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Deleted User YDKXO
Guest
Yup thats what I think and I do wonder whether I'm opening a can of worms by having the windows changed in that if the bonding is not done properly, changing the windows could be a regular occurence
Yup thats what I think and I do wonder whether I'm opening a can of worms by having the windows changed in that if the bonding is not done properly, changing the windows could be a regular occurence
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Deleted User YDKXO
Guest
Yup it is squashed in tight at Antibes but the cracks started before I got to Antibes so that isnt the reason. Btw the reason that I'm squashed in so tight is because the bloke next door in his Sq78 has got his pasarelle in the wrong place
Re your other comment about other manufacturers having spare windows lined up in La Rague I do wonder whether with this trend towards ever bigger hull windows, there will be increasing numbers of owners fuming over cracked windows
MapisM
Well-Known Member
Now, this is a good Q indeed.
I'd be very tempted to reply "nothing", if I didn't fear your request to refund a sank boat...
MapisM
Well-Known Member
Well, I already said in the past that as nice as it can be to have a sea view also from the cabin, in a boat I'd rather stay in the saloon, or even better outside, to fully enjoy the landscape.
And in a thread like this, I can only rest my case, of course.
That said, I'm not sure that the windows per se are to blame for cracks.
I've looked in detail at quite a few boats lately, built in a pretty wide range of years (early 90s to mid naughties), and from several different builders.
But with all of them, bar none, I got the impression that the hull construction has progressively been lightened.
Which btw is understandable for planing boats, where weight is an enemy to fight - though it would be difficult to blame someone for suspecting that also cost cutting had something to see with that...
Anyway, while lighter construction doesn't necessarily mean that newer hulls are going to fall apart in heavy seas, it's reasonable to guess that they flex more than older hulls did - which in turn can take a toll on any bonded large glasses.
In fact, I've also seen a couple of relatively new boats (about 10yo) with cracked windshields, while I've never seen (nor heard) of that happening on 20+yo boats...
AllanG
Well-Known Member
Mike, can you confirm that both the port and starboard windows are cracked, or is it just one side? Also, if both are cracked, are the cracks in different longitudinal positions within the glass, or similar positions? Is it just the one window that is showing signs of a possible bonding issue on the lower edge?
In my view, if you just left the crack(s), I think, over time, they would increase in length due to movement of the boat, which is similar to a cracked car windscreen. However, the risk is that as the internal structure of the glass has been compromised, any excessive external force on the glass may suddenly lead to a total failure, which is not a situation I'm sure you'd like to be in.
Another point, which I'm sure you've considered, is how your insurer's would react to a possible failure of the glass after you have already discussed these cracks with them, but took no action to replace them?
petem
Well-Known Member
Considering we're in Feb now, I think the best course of action would be to order the new windows now (I suspect they could easily take three or four months to be made and fitted) and get a surveyor to provide a report giving the root course and also confirmation that the boat is seaworthy. You can argue about who pays for the replacement at your leisure. The important things are to ensure the boat is safe and useable for the summer.
Nick_H
Well-Known Member
It seems to me that you need to find out why it happened, so you're not facing the same bill again.
I agree the best theory so far is that the bonding has weakened along the bottom edge which has caused the glass to experience stresses that it isn't subject to in the fully bonded state, but that is only a theory. Other things to consider, have you lifted with full tanks and where are the tanks in relation to the lifting strops? Do you fender off near the windows which may cause lateral deflection of the glass or surrounding GRP? You say the bonding seems to be failing, but there's no water ingress, could it be the bonding between the laminations that has failed, rather than the glass to frame bond?
I think you either need a glass expert or suitably experienced surveyor to have a look, or could you send photos to Ferretti / San Lorenzo for their opinion?
I agree the best theory so far is that the bonding has weakened along the bottom edge which has caused the glass to experience stresses that it isn't subject to in the fully bonded state, but that is only a theory. Other things to consider, have you lifted with full tanks and where are the tanks in relation to the lifting strops? Do you fender off near the windows which may cause lateral deflection of the glass or surrounding GRP? You say the bonding seems to be failing, but there's no water ingress, could it be the bonding between the laminations that has failed, rather than the glass to frame bond?
I think you either need a glass expert or suitably experienced surveyor to have a look, or could you send photos to Ferretti / San Lorenzo for their opinion?
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Deleted User YDKXO
Guest
Thanks Nick. Here is a pic of the boat being launched in Mar 2015. The fuel tank (single tank - 3700L capacity) is located at the forward end of the engine room and the aft strops are pretty much directly under the fuel tank. For that reason I can't see that the amount of fuel in the tank would make any difference to load distribution on the hull
The boat was lifted at the same yard last winter and the pic I have shows it slung in the exact same way
Well like everyone I guess we have fenders equally spaced on both sides but at gunwhale level well above the windows. The mooring we had in Carloforte until July last year had plenty of space anyway so I don't believe that pressure from other boats was an issue
Yup that is a very good point but I'm not qualified to say
I think you're right. At the very least before I embark on an expensive window replacement exercise I need to try to understand the failure mechanism. I have already sent the photos to Ferretti and they have blamed incorrect lifting or use in a heavy sea (never mind that Ferrettis are all Cat A and supposed to be capable of taking a heavy sea). I will contact Jim Pritchard who did the original survey and see if he is willing to inspect the boat and do a report. At least I will have something official to throw at either Ferretti or my insurance co
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Deleted User YDKXO
Guest
Yup youre right and thats what I'm going to do
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Deleted User YDKXO
Guest
AllanG the windows are cracked on both sides in similar ways (ie bottom up) and both windows are showing signs of bond failure at the bottom edge. It is odd that both windows have failed at the same time in the same way though
Yup fair point but my insurer has already refused the claim. The windows are a couple of feet above the waterline but of course if there was a catastrophic failure in a heavy sea then the insurers may well refuse any claim for interior water damage also
AllanG
Well-Known Member
Having a similar failure on both windows is very odd and, in my view, points to a manufacturing, installation or design fault, and I'd certainly be looking to the builder for help to rectify the faults.
Portofino
Well-Known Member
I did not pick up on both sides more /less same time ,I read "July " last year .Thought it was just a one off.
Presume boat has not been lifted in summer 16 ,and Mike cannot recall any big sea ,s to speak of ?
Just seems odd to me to factor in the strength of the glass via bonding in hull torsonal stiffness .
I was under the impression (rightly or wrongly ?) that with gaping holes in the hull sides either broadly rectangles like this Ferretti or slashes like some of the latest Sunseekers ,were framed in carbon fibre or maybe Aluminium or both .
This extra frame which is glassed /bonded in to the rest of the hull takes ,distributes and deals with all the hull flexing .
The laminated glass just sits nicely bonded into the frame immune from movement as far as glass needs to be before it fractures ..
How ever if this modern trend is simply cut a hole any shape and glue in a corresponding piece of laminated glass using "wonder bond " or what ever it is ,and expect the glass to take over structurally from what would have been normal plastic /GRP /lay up ,then the hull flexing will pop the bond ,glass is stiffer than the plastic /GRP .
Or the glass #
The two materials have hugely different modulus of elasticity and should be seperated from each other( via a frame ) ,not bonded to each other .
So for the glass to # ,the bond ,"wonder bond " has NOT failed ,the # force has been transmitted to the glass ,excess force ,cos something else in the plastic /grp side has failed .
If the "wonder bond " failed ,then it would leak -it doesn,t and the glass would NOT get the full force from the flex ,cos it's popped out so to speak ---- there will be no crack , just a leak !
Bilateral and vertually simultaneous ( now found out ) means the hull is indeed flexing .
Why now ?
Something else has failed ---deeper in the hull , weakening it and the fully bonded glass cannot take the extra strain ,hence the # -that's what you have here
Without knowing the construction details , it's difficult to know ,but there's a latent defect that's weakened the hull .
So a competent surveyor is as said above now looking like a good idea .
I getting a feeling this is not going to be a happy ending .
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rafiki_
Well-Known Member
I wouldn't be quite so concerned about the principals of bonding glass. This is nothing new, the auto industry having been down this route for 30 odd years. The industry went this way with the introduction of airbags, which require the windscreen to remain intact and in place, to take the load of the bag as it deploys. With old style seals, the glass just pops out, and the airbag can't do its stuff. The auto industry probably has a better record with FEA in order to understand all the forces, and driving dynamics, and cars will impart higher shock loads into the bodyshell sometimes up to 50 or so g, and the screen and bonds remain intact. Anyway, this is drifting a bit, but my point is, that bonded screens are well understood with regards to load, stress and strain.
I believe the glass in Mike's Ferretti has a polycarbonate laminate, and given that the fritting in Mikes glass is intact, it looks like the polycarb has cracked. Polycarbonate is not the best material for this application, so we could be looking at a manufacturing or batch issue. Mike really needs someone who knows their glass onions to have a look, and give a professional opinion.
jfm
Well-Known Member
FWIW, on the glass and auto comparison: in cars as Rafiki says the glass is structural and the front and back glass is a substantial part of the car body construction. The adhesive used is therefore thin and stiff. Car manufacturers can build and crash 50 prototypes if they want, to get the design perfect.
With a boat you cannot crash prototypes so the hulls are generally designed to be strong enough without the glass. Lotd of corner reinforcing, etc, as porto says. The glass just seals the hole. Accordingly, the adhesives used are flexible and absolutely must be applied thickly to give enough glue material to allow a few mm of flex. If not, the bond fails, due to the different stiffness of glass and the hull, as porto says.
For this reason you wouldn't want a car windscreen guy to fit boat glass using his car techniques and materials.
IF the glue was applied too thinly then the impact of hull on waves would tend to overload the glass and also split the adhesive bond. But Ferretti surely wouldn't get that wrong. There are loads of other possible causes.
As regards going back and demanding a repair from Ferretti, as suggested above, that doesn't fly as Deleted User has no contract with Ferretti aiui. Alas in this case I think the only feasible solution is to get the spares from Ferretti and have a boat glazing expert install the new glass using recognised grp-glass adhesive like saba 760xl (with the correct primer) or whatever is the latest recommended product (worth asking ferretti for the product and install spec/ thickness)
With a boat you cannot crash prototypes so the hulls are generally designed to be strong enough without the glass. Lotd of corner reinforcing, etc, as porto says. The glass just seals the hole. Accordingly, the adhesives used are flexible and absolutely must be applied thickly to give enough glue material to allow a few mm of flex. If not, the bond fails, due to the different stiffness of glass and the hull, as porto says.
For this reason you wouldn't want a car windscreen guy to fit boat glass using his car techniques and materials.
IF the glue was applied too thinly then the impact of hull on waves would tend to overload the glass and also split the adhesive bond. But Ferretti surely wouldn't get that wrong. There are loads of other possible causes.
As regards going back and demanding a repair from Ferretti, as suggested above, that doesn't fly as Deleted User has no contract with Ferretti aiui. Alas in this case I think the only feasible solution is to get the spares from Ferretti and have a boat glazing expert install the new glass using recognised grp-glass adhesive like saba 760xl (with the correct primer) or whatever is the latest recommended product (worth asking ferretti for the product and install spec/ thickness)
KINGFISHER 9
Well-Known Member
Y Insurance say 'latent manufacturing defect' ... have they been and looked at it? Maybe you can get a surveyor to tell them it's damage ... what will they say then?
Bandit
Well-Known Member
Can you feel a crack at all inside or out with your fingernail? Pehaps if its in the outer layer dye penetrant would show it?
My feeling would be to appoint a good structural surveyor to look at your boat and the windows in particular but the whole of the structure in that area to see if there are any failures that could unduly stress the windows. The surveyor would then let you have a report which you may choose to submit to the manufacturer at a later date.
Normally with laminated windows its two layers of toughened glass on the outsides with a soft material (not rigid) on the inside which is there to hold the glass pieces in place in case the outer or inner layer shatter.
I would be looking for an irregular gap between the hull moulding ie the frame and the glass where with a slight movement a pressure may be exerted onto the glass by displacing the sealant. I assume there should be a uniform gap of say 10mm which is filled by sealant bed.
My feeling is that there is a cat in hells chance of getting replacement glass from anyone other than Ferretti that would match and fit, only Ferretti know the shape of the glass, colour and spec let alone the glass manufacturer and that the time from order to receipt of the glass is months not weeks say 3 months?
Once the surveyor is complete I would contact Ferretti with a copy of the report and ask them how they can replace the glass and ensure that the problem would not arise again. I would try and get the boat booked in to have the work done by Ferretti in Say October when the replacement glass is to hand and ask them for a sensible price to do the work.
My feeling would be to appoint a good structural surveyor to look at your boat and the windows in particular but the whole of the structure in that area to see if there are any failures that could unduly stress the windows. The surveyor would then let you have a report which you may choose to submit to the manufacturer at a later date.
Normally with laminated windows its two layers of toughened glass on the outsides with a soft material (not rigid) on the inside which is there to hold the glass pieces in place in case the outer or inner layer shatter.
I would be looking for an irregular gap between the hull moulding ie the frame and the glass where with a slight movement a pressure may be exerted onto the glass by displacing the sealant. I assume there should be a uniform gap of say 10mm which is filled by sealant bed.
My feeling is that there is a cat in hells chance of getting replacement glass from anyone other than Ferretti that would match and fit, only Ferretti know the shape of the glass, colour and spec let alone the glass manufacturer and that the time from order to receipt of the glass is months not weeks say 3 months?
Once the surveyor is complete I would contact Ferretti with a copy of the report and ask them how they can replace the glass and ensure that the problem would not arise again. I would try and get the boat booked in to have the work done by Ferretti in Say October when the replacement glass is to hand and ask them for a sensible price to do the work.
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henryf
Well-Known Member
I would try to be there camera in hand when they remove the glass to see if there is any obvious reason for the cracking once you can see all the exposed areas.
The most common cause of glass cracking is a point load somewhere, a stone for example. A high point or rib about which the boat moves, even a manufacturing defect on the edge of the glass which has finally given up the ghost.
If the bonding has failed then that area would be likely to crack as the glass is supporting all the movement rather than the glass being supported by the hull. The sandwich of glass, bonding material and hull will be stronger than just the glass.
I hope you manage to find a sensible resolution here and agree we are likely to see more examples of this in the future.
I'm keeeping an eye out to see how Ferretti respond. It's hard to see how this can be anything other than a manufacture defect and people investing large sums in current new boats need confidence that they won't be in your shoes. You can't just sweep the problem away by saying our new boats are better. We are constantly being told of new technologies employed so I would want to know a boat builder stood by their product. If not I would buy elsewhere.
If Ferretti profit from this it shows they have no concern at all about the long term quality of their product. Make it good enough to get get it out of the factory gates then sod 'em. If it's a supplier issue not an assembly issue then lean on that supplier who will most likely still be supplying the factory.
Henry.
The most common cause of glass cracking is a point load somewhere, a stone for example. A high point or rib about which the boat moves, even a manufacturing defect on the edge of the glass which has finally given up the ghost.
If the bonding has failed then that area would be likely to crack as the glass is supporting all the movement rather than the glass being supported by the hull. The sandwich of glass, bonding material and hull will be stronger than just the glass.
I hope you manage to find a sensible resolution here and agree we are likely to see more examples of this in the future.
I'm keeeping an eye out to see how Ferretti respond. It's hard to see how this can be anything other than a manufacture defect and people investing large sums in current new boats need confidence that they won't be in your shoes. You can't just sweep the problem away by saying our new boats are better. We are constantly being told of new technologies employed so I would want to know a boat builder stood by their product. If not I would buy elsewhere.
If Ferretti profit from this it shows they have no concern at all about the long term quality of their product. Make it good enough to get get it out of the factory gates then sod 'em. If it's a supplier issue not an assembly issue then lean on that supplier who will most likely still be supplying the factory.
Henry.
petem
Well-Known Member
But what happens if the crack get a lot worse in say May and the boat becomes un-seaworthy. Waiting three of four months for a replacement could write off the whole summer. At least get an idea from Ferretti how long it would take to get the glass.
rafiki_
Well-Known Member
Not these days JFM, nearly all done on the tube, with a couple of cars crashed for verification. We used to have book 18 months ahead to get a crash at Mira or Millbrook. The halls are empty these days. However your gist is right, the effort that goes into vehicle design is many magnitudes more than boat hulls.
One of the problems with the bonding gue, is that it stiffens with age, and can crack. However you are likely to pick this up through leaks.
Portofino
Well-Known Member
Thanks Nick. Here is a pic of the boat being launched in Mar 2015. The fuel tank (single tank - 3700L capacity) is located at the forward end of the engine room and the aft strops are pretty much directly under the fuel tank. For that reason I can't see that the amount of fuel in the tank would make any difference to load distribution on the hull
I will contact Jim Pritchard who did the original survey and see if he is willing to inspect the boat and do a report. At least I will have something official to throw at either Ferretti or my insurance co
I would hesitate "throwing " anything at Ferretti until the last blocking off has been investigated .
Have you got a pic to answer Ferretti,s and poss Jim Pritchards question --"-was it blocked off correctly "-last time out ?
Any internal damage (out of sight ) to the integrity of the hull re torsional stiffness ,could have come from what Ferretti could argue -and -"throw back " - incorrect blocking off by the yard ,
Which later in the season 2016 manifested in a bit more hull flex ,not a lot ,but enough to exceed the thick bond cushion ( which was protecting the glass being stiffer than the surrounding plastic /GRP ) .
Full tanks and poor blocking off might be the reason --- why now ?
Full tanks are not the reason per se ,just the extra weight exacerbates wrong forces in the wrong place at wrong time because the blocks supporting the boat where in the wrong place .
It's not just the position either ,I think the blocks should be the same material .
All metal cages with the same thickness of the same wood pads on the keel area .
For example in a 3 point support ,if the outer are metal cages -one near the stern gear and the other near est the bow ,if the middle under the mid cabin is just wood ,then the the mid support may sag slowly in the next few days .Unkowningly the boat ( unsupported by water ) is now bending like a banana .
Being observant in my yard they are very finicky on this ,each bay has a set of metal cages lined up before the boat arrives after its lift -and they are real fussey on siting them and lowering the boat, resting its keel on them , often making what seems time consuming adjustments before finally settling it down .Same applies when they pick it up -slow job lifting it off the blocks .Seem to be reffering to strain guages all the time .
So for me while the pic above shows the correct position ,it does not tell the strain on each end at touch down / lift off -that's also potentially damaging in my book .
So I wonder from any yards perspective if they have ever been involved in a blame game-bending boats ?
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