Cat A ocean standard need full revision

[Concerto]

I know a 29ft Westerly Konsort crossed the Atlantic with a crew of 3, but shipped the boat back. Geem's comment about the return journey across the Atlantic is from his personal experience and talking with other ocean cruisers.

Having had a long discussion with Tranona on new boats compared to old boats on this forum. I met him when I had Concerto at the Boat Show in 2021, where he complimented me in discussing the difference in a civilized way. At the time he still had his Bavaria 33, but I feel I eventually won the argument as he changed his boat and bought an old boat (IIRC it's a Golden Hind). I have met him since and get on well together. He is very knowledgeable on lots of the technicalities of boats as he used to lecture on this subject. He does not have the ocean experience of geem, nor do I. I have not met geem, but do agree with both of them on many points in this discussion.

My position remains that large hull windows are a long term risk that we still do not know how long the bonding will last. Any loss of a window may show as a leak prior to total failure, but over what time scale does this happen or is it just a matter of minutes. Any breach of the hull is dangerous, but large windows in the hull is a risk I would never take. We may never know about all window failures as the boat is likely to sink quickly in rough weather and most likely total loss of the crew.

 

[lustyd]

we still do not know how long the bonding will last

We know it lasts the rated 10 years. Anything beyond that is irrelevant and pure luck. I’m sure impellers last more than a year but I change it anyway because that’s the service schedule.

 

[geem]

Which manufacturers say replace the sealant at 10 years old?

 

[Concerto]

We know it lasts the rated 10 years. Anything beyond that is irrelevant and pure luck. I’m sure impellers last more than a year but I change it anyway because that’s the service schedule.

Sorry I have to say that a major hole in the hull should not rely on an adhesive that has only a 10 year life. By comparison an engine hull seal is only a single opening that is bolted down and is under constant pressure, and only has to be lifted out to be replaced. All the hull windows will have to have the existing bonding broken and then fully cleaned on both surfaces before having the window rebonded under pressure - provided the window comes out cleanly and undamaged. If any of the windows are damaged, how easily will it be to obtain replacements, especially in some distant port. Which ever you look at this problem, it will cost a fortune after 10 years and could become the cost that devalues secondhand values substantially.

 

[seeSimon]

...

As to the CAT A+ there is a great deal of ignorance about the purpose of the RCD and how categories are established and the main differentiators between the categories is the expected weather conditions in the area of intended use. The more severe the greater the requirement for stability, recovery after knockdown, watertight integrity and type of equipment. As to standards of design and construction, these are covered by a range of recognised standards which the designer and builder needs to show have been used before the boat can be certified. It is never clear from the armchair critics what they would expect an additional category to look like. Suspect what they really want is boats such as were being built 40 years ago - skeg hung rudder, long keels (preferably encapsulated) high ballast ratios, mast head rigs, shaft drive engines, no windows in the hull, small bolted in coachroof windows and so on. There is nothing in the RCD that stops the design and building of a boat with these features - indeed there are more than one of that type still available. However that is not what buyers want - they have the choice but prefer the benefits that come from spade rudders, deep bolt on fin keels (or lifting keels and internal ballast), efficient all furling fractional rigs, saildrive engines, light and airy interiors and so on. Alternatively they can ignore all this and buy a multihull.

The purpose of the RCD was to establish a common minimum standard of design and construction in the EU and to provide information for consumers to help them choose a boat appropriate to their needs. The process is the same whether one is buying a boat to potter around on rivers or lakes or for a circumnavigation. At each level there is a huge variety of choice of products. The interesting thing with these threads is that the noisy critics of (usually) anything modern is that they are rarely buyers of new boats, nor even recent modern boats but own or lust after older boats. Their underlying (or even overt message) is that people should buy boats just like theirs or what they would buy. Who among new (or modern) boat buyers care what these critics say or do, particularly when the real evidence that is all around them shows that the majority of boats do not conform to outdated minority personal views.

I would be interested to hear why forumites think the RCD apparently allows my tender (9ft Tehri), small angling boat (14ft Orkney coastliner) and Yot (UK 2014 built Bay Cruiser 26) ALL to be "certified" as RCD Cat C.

Not worth the paper it's printed on, and most certainly not the cost of the plaque screwed to the transom!

...and worth about as much as the CE/"Wheel Mark" on commonly seen chinesium "lifejackets", flares and various other safety equipment.

Dangerously, fraudulently, misleading "standards" ?

PS. Nothing wrong with any of the above boats, but the RCD C thing is clearly utter b0LL0X!
See my comment at #54 re builders/sellers marking their own homework...

 

[lustyd]

Which manufacturers say replace the sealant at 10 years old?

Sika etc.

 

[geem]

Sika etc.

Nothing from the boat manufacturers?

 

[lustyd]

Nothing from the boat manufacturers?

I’ve no idea, I don’t have such a boat. As I said at the top of the thread though, your boat manufacturer says nothing about maintenance of other major parts, it’s expected that you understand maintenance needs to be done either by the owner or a professional.

 

[westernman]

Sorry I have to say that a major hole in the hull should not rely on an adhesive that has only a 10 year life. By comparison an engine hull seal is only a single opening that is bolted down and is under constant pressure, and only has to be lifted out to be replaced. All the hull windows will have to have the existing bonding broken and then fully cleaned on both surfaces before having the window rebonded under pressure - provided the window comes out cleanly and undamaged. If any of the windows are damaged, how easily will it be to obtain replacements, especially in some distant port. Which ever you look at this problem, it will cost a fortune after 10 years and could become the cost that devalues secondhand values substantially.

The B787 relies on an adhesive to hold the hull together and also the windows.

If it is good enough them, why should it not be good enough for a boat which does not go through anything like the pressurization/depressurization cycles that a B787 does. There is over 1000 litres of glue holding the B787 together.

 

[Ammonite]

We know it lasts the rated 10 years. Anything beyond that is irrelevant and pure luck. I’m sure impellers last more than a year but I change it anyway because that’s the service schedule.

No we don't. See post #40. That was in 2022.

 

[lustyd]

No we don't. See post #40. That was in 2022.

And the age of the boat was unknown, as I assume was its history. For all we know that window might have been forced out and reglued with pritt stick.

 

[Concerto]

The B787 relies on an adhesive to hold the hull together and also the windows.

If it is good enough them, why should it not be good enough for a boat which does not go through anything like the pressurization/depressurization cycles that a B787 does. There is over 1000 litres of glue holding the B787 together.

The big difference between yachts and civil aircraft is aircraft have very rigid maintenance schedules and the structure is visually inspected between every flight. I certainly cannot see. A full visual inspection by the owner/skipper of every hull window before every sail would be expected. However, how does that happen in mid ocean and if a problem is found, where do you get the problem solved?

 

[Ammonite]

And the age of the boat was unknown, as I assume was its history. For all we know that window might have been forced out and reglued with pritt stick.

It was a Farr designed Bavaria 37 which was introduced in 2013, but stick to your pritt stick theory if you like

 

[westernman]

The big difference between yachts and civil aircraft is aircraft have very rigid maintenance schedules and the structure is visually inspected between every flight. I certainly cannot see. A full visual inspection by the owner/skipper of every hull window before every sail would be expected. However, how does that happen in mid ocean and if a problem is found, where do you get the problem solved?

The inspection before a flight is very rudimentary. It is just the pilot or copilot walking around and seeing if there is a flap hanging open which should be closed, is there anything leaking out where it should not be, is one of the tires flat?

When a problem is found mid ocean in a B787, how do they fix the problem?

It is true. Airliners have strict inspection and maintenance schedules. Perhaps that should be the case for trans-oceanic yachts?

A MOT for boats anyone????

 

[Pye_End]

At best bonded hull windows introduced another maintenance item, and at worst a potential weakness/failure point - possibly catastrophic. Is the trade-off really worth it?

With regards to maintenance, it's all very well saying it must be done at 10 years, but realistically how many owners would either know this had to be done, or even get on and do it?

 

[westernman]

At best bonded hull windows introduced another maintenance item, and at worst a potential weakness/failure point - possibly catastrophic. Is the trade-off really worth it?

With regards to maintenance, it's all very well saying it must be done at 10 years, but realistically how many owners would either know this had to be done, or even get on and do it?

May be the insurers would ask for these to be rebonded every 10 years. Just like they want the rigging changed every 10 years whether it is necessary or not?

 

[AngusMcDoon]

At best bonded hull windows introduced another maintenance item, and at worst a potential weakness/failure point - possibly catastrophic. Is the trade-off really worth it?

With regards to maintenance, it's all very well saying it must be done at 10 years, but realistically how many owners would either know this had to be done, or even get on and do it?

One of my main cabin windows started dripping after 14 years. It's held in with Moonlight frames on each side pulled together with one hundred and umpteen screws with butyl rubber sealant between the frames, the hull and the window. Being butyl rubber it never sets hard so once all the screws had been removed a bit of levering and the frames came off easily. Even old butyl rubber is dissolved by white spirit so cleaning the frames, hull and window was an easy, if gooey, job to do. After cleaning everything was degreased with acetone. Replacement butyl rubber strip is available on ebay for about a fiver and is simple to unroll into the frames before reassembly. Then came the one hundred and umpteen screws to replace and tighten around the frame a few times. Final job was cut off the squeezed out sealant with a penknife. The whole job took a single warm summer's evening and the window hasn't leaked again.

Meanwhile, a friend has a similar aged Beneteau with bonded in windows. The bonding is failing and there are drips. A boatyard refused to quote because they say that there is a high chance that the window will break when removing it. Beneteau no longer supplies a replacement. A bespoke glass forming company has quoted thousands for a replacement. He's unsuccessfully bodged some sealant around the outside which looks a mess and lives with the drip.

Whether bonded windows are safe compared to bolted windows or not I don't know so I'm not going to comment on that. However, I know which construction technique I prefer to have on my boat and live with as both the boat and I get older.

It was that long narrow eye-shaped one...



In my biased and ignorant opinion on-going maintenance of windows, some of which will inevitably leak as boats get older, is a much more important issue than the safety or not of bonded in windows. From a sample size of one of either type bolted in are easy and cheap to maintain and fix by the average boat owning bodger whereas bonded in are difficult to the point of even a boatyard refusing, and have the risk of being very expensive. The idea that the owner of boats with bonded in windows will rip them out every ten years to replace the bonding because that's what Sika say is the lifetime of their goop is, frankly, ridiculous. We all know that will never happen.

 

[potentillaCO32]

The B787 relies on an adhesive to hold the hull together and also the windows.

If it is good enough them, why should it not be good enough for a boat which does not go through anything like the pressurization/depressurization cycles that a B787 does. There is over

This is a frankly nonsense comparison. Aircraft have every component identified and approved and only approved suppliers for each part. There is an inspection and.replacement schedule - and method - for every component.
A boat has nothing like that. Plus there is no requirement to continue to supply spare parts for any length of time.

 

[geem]

The B787 relies on an adhesive to hold the hull together and also the windows.

If it is good enough them, why should it not be good enough for a boat which does not go through anything like the pressurization/depressurization cycles that a B787 does. There is over 1000 litres of glue holding the B787 together.

I asked Halberg Rassy what they glued their hull windows in with on their new 370. They told me they use a PU adhesive. Nothing fancy. Not a structural silicon or a Modified Polymer Silica. PU has the worst UV resistance. No mechanical fixing either.

 

[AngusMcDoon]

I asked Halberg Rassy what they glued their hull windows in with on their new 370. They told me they use a PU adhesive. Nothing fancy. Not a structural silicon or a Modified Polymer Silica. PU has the worst UV resistance. No mechanical fixing either.

And the reason why nearly all builders now use this method...

1) The marketing wonks want it because it makes the boat look sleeker

2) It's low cost and easy for the builder. A tube of sealant is a tenner and no difficulty getting the installation right in a warm dry factory. A custom designed pair of Moonlight frames like in my photo above costs €100's a set when only a few to a few dozen are ordered a year by the builder.

Cheap, quick. Feck the 3rd owner 15 years down the line when it leaks and there are no spare parts trying to get a window out without breaking it and rebonding it in Welsh drizzle. What's not to like?