as the 39.

Iron keel with 10 - 3/4 X 10TPI studs in 5 pairs. I had the studs cut from S/S allthread and had S/S channel backers cut to replace the stock mild steel ones.

If I had it to do over I'd get Titanium studs & nuts instead of S/S - the cost differential is minimal in the greater scheme of things and you never have to worry about galvanic or other corrosion again.

I dropped the keel to re-seal it but if your isn't leaking I'd recommend against it - re-fairing it is a brutal job because of the recess in the hull that the keel sits in. If it's not leaking just do the bolts & backer in pairs - you can do this in the water if you want - there is a huge safety margin on those things. The yard moved my 10,000 Lb keel around with only 2 "grade nothing" bolts holding the chain sling to it.

Here are pics of samples of the old & new hardware on mine.
 

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I'm dealing with the keel on my Columbia 43. It has SS studs also. I've been wondering how much torque to apply. How much did you put on your bolts? Did you figure it out on your own or find out from someone what the specs were?
 

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I'm dealing with the keel on my Columbia 43. It has SS studs also. I've been wondering how much torque to apply. How much did you put on your bolts? Did you figure it out on your own or find out from someone what the specs were?
I looked up bolt torque specs on the Interweb.

Bolt torque depends on the bolt material, size and thread count - bolts don't care if they are holding a keel on or a bridge together.

Here's one chart.

137232
 

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I looked up bolt torque specs on the Interweb.
I'm not sure if those are reliable enough. Jeanneau publishes the torque for our keel bolts in a very wide range. About 500-1000 ft lbs. Yes, the range was that wide. I don't recall the exact metric size, but they're approx 1.25". When I changed ours out, I initially tightened to the middle of the range, 750 ftlb. Then, after one season, I had them re-torqued to 900 ft lbs.

I did the 750, with my son and a friend on torque multipliers and 5ft bars. Then I paid someone else to do the 900!!
 

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I'm not sure if those are reliable enough. Jeanneau publishes the torque for our keel bolts in a very wide range. About 500-1000 ft lbs. Yes, the range was that wide. I don't recall the exact metric size, but they're approx 1.25". When I changed ours out, I initially tightened to the middle of the range, 750 ftlb. Then, after one season, I had them re-torqued to 900 ft lbs.

I did the 750, with my son and a friend on torque multipliers and 5ft bars. Then I paid someone else to do the 900!!
If you look at a number of those charts you will find they agree in a pretty close range - 3/4" X 10TPI runs right around 125 Lbs/Ft for S/S.

It's standard engineering specs.
 

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I looked up bolt torque specs on the Interweb.

Bolt torque depends on the bolt material, size and thread count - bolts don't care if they are holding a keel on or a bridge together.

Here's one chart.

View attachment 137232
Thanks. Appreciate the response. I've seen these charts, too, but then I see all kinds of complicated formulas for the actual torque you need for a given, what is it?, clamp load or preload, which I interpret as the weight that the bolts are holding (i.e., the cast iron keel, in our case, which is 10,300 lbs according to my specs). The number of bolts is a factor, too, right? I assume, since we have the same model boat, that you have 3/4"-10 UNC S/S bolts (looks like you have coarse thread, like me), 10 in number. I also have the channel backers, although they are galvanized steel, so I'm not too worried about crushing the laminate (I don't think). I'm just looking for a number in the range I would be going for so I can invest in a proper torque wrench. Since you've evidently done it, I was hoping you could give me a number. Did you just use the 128 in the chart then?
Another question, if you don't mind, the four forward bolts are extremely difficult to get to on my boat. How are they on yours? The ones you picture, like mine, are easy to access. It would be virtually impossible to extract any of the forward four because there would be no room to pull them out (well, the ones next to the mast might be extractable).
Anyway, I do appreciate your response and would appreciate any more info you might have. Would like to check my bolts' torque and see how far off they might be.
Thanks.
 

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Thanks. Appreciate the response. I've seen these charts, too, but then I see all kinds of complicated formulas for the actual torque you need for a given, what is it?, clamp load or preload, which I interpret as the weight that the bolts are holding (i.e., the cast iron keel, in our case, which is 10,300 lbs according to my specs). The number of bolts is a factor, too, right? I assume, since we have the same model boat, that you have 3/4"-10 UNC S/S bolts (looks like you have coarse thread, like me), 10 in number. I also have the channel backers, although they are galvanized steel, so I'm not too worried about crushing the laminate (I don't think). I'm just looking for a number in the range I would be going for so I can invest in a proper torque wrench. Since you've evidently done it, I was hoping you could give me a number. Did you just use the 128 in the chart then?
Another question, if you don't mind, the four forward bolts are extremely difficult to get to on my boat. How are they on yours? The ones you picture, like mine, are easy to access. It would be virtually impossible to extract any of the forward four because there would be no room to pull them out (well, the ones next to the mast might be extractable).
Anyway, I do appreciate your response and would appreciate any more info you might have. Would like to check my bolts' torque and see how far off they might be.
Thanks.
It was 15 years ago but IIRC I used 120 Lbs/Ft. As I said earlier, I don't think the torque varies by the number of bolts or the weight they are holding - info like that is what is used to determine the size and number of bolts in the first place.

Full disclosure, I'm not an engineer - just a "talented amateur". 😉

I used a 1/2" clicker torque wrench that I owned but it was pushing its limits. For one job I'd rent a 3/4" wrench instead of buying one - good, accurate ones ain't cheap.

Having said that, accuracy in this instance is not critical like it is when assembling an engine or similar. I can't count the number of times I've heard recommendations like "Put a long pipe on a wrench and tighten until the suckers scream". I think a large proportion of the keels out there have been tightened that way.

I had no problem with any of the bolts but the two forward ones under the sole in the head. I simply cut holes over them and then fitted deck plates to cover the holes.

If you are using mild steel backing channels I highly recommend painting them thoroughly with epoxy paint - so they don't end up like my originals. Also, a bit of a countersink on the glass will vastly improve the effectiveness of the sealant you use under them by creating an O-ring effect. That will help to prevent the oxygen free environment that causes crevice corrosion where the bolts pass through the bottom of the hull.
 

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It was 15 years ago but IIRC I used 120 Lbs/Ft. As I said earlier, I don't think the torque varies by the number of bolts or the weight they are holding - info like that is what is used to determine the size and number of bolts in the first place.

Full disclosure, I'm not an engineer - just a "talented amateur". 😉

I used a 1/2" clicker torque wrench that I owned but it was pushing its limits. For one job I'd rent a 3/4" wrench instead of buying one - good, accurate ones ain't cheap.

Having said that, accuracy in this instance is not critical like it is when assembling an engine or similar. I can't count the number of times I've heard recommendations like "Put a long pipe on a wrench and tighten until the suckers scream". I think a large proportion of the keels out there have been tightened that way.

I had no problem with any of the bolts but the two forward ones under the sole in the head. I simply cut holes over them and then fitted deck plates to cover the holes.

If you are using mild steel backing channels I highly recommend painting them thoroughly with epoxy paint - so they don't end up like my originals. Also, a bit of a countersink on the glass will vastly improve the effectiveness of the sealant you use under them by creating an O-ring effect. That will help to prevent the oxygen free environment that causes crevice corrosion where the bolts pass through the bottom of the hull.
Great. That's really useful information. That's what I had been thinking (and doing) all these years--just tightening them as much a possible--but one starts reading about keels and all the various ideas people have and the confusing technical aspects. I may reseat the keel, though...it is leaking. But it's been leaking ever since I bought it 27 years ago
;-) (I didn't know about it when I bought it). I'd like to sell it now though, and it would be a lot better if I just solved the problem and could pass it on knowing it was in really good shape. Meanwhile, I'll check the torque on my bolts. Thanks again.
 

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If you see leaks, it's almost certain that the bolts are compromised. The real telltale is if you see rust weeping out anywhere. With a iron keel this is not a bad job at all. Remove all the nuts and have the yard lift the boat off the keel. (Build a framework around the keel first, you don't want it to tip over. As I told my yard guys, "if this thing tips over, I can guarantee I'll be under it at the time". As I recall my yard charged me a total of $200 to lift and reblock, then lift and replace the boat after. Then unscrew the old bolts and clean both surfaces. Hopefully they are not so corroded that they break off. Still fixable, just more complicated. Replace the bolts and reseal the bed when they put the boat back on. I used 5200, as hated as the stuff is this is one of the two places where it's appropriate. The other is the hull/deck joint. These are what it was developed for. The yard bill should be the biggest expense here. Mine was.
 

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If you see leaks, it's almost certain that the bolts are compromised. The real telltale is if you see rust weeping out anywhere. With a iron keel this is not a bad job at all. Remove all the nuts and have the yard lift the boat off the keel. (Build a framework around the keel first, you don't want it to tip over. As I told my yard guys, "if this thing tips over, I can guarantee I'll be under it at the time". As I recall my yard charged me a total of $200 to lift and reblock, then lift and replace the boat after. Then unscrew the old bolts and clean both surfaces. Hopefully they are not so corroded that they break off. Still fixable, just more complicated. Replace the bolts and reseal the bed when they put the boat back on. I used 5200, as hated as the stuff is this is one of the two places where it's appropriate. The other is the hull/deck joint. These are what it was developed for. The yard bill should be the biggest expense here. Mine was.
This is what I did. I took the time to fill & fair the top of the keel to ensure a tight mating surface with the hull rebate. Chased the keel threads with a bottoming tap to ensure they were clean and as deep as possible. Countersunk both ends of the holes in the hull to ensure the best possible seal of the bolts in the "dead air" space where they passed through the glass. Installed the studs using double nuts and then re-mounted the keel.

Filling & fairing the joint was most of the work - brutal job because it's all "uphand". A piece of radiator hose wrapped in sandpaper was the best tool I found for fairing the "garboard radius".
 
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