Select to expand quotetarquin1 said..
Red lead and grease helps. This one was very old not sure how old. We put a new nut on it about 10 years ago. Still looked brand new when we removed it.
You can see the colour difference between 2 bolts. Many different types of bronze. The one on the right is older. Definitely over 20 years, possibly much older.
So yes I am more for bronze.
Silicone bronze is the usual bronze for marine bolt applications. It generally has more of a darker/deeper colour than white bronze which has a higher lead content. Monel is another good alloy for bolts on boats
Select to expand quoteJolene said..tarquin1 said..
Red lead and grease helps. This one was very old not sure how old. We put a new nut on it about 10 years ago. Still looked brand new when we removed it.
You can see the colour difference between 2 bolts. Many different types of bronze. The one on the right is older. Definitely over 20 years, possibly much older.
So yes I am more for bronze.
Silicone bronze is the usual bronze for marine bolt applications. It generally has more of a darker/deeper colour than white bronze which has a higher lead content. Monel is another good alloy for bolts on boats
The keel bolts in Wapiti are 2205 stainless. That's a deliberate engineering (not economic) choice made by the designer and builder, as all the bolts used to fasten the frames to the backbone are bronze.
The keel frame is 2205ss as well, maybe the choice is to avoid dissimilar metals?
I note Tally Ho has bronze keel bolts.
Why is bronze not used widely these days.
New keel bolts should arrive this morning so keel lift booked this afternoon hopefully
hopefully pics tomorrow
while the boat is out other things attended to.
If all organised you get keel off replace bolts and back on in less that 5 days on the hard
Select to expand quotelydia said..
Almost 500 views in 24 hours so at least people are curious!
Sad to say I can't generate any interest on my North Shore Facebook group which has quite a few members
The old and the new!
Pick which end was in the keel?
that was the best stainless bolt by the way
Did not get back on today as travel lift ran late and early next week is crap weather but all good to go.
I thought after almost 1400 views in a week, there might have more discussion.
Anyway!
Maybe people are ignoring what they do not want to believe.
Select to expand quotejulesmoto said..lydia said..
Almost 500 views in 24 hours so at least people are curious!
Sad to say I can't generate any interest on my North Shore Facebook group which has quite a few members
With a NS 38, I thought the bolts are just tapped into the keel, so you could maybe check one at a time in the water.
Of course break one off and you have problem.
Select to expand quotelydia said..julesmoto said..lydia said..
Almost 500 views in 24 hours so at least people are curious!
Sad to say I can't generate any interest on my North Shore Facebook group which has quite a few members
With a NS 38, I thought the bolts are just tapped into the keel, so you could maybe check one at a time in the water.
Of course break one off and you have problem.
Thanks
We did the keel last winter in Italy. In a yard that specialises in classics. They use Sika 298. It's for bonding decks down. A bit thinner than 5200 so you have less chance of bubbles or voids. It has a longer skinning over time as well. You have to be quick so it doesn't skin over. Worth looking into.
Select to expand quotetarquin1 said..
We did the keel last winter in Italy. In a yard that specialises in classics. They use Sika 298. It's for bonding decks down. A bit thinner than 5200 so you have less chance of bubbles or voids. It has a longer skinning over time as well. You have to be quick so it doesn't skin over. Worth looking into.
Will do, sounds good.
Weather will turn today so will a job for Wednesday now.
Select to expand quoteshaggybaxter said..
There ya go.
Already to go, keel all prepared and boat just waiting to be lifted.
alignment checked with a template.
bolts all cleaned up
hull surface cleaned and faired
just need everything to say up right over the next few days as the weather closes in.
Select to expand quotelydia said..
Did not get back on today as travel lift ran late and early next week is crap weather but all good to go.
The genius of S&S design and attention to detail, while well disguised the bearing surface for the top of the keel is surprisingly wide and long but not noticeable at first look.
Again a big rap for the lads at R & M Marine at Kettering, especially Dunc, old school boat builders with attention to detail.
Others would not know what silicon bronze even was or were to get it.
At a different level, on Friday I was asked by the head of safety at Aust Sailing if i would send a zip file of all the photos to the head of the World Sailing Technical Committee who is doing a review of the keel bolt replacement issue.
Select to expand quotelydia said..
I thought after almost 1400 views in a week, there might have more discussion.
Anyway!
Maybe people are ignoring what they do not want to believe.
Silence doesn't necessarily mean disinterest. I'm really interested in the story and the pictures. Kinora has an encapsulated keel but there are other areas where stainless steel meets potentially dissimilar metals and sea water in places that are hidden or not easy to see, so your experiences are directly influencing my list of things to check. As a starter, I now understand another reason the rigger was keen to replace the chain plates.
Thanks for posting, Lydia, and for providing more reasons to worry! Good luck with the rest of the job.
Kinora
This is a very good article for those less hands on like me thanks. I would be interested to know what you found the bolts screwed into and how you check its soundness . In looking the the old bolts I would be concerned. Some years ago I looked at a Farr727 but after reading up on the NZ site was somewhat scared off by the discussions around the necessity of replacing the (special) keel bolts and how to find the nuts in the keel . Below is pic. of a Canadian 727 which is slightly different in format to the NZ boats.
Trick is the find the bolt space and you will usually find these be sanding back as the filler will show up and dig it out.
The really tricky one where there is a cage moulded in to the lead and the tops of the cage is the bolts, so no voids.
If we had have found that the plan was to cut it remove what was left of the threads then install new bolts and washers as shown above.
Also if properly engineered the bolts should be at alternate staggered lengths not all the same length as in the pic above.
On Defiance we assumed rightly that S&S would have specified staggered bolt lengths and plates and nuts set into the keel.
Not all production boats will be like that.
A mate just did his bolts on a Jeanneau 40 and they are just threaded into the keel so easy to remove and replace.
All where totally shot btw.
About a 2 day job to remove and re-seat and relaunch but that was as simple as it gets as keel was not removed just bolts replaced because of the method of construction.
If you have a cast iron keel as many production boats do you will likely find that the bolts are simply tapped into the cast iron with no nuts etc. It saved time and cost in production.
Select to expand quotelydia said..
Trick is the find the bolt space and you will usually find these be sanding back as the filler will show up and dig it out.
The really tricky one where there is a cage moulded in to the lead and the tops of the cage is the bolts, so no voids.
If we had have found that the plan was to cut it remove what was left of the threads then install new bolts and washers as shown above.
Also if properly engineered the bolts should be at alternate staggered lengths not all the same length as in the pic above.
On Defiance we assumed rightly that S&S would have specified staggered bolt lengths and plates and nuts set into the keel.
Not all production boats will be like that.
A mate just did his bolts on a Jeanneau 40 and they are just threaded into the keel so easy to remove and replace.
All where totally shot btw.
About a 2 day job to remove and re-seat and relaunch but that was as simple as it gets as keel was not removed just bolts replaced because of the method of construction.
If you have a cast iron keel as many production boats do you will likely find that the bolts are simply tapped into the cast iron with no nuts etc. It saved time and cost in production.
Lydia thank you for taking the time to post such detailed posts , what happens if you have a bolted on lead keel? I heard you can't just screw in new keel bolts like you can with the modern cast keels.
Select to expand quoteMAGNESIUM said..lydia said..
Trick is the find the bolt space and you will usually find these be sanding back as the filler will show up and dig it out.
The really tricky one where there is a cage moulded in to the lead and the tops of the cage is the bolts, so no voids.
If we had have found that the plan was to cut it remove what was left of the threads then install new bolts and washers as shown above.
Also if properly engineered the bolts should be at alternate staggered lengths not all the same length as in the pic above.
On Defiance we assumed rightly that S&S would have specified staggered bolt lengths and plates and nuts set into the keel.
Not all production boats will be like that.
A mate just did his bolts on a Jeanneau 40 and they are just threaded into the keel so easy to remove and replace.
All where totally shot btw.
About a 2 day job to remove and re-seat and relaunch but that was as simple as it gets as keel was not removed just bolts replaced because of the method of construction.
If you have a cast iron keel as many production boats do you will likely find that the bolts are simply tapped into the cast iron with no nuts etc. It saved time and cost in production.
Lydia thank you for taking the time to post such detailed posts , what happens if you have a bolted on lead keel? I heard you can't just screw in new keel bolts like you can with the modern cast keels.
There will either of these:
1. Like Defiance with washer to screw into in void in the keel.
2. A plate moulded into the lead to screw into
3. A cage of reinforcing rod a bit like you see with reinforced concrete piling and the ends will be threaded and they are the ends of the keel bolts. These were common in 1970 and early 1980s production boats. As posted above we were just going to cut the cage and start again.
There will be boats with galvanised keel bolts, i would to see how that have stood up as not subject to the crevice corrosion but have different issues.
You simply have to have a look to see what you have then work out the plan of attack.
So as a synopsis, what we learn from your posts is that the only way to check your keel's attachment is to remove it and re-attach.
This seems totally reasonable and I for one am seriously considering doing this to my 30 year old boat before I do anything serious with it.
What bothers me though - when I consider the outworking of this - is that whilst evidently the current keel inspections are useless, if you mandated keel-off checks at even 10 years, you wouldn't have prevented any of the high profile keel-loss incidents of recent years. All the ones I can think of either had modified keels (so new bolts surely), or the boats themselves were less than 10 years old.
Do you think we're going to see keels coming off these old boats over the next 10 years?
Select to expand quotelydia said..
Again a big rap for the lads at R & M Marine at Kettering, especially Dunc, old school boat builders with attention to detail.
Others would not know what silicon bronze even was or were to get it.
At a different level, on Friday I was asked by the head of safety at Aust Sailing if i would send a zip file of all the photos to the head of the World Sailing Technical Committee who is doing a review of the keel bolt replacement issue.
Well done. New version of the ISO code coming in 2025 apparently............
www.researchgate.net/publication/379120751_Regulatory_Developments_in_Structural_Keel_Design_A_Revised_ISO_12215-9
Was all keen to check my keel bolts when I bought my NorthShore 3 or 4 years ago but it has an internal liner so the nuts are significantly below the internal liner floor level and the removable timber part of the floor is only about 350 wide from memory.
I purchased a beefy socket and was able to torque the nuts up very slightly with the assistance of a long-handled racheting torque wrench.
Even purchaced some new nuts as I thought I could undo the bolts once locked to the secondary lock nuts but once I put the lock nuts on I can't get at the lower nut to remove the bolt. Needed the right size long arm ring spanner with a really big crank in it which also needs to ratchet otherwise it fouls other parts of the internal liner. Eventually gave up on the idea.
I'm sure knowledgeable shiprights have the answer to the till issue but I don't. Got as far as a quote for keel removal from a shipwright at Marmong Point but went no further. Have to get onto it again after this post.
Select to expand quoter13 said..lydia said..
Again a big rap for the lads at R & M Marine at Kettering, especially Dunc, old school boat builders with attention to detail.
Others would not know what silicon bronze even was or were to get it.
At a different level, on Friday I was asked by the head of safety at Aust Sailing if i would send a zip file of all the photos to the head of the World Sailing Technical Committee who is doing a review of the keel bolt replacement issue.
Well done. New version of the ISO code coming in 2025 apparently............
www.researchgate.net/publication/379120751_Regulatory_Developments_in_Structural_Keel_Design_A_Revised_ISO_12215-9
Who happens to be an author of that paper!
Select to expand quoteJonE said..
So as a synopsis, what we learn from your posts is that the only way to check your keel's attachment is to remove it and re-attach.
This seems totally reasonable and I for one am seriously considering doing this to my 30 year old boat before I do anything serious with it.
What bothers me though - when I consider the outworking of this - is that whilst evidently the current keel inspections are useless, if you mandated keel-off checks at even 10 years, you wouldn't have prevented any of the high profile keel-loss incidents of recent years. All the ones I can think of either had modified keels (so new bolts surely), or the boats themselves were less than 10 years old.
Do you think we're going to see keels coming off these old boats over the next 10 years?
Keels fall off for other reasons
the recent loss, the keel flange and all bolts were still attached to the hull and in good order.
Of course keel loss may not occur but the boat still sink because of uncontrollable water egress though keel bolt holes when the keel has moved as bolts have broken.
There is some evidence that a sinking in an Australian race a few years back was caused in this way. all seacocks and hatches closed and no evidence of a breach of the hull skin yet water flooding in so that source could not be isolated.
As to the last part a lot will depend on use, but yes.
Bash upwind a good sea for 50 miles and see what you think.
The high profile losses have generally been VLCG keels but every time I read about a boat sinking and the point of water ingress could not be found I think keels bolts or keel movement now.
So that is different issue to a keel fin breaking off but no less problematic.
Select to expand quotelydia said..r13 said..lydia said..
Again a big rap for the lads at R & M Marine at Kettering, especially Dunc, old school boat builders with attention to detail.
Others would not know what silicon bronze even was or were to get it.
At a different level, on Friday I was asked by the head of safety at Aust Sailing if i would send a zip file of all the photos to the head of the World Sailing Technical Committee who is doing a review of the keel bolt replacement issue.
Well done. New version of the ISO code coming in 2025 apparently............
www.researchgate.net/publication/379120751_Regulatory_Developments_in_Structural_Keel_Design_A_Revised_ISO_12215-9
Who happens to be an author of that paper!
Righto I get it...............not me.............
AS article
www.sailingresources.org.au/news/keel-inspections
Good article here
www.sailmagazine.com/diy/how-secure-is-your-keel
L why don't you suggest to World Sailing that they take your best and worst old keel bolts and have them ultrasonically tested by highly experienced NDT techs and companies globally, so that potentially an ISO standard on NDT of yacht keel bolts can be compiled using calibrated test data. Hopefully they are doing this right now with stuffed keel bolts coming out of yachts globally on a weekly or daily basis. Just a thought. My understanding is that such UT testing is being done globally on the slips and in the water right now, but it is an emerging field and not ready for such a standard to be compiled. Hopefully such a standard being finished and published is imminent. Good article here
www.ndt.net/events/APCNDT2017/app/content/Paper/13_Grosser.pdf
I've pulled a couple of studs out of an S&S 34 keel (3/4" 316 stainless) and they looked like new after 40 years. But it's horses for courses obviously, you don't reallly know they're fine until you get them out. I guess one simple method to tell if a bolt is completely stuffed is to tighten it to spec with a torque wrench, and if it breaks then it's obviously buggered. But that only tells a partial story.
