Cracked hull windows. Any advice?

[benjenbav]

You certainly cant be much worse off unless it shatters.

There's cheerful, J...

 

[jrudge]

Not really

Its the skip or a repair so there is nil downside to trying

There's cheerful, J...

 

[jimmy_the_builder]

Not really

Its the skip or a repair so there is nil downside to trying

Except that you've got to buy the replacement glass anyway, in case the repair attempt doesn't work - but if the repair *does* work, then you're long by a very expensive boat window.

 

[bigwow]

Is it worth getting a car windscreen repairer to see if he can effect a repair, even if it's a temporary measure.

 

[Deleted User YDKXO]

Twenty years of teaching fracture mechanics to undergraduate engineers.

Thanks for the analysis JumbleDuck. Excellent idea for the stress relieving hole. Did you mean 4mm in?

 

[Deleted User YDKXO]

like saba 760xl

jfm when you say this is the 'latest and greatest' are you saying this is what boatbuilders are using now or is this a glue from outside the industry? How difficult is it to control and apply? In other words can any competent boatyard work with it?

Is it likely to be more flexible than the glue Ferretti would have used 10yrs ago? So even if I get a similar kind of hull flexing as might have caused the original glass to fail, this glue would take up some of that movement?

 

[Deleted User YDKXO]

In a couple of occasions, with cracked car windshields, I did experience such feeling.

Yup I have a crack in my laminated car windscreen right now and I can feel it with my finger in a way I can't feel the crack in the boat window. Doesn't mean much but could indicate the crack is internal

 

[Deleted User YDKXO]

I'm resurrecting this thread really as a warning to any boat owners out there with bonded windows like mine. I asked a yard with experience on Ferretti boats to check out the windows on my boat. The good news is that they think the windows on my boat will last another season without replacement so I'm going to leave replacing my windows until next winter especially as delivery of new windows is possibly upto 15 weeks

What is worrying is that the yard told me that they are seeing similar faults on other boats now and not just Ferrettis

This is an Azimut

and this a Pershing

FWIW the yard reckons this is a temperature related problem rather than a structural one. Maybe that suggests that the problem could be more prevalent in the Med than N European waters. Whatever the truth anyone contemplating buying a boat with bonded windows should have the windows thoroughly checked by a surveyor and anyone owning a boat with bonded windows should keep an eye on them

 

[jfm]

Mike, thanks for update. The azimut and pershing problems look like failure of the glue bonding rather than cracking of the glass, right? That shouldn't happen, but of course it is happening, so you're right that people need to look out for it.

Several manufacturers now make the glue and the technology has been in cars for years. It's a pity that there isn't easily available data on the performance of the different glues.

I don't buy the theory of your yard that it is temp related- cars parked in the sun get hotter for longer than boats. I think it is more likely to be a combo of poor application techniques and differential flexing of the grp hull and the sheet of glass.

 

[Bouba]

Mike, thanks for update. The azimut and pershing problems look like failure of the glue bonding rather than cracking of the glass, right? That shouldn't happen, but of course it is happening, so you're right that people need to look out for it.

Several manufacturers now make the glue and the technology has been in cars for years. It's a pity that there isn't easily available data on the performance of the different glues.

I don't buy the theory of your yard that it is temp related- cars parked in the sun get hotter for longer than boats. I think it is more likely to be a combo of poor application techniques and differential flexing of the grp hull and the sheet of glass.

Yes, I would be more interested in how GM bond the glass to Corvettes

 

[Deleted User YDKXO]

Mike, thanks for update. The azimut and pershing problems look like failure of the glue bonding rather than cracking of the glass, right?

Yes thats correct but I believe thats how the problems with my windows started. In other words the bonding started to fail in a few places first which then caused the window itself to start to delaminate and cause the cracks (which the yard agrees are internal, not in the glass)

Yup I tend to agree with you on the cause. I believe that my Ferretti was one of the first they produced with bonded windows and probably their understanding of the technique was not as good as it is now and maybe neither was the glue they used either. I believe I'm right in thinking that the Italian yards were earlier adopters of the technique than British yards which could explain why the problems seem to be with Italian boats at present unless somebody can tell me different

 

[MapisM]

The Pershing pic suggests that the problem potentially involves any bonded glasses, not just hull windows - which stands to reason.
In fact, in terms of sun exposure and thermal excursions (assuming that this is the critical factor), upper windows are bound to be even worse than hull windows.
I'm rather glad to have always liked the look of the good old stainless steel frames, and have zero bonded glasses also on the DP (possibly one of the very latest boats without them, back in 2004)...

 

[Deleted User YDKXO]

I'm rather glad to have always liked the look of the good old stainless steel frames, and have zero bonded glasses also on the DP (possibly one of the very latest boats without them, back in 2004)...

Even those were not without problems. Some manufacturers such as Princess used to fit window frames which consisted an aluminium inner structure and a stainless outer covering which resulted in corrosion of the aluminium parts and white powder appearing at the bottom of the windows. Probably as expensive a fix as repairing bonded windows

 

[MapisM]

Urgh, that goes straight in the list of things to check with Mr.DP...
Though I suppose (/hope) that there's no alu inside my s/s frames, 'cause the problem would have surfaced by now, while they look as good as new instead - touch wood!

 

[Deleted User YDKXO]

Urgh, that goes straight in the list of things to check with Mr.DP...
Though I suppose (/hope) that there's no alu inside my s/s frames, 'cause the problem would have surfaced by now, while they look as good as new instead - touch wood!

You would definitely have seen the problem by now so you wont have any worries

 

[jfm]

Yep, I would say that alu/ss combo is a Princess cost-save special. Plenty of yachts, built in IT and other countries, are built with ss (only) frames to the windows/portholes, and I'll bet $100 that DP windows are ss with no ali

Of course, ss frames still rely on polyurethane sealant. Not to same extent as or in the same way as bonded windows, and the glue is perhaps less exposed to UV light, but if the glue decays with age then the boat will still need work. No big deal - all boats need work anyway!

 

[MapisM]

I'll bet $100 that DP windows are ss with no ali

I'm not betting against you, 'cause I'd loose.
Already checked and confirmed (onboard as I'm writing, to follow several other things): it's s/s only.

All agreed on the rest, particularly your last sentence...!
Though there's something worse than dealing with the work that one boat needs: dealing with TWO of them, that is...
If I should also bet on something, my $100 are on the fact that SD agrees with me.
Apropos, how's things on the Aq74?

 

[Deleted User YDKXO]

Apropos, how's things on the Aq74?

We saw her in Villefranche the other day. Very fine looking vessel. Even the SWMBO said whats that and she has about as much interest in boats as I have in dishwashers

 

[MapisM]

LOL, sounds like you can stop thinking about what boat you might choose as your next one, M!

 

[Deleted User YDKXO]

LOL, sounds like you can stop thinking about what boat you might choose as your next one, M!

You know who wears the trousers in the Deleted User household