Keel cracks

BristolDiver

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Viewed a yacht on the hard, 20 years old, hull looks fair & generally all in vgc inside & out - however can't ignore what looks like a substantial crack (or repaired crack) on the leading edge of the keel. Hull all around keel, again looks fair with no bulging or cracking. Survey will of course follow, but is this an absolute deal breaker?

keelcrack.jpg
 
It looks like a crack, although there is a faint possibility that it is a mould defect that has been there since new. Inspection of keelbolt location would help, it may be that the fragment that appears to be broken off plays a very small part in securing the keel to the hull.

It seems this a question best addressed to the owner. There may be a satisfactory explanation.
 
Yes. Whether a mould defect or a crack, its still a defect and it weakens the keel in a key area.

Lift boat - drop keel - grit blast - weld to repair - coat - re-install. Maybe £7/8k at an outright guess.

If you do go ahead, examine the hull round the keel with care. Its very unlikely that that level of damage (if that is what it is) could occurr without a bad grounding.
 
Well something has been going on there for certain. Personally I would want to remove all antifoul and examine the hull carefully. If that is free of cracks then it's a matter of dropping the keel and examining carefully. There is probably nothing that cant be welded and repaired easily as it looks forward of keel bolts and therefore not structural. This however makes it even more of a puzzle. How did it crack there?? Either way you have a reason to negotiate a substantial reduction in price and I would not proceed further without a credible explanation from the present owner and a detailed survey which cannot be done without removing all paint and antifoul first which the owner needs to agree to.
 
It's not an area of metallurgy that I'm fully familiar with, so I'm ready to be corrected. Weld repairs of grey cast iron, which I assume this is, range from difficult to impossible. Considerable pre-heat and post-weld heat treatment (of most of the keel) would be required, plus a very skilled welder. It could well be cheaper to have a new keel cast.

Stitch repairs are possible but again this won't come cheap.

Best bet seems to be that this fragment does not do very much and maybe the situation has been like this for a long time. If the uncertainty is reflected in the price, and with sufficient technical input, the boat could be a worthwhile purchase.
 
it looks forward of keel bolts and therefore not structural. This however makes it even more of a puzzle. How did it crack there?? .

Agreed. How long has it been like this? What caused it? Drop from a crane onto forefoot of keel? If the bit forward of the keelbolts is not bolted, I'm surprised it hasn't come away or even fallen off.
 
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Agreed. How long has it been like this? What caused it? Drop from a crane onto forefoot of keel? If the bit forward of the keelbolts is not bolted, I'm surprised it hasn't come away or even fallen off.

The very questions I'm going to have to put forward. I didn't get access to the front keel bolts, but got photos of two of the rear ones which showed some evidence that they had been disturbed, but looks like a long time ago - well painted over and protected. I think last change of ownership was 6-8 years ago, and looks as though certainly hasn't been disturbed in that time. No obvious evidence of deformation or cracking in the structural members around those bolts. Now you mention it, I did come away with some suspiscion of a former crane accident when looking at the keel, but I really don't know what I'm looking for. Will post another photo later when I get home, but for me the bottom few inches of the leading edge of the keel seemed to have a slight wrinkle in it, this boat may have a lead shoe on an iron keel if that makes a difference?

The hull fore and aft of the keel was perfectly fair and smooth, with little evidence of thick layers of antifoul that could hide any nasties. If the keel really sustained significant damage, would the hull integrity not have been compromised :confused:
 
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the bottom few inches of the leading edge of the keel seemed to have a slight wrinkle in it, this boat may have a lead shoe on an iron keel if that makes a difference?

The hull fore and aft of the keel was perfectly fair and smooth, with little evidence of thick layers of antifoul that could hide any nasties. If the keel really sustained significant damage, would the hull integrity not have been compromised :confused:

Cast iron is both porous and - depending upon casting quality - prone to weak areas, and can shatter. So I suppose it's possible that a drop onto concrete by a crane could cause the shock to travel up the leading edge and cause the crack at a weak point at the top. However, I would have thought that a lead shoe would deform and act as a shock absorber.

Another thought: is there a mast heel or mast compression post located at, or close to, the 'broken bit' of keel? (Think 'Piledriver' :eek:)
 
Cast iron is both porous and - depending upon casting quality - prone to weak areas, and can shatter. So I suppose it's possible that a drop onto concrete by a crane could cause the shock to travel up the leading edge and cause the crack at a weak point at the top. However, I would have thought that a lead shoe would deform and act as a shock absorber.

Another thought: is there a mast heel or mast compression post located at, or close to, the 'broken bit' of keel? (Think 'Piledriver' :eek:)

Mast compression post would be right about there.... :(
 
Best bet seems to be that this fragment does not do very much and maybe the situation has been like this for a long time. If the uncertainty is reflected in the price, and with sufficient technical input, the boat could be a worthwhile purchase.
If is IS considered structural you could drop the keel and insert a 1/4" steel plate cut to the shape if the keel stub and drilled to take the bolts.
 
It Very Much Looks Like Impact Damage From Hitting A Submerged Object

This is a bit of a flash back. I was involved with a Sigma 41 which motored over a rock. Keel stepped mast. The impact on the front edge pushed the keel up into the boat and pulled the rear bolts down into the hull causing both stringers at the front and back of the keel to crack.

The front portion of the flange was bent down and torn open (surface between top of flange and hull) but not separated. The keel was scrapped and a new one fitted.

I have some experience of accepting cast or forged products (large pressure vessels) and this type of defect would not be acceptable to the buyer or to the foundry. There are fairly defined standards for structural castings. So I very much doubt that a modern boat builder would accept such a keel from their supplier. You can probably ignore in confidence that this is a manufacturing defect.

The Sigma 41 was rebuilt, stringers repaired and doubled up below. The boat was much stiffer and raced better but the woodworked creaked like mad and nothing quite fitted together again.

Check the front of the keel for signs of repair. It may have been faired very well and this can be a clue. If the rest of the keel has a bit of roughness and the front edge is quite smooth relatively to the rest of the keel, you may be looking at a repair.

Check the furniture inside, has it been removed? Check to see if the stringers have been repaired? To snap or bend this flange takes a lot of force. If the boat has been damaged and you can not determine if it has been repaired correctly then walk away from it. A repair like this should have obvious history unless there is something to hide.
 
More images - can't see a repair so getting nervous

Couldn't get access to forward keel bolts - table in way and floor screwed down in that area on this model of boat, but the rear ones looked ok to my untrained eye, with no sign of movement or distortion.
keel_bolts.jpg


This is the 'wrinkle' on the tip of the keel - no other obvious damage at all.....
keel_tip.jpg


Would I be wasting my money in commissioning a survey? The broker claims ready to sail away and priced as such (though not yet tackled this issue).
 
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Hmm...

Tip of keel looks like it's hit something...

Top of keel looks like it's broken due to hitting something...

Floor / stringer joint looks like it's had a splodge of CSM over it where it would be likely to crack if the keel hit something... (and it looks like it's been painted, whereas the rest looks flow-coated)

Would I be wasting my money in commissioning a survey? ...

That's for you to decide.

I concur with Vyv et al regarding the feasibility / effectiveness of trying to weld the keel. I wouldn't discount it as 'non-structural, either.

Unless there's something really special about the boat, I would move on.

0.02p

Andy
 
Compass, sitting a couple of inches from a cast iron keel?

Even I noticed that one! I can't think of a worse place I've ever seen a compass unit... :(

I'd want to have a look around the trailling edge of the keel both inside and out, as well as the front of the keel bolts. look for cracks around the back end, and around the stringers...IF she has hit something and it's pulled the front end down causing the crack it's also likely to have pushed the back end up.

If you can't see the bolts, stick your digital camera under the floor and take a few pics....Hold your finger vertically where you think the bolt should be, press the shutter 1/2 way down so the camera focuses on your finger then move the camera vertically downwards so the focal point is the same distance from the camera, and take a pic or two. until you get a good picture.

If you have a compact the depth of field should be alright to get an idea.

If you are serious about buying and you get a survey, ask the owner to fully remove the floorboards prior to the survey. The surveyor can only survey what they can see, they won't remove any screwed panels...if you think about surveying a wooden boat where would they stop?? :)
 
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I think that you already have justified concerns about this boat.
I would too. I am not a surveyor but for me, just my opinion, from what we can see from the pictures, plus the layers of the paint/mastic/gobbo or what ever you want to call it around the floor stringers, I would say walk away. Save the survey fee for later.

When I was looking for my boat, my first criterior was it needed to look good to me withouth needing a surveyor to point out the obvious. Any boat that gave me obvious concerns was struck off the list. When I found a good one, then I had the survey, I wanted his expert eyes to look for what I could/did not see.

Must add that on a 20 yr old boat such as the one that you are looking at, there is obvioulsy the chance that it has suffered damage over the years. Damage can be repaired, and if done so properly should not be a problem. But to my eyes this would be one I would have walked away from.
 
With a crack like that and no related grp damage to the surrounding hull I would say the keel has been dropped or damaged in some way while off the boat.
If there are no bolts or studs in the small peice then it is likely there should not be any problems apart from cosmetic, which could be covered over with filler.

A wee change of thought here, could it be possible that the boat was supported on shores and that excessive weight could have been placed on a transverse shoring plank placed under the broken peice of keel.
The broken peice must have studs in it or it would be off by now.
Looking at some of the interior pics, especially the one with the gas alarm sensor or what ever it is, there is a crack in the rib/ cross floor, above and to the right of the sensor, this does not look good.
Personnaly if it was my boat I would have the keel off for further investigation, which I have done in the past with my present boat and now feel very confident about the keel security/integrety.
Contrary to what some other posters say, I would have thought that if the lower forefoot of the keel was hit while in forward motion it would pull down the front top area of keel ( tensile load) and push up the aft upper area (compression) which is also likely to cause a break like that as the studs/bolts in the small peice and the grp hull that those studs/bolts passed through would probably have more combined strength than the area of cast at the crack.
These are possabilities of the cause.
Btw would this happen to be a Sigma33?
C_W
 
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Viewed a yacht on the hard, 20 years old, hull looks fair & generally all in vgc inside & out - however can't ignore what looks like a substantial crack (or repaired crack) on the leading edge of the keel. Hull all around keel, again looks fair with no bulging or cracking. Survey will of course follow, but is this an absolute deal breaker?

Based on your second picture, I wouldn't be terribly worried about the crack affecting the strength of the keel. It looks a lot worse in the first picture, but in the second it's clear that it only affects a tiny proportion - maybe 10% - of the top flange. Think of it this way: would you be concerned if you saw another yacht with a keel design which was identical save that it was truncated where the crack was? I certainly wouldn't.

However ... I would very definitely want to know how the crack happened, because, as others have said very eloquently, whatever did that to the keel may have done other nasty things to the hull. Or it may not - a smallish flange like the front might be quite easy to snap off by tightening the keel bolts in the wrong order.

Whatever the explanation is, get it verified by a surveyor who knows these boats well. This certainly wouldn't be a deal-breaker for me - at least you can see that something needs checked and check it.
 
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