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Old 15-11-2014, 09:57   #916
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Re: Rudder Failures

Smack,
Blue Pearl was completely surveyed after the rudder was replaced so maybe it just failed or maybe the surveyor missed something but you and I do not know for sure, that is a fact, its actually the only fact. I have not see evidence of any substandard repairs, maybe you can pass on your evidence to the group here, evidence please, not hearsay.
As to you seeing enough good credible evidence whether one method is better than another, quite simply, it would take someone with a high level of understanding in boat structures to decide that question, do you feel you are the best person to make that call. And if the call is just a personal thing, is there a benefit to others?
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Old 15-11-2014, 10:08   #917
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Re: Rudder Failures

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Originally Posted by Polux View Post
I don't understand what you mean. The tie rod is linked to a massive plywood bulkhead. Bavaria use that system for many years and I had a Bavaria that had the chainplate linked like that.

We can see on the bigger picture that is not Plexus or any other glue. What I saw is broken fiberglass on the base of the bulkhead that was laminated to the hull. It still retains the hull shape.
I see what you mean. So this is a good example of catastrophic failure of tabbing? Interesting.

And if a boat like this is aggressively raced in regattas like the Heineken - I think we are talking a completely different kettle of hamsters than cruising.
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Old 15-11-2014, 10:09   #918
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Re: Rudder Failures

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Originally Posted by smackdaddy View Post
This is actually one of my primary points. I'm writing up a blog post on it now. When you look at the list of the items that have always been the differentiators in the "bluewater debate" - you see that most of those things are going away in even the traditional bluewater brands. You have to ask yourself - why?

For example, here's a brief list of the "proper bluewater" considerations off the top of my head:

1. Displacement/weight of the boat (and comfort ratio, etc.)
2. Hull shape
3. Size of cockpit
4. Size/orientation of companionway hatch
5. Handholds
6. Seaberths
7. Capsize ratio
8. Layout of galley
9. Keel/rudder configuration
10. Rig configuration

And probably lots more I haven't listed.

So, when you look at the new boats from these brands, how many of them are lining up with how you've always defined the above? And how many of them are looking more like the production boats you swore you'd never sail?

On this...



Bingo.
I think you make a point but for the most part boats like Oysters do by and large check the boxes except on some models from the pic's you guys are posting they are shy on proper hand holds but they are wonderfully built and meet a much higher bench mark than today's lower priced production boats. You can say the same about other high quality boats even though many are not purchased with the idea of using them for cruising. Another way to look at is, do their rudders fall off quite often, do they lose their keels, do the anchors holding their shrouds rip up through the deck, do the bulkheads break away from the structure, do they oil can while sailing to windward, are the bilges so shallow that a cup of water in them will end up in the furnture etc. etc. Put that check list for the cheaper production boats and see how they fare.
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Old 15-11-2014, 10:14   #919
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Re: Rudder Failures

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Smack,
Blue Pearl was completely surveyed after the rudder was replaced so maybe it just failed or maybe the surveyor missed something but you and I do not know for sure, that is a fact, its actually the only fact. I have not see evidence of any substandard repairs, maybe you can pass on your evidence to the group here, evidence please, not hearsay.
Sure - read that thread. It's all there. You might think it's good practice to replace a rudder while the boat is in the water because you don't want to (or can't) spend the money to haul it. I don't.

There are several other things in that same thread that point to the same outcome.

As I say, that boat is off my list of credible examples. Keep it on yours if you want.
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Old 15-11-2014, 10:15   #920
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Re: Rudder Failures

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Originally Posted by smackdaddy View Post
I'm not trolling. I'm just very interested - but I'm also skeptical. I don't usually just accept stuff people say in forums. If interested, I put some time into researching it.

To me, this is actually a very important issue because it deals with how newer boats are being put together. If there are serious, recurring issues with the use of Plexus (which is apparently being used a lot), I'm very interested in knowing that. I think many people are very interested in knowing that.

Blue Pearl is NOT a good example. When you say "If the stuff is so great Blue Pearl never should have loose the structure? right?" Wrong. With what that boat went through with the damage and sub-standard repairs, it means very little to this debate.

So, the bottom line is that any reader has two things to consider:

1. A vast majority of the industry appears to be using adhesives like Plexus more and more to replace tabbing. As the reports I've posted show, there is scientific evidence that this is a viable alternative.

2. Some repair guys are providing some examples of bond failure - and strongly implying that the industry and science is wrong. That the traditional building means are categorically better.

Which of these is a discerning reader going to put his faith in? I think the answer to that is the amount of good, reliable evidence behind each. If I see enough credible evidence that these Plexus bonds are failing in significant numbers, I'm perfectly willing to accept that it's not a good direction to go - and people should be concerned if their boat has been built this way (mine has from what I understand). But until then, I'm just not buying argument 2 above.

As for this part...



What is this about "moving the whole thing to my side"? Is that what we are trying to do here? Interesting.

As for Minaret's suggested test - it has nothing to do at all with what we are discussing. That test seems to measure flexibility. The report clearly says that Plexus is realtively stiff. So what? We are talking about bonding strength here. And when you tab a stiff bulkhead (instead of wax paper) do you really want it to be able to bend in a circle - or do you want it to maintain the joint and bond - exactly as was shown in the report's test?



Yes, brittleness/flexibility do matter. Plexus when properly used as designed, that is glass to glass, can be stiff/brittle with no problems because it is bonded to a dimensionally stable substrate which is also fairly stiff. But if you bond it to a dimensionally unstable substrate like wood, it's longevity suffers dramatically. Sure it produces an excellent initial bond, but over time as the wood expands and contracts and the adhesive does not, not to mention any flex, the bond will fail. It's not really very informative to make two new joints and lab test them side by side. How about after two years? Or after ten? The glass joint is more flexible and spreads load over a much, much wider area. All of the structural fillets I see are not even very big, and were not even made with a fillet ball. Just a plastic spreader and a minimum wage laborer.
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Old 15-11-2014, 10:16   #921
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Re: Rudder Failures

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Originally Posted by smackdaddy View Post
I see what you mean. So this is a good example of catastrophic failure of tabbing? Interesting.

And if a boat like this is aggressively raced in regattas like the Heineken - I think we are talking a completely different kettle of fish than cruising.
Hard to say, I agree it does look like tabbing but I don't know enough about the shape of structures that they glue on. Floor grids have similar profiles and they are glued so best to wait to see what the boat builders have to say.
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Old 15-11-2014, 10:21   #922
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Re: Rudder Failures

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Originally Posted by smackdaddy View Post
Sure - read that thread. It's all there. You might think it's good practice to replace a rudder while the boat is in the water because you don't want to (or can't) spend the money to haul it. I don't.

There are several other things in that same thread that point to the same outcome.

As I say, that boat is off my list of credible examples. Keep it on yours if you want.
You may want to look up the meaning of evidence. You have providing nothing.....still waiting!
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Old 15-11-2014, 10:25   #923
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Re: Rudder Failures

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Originally Posted by minaret View Post
Yes, brittleness/flexibility do matter. Plexus when properly used as designed, that is glass to glass, can be stiff/brittle with no problems because it is bonded to a dimensionally stable substrate which is also fairly stiff. But if you bond it to a dimensionally unstable substrate like wood, it's longevity suffers dramatically. Sure it produces an excellent initial bond, but over time as the wood expands and contracts and the adhesive does not, not to mention any flex, the bond will fail.
Okay - I definitely question your general stability analysis of glass and wood, but it's your last sentence that is actually the crux of this debate and goes back to the sacrilegious concept I brought up earlier in this thread:

What is the "useful life span" of a sailboat? What should it be?

As I said before, most of us own boats that are decades old. What do we expect their useful life span to be? When I buy a 45-year-old "bluewater" Cabo Rico, am I buying a boat that is much "stronger" than a 10-year-old production boat?

More importantly, should we expect a shorter life span on these newer boats? When I buy that 10-year-old production boat, should I be especially vigilant for things like the Plexus bonds to start failing? Or should I be ready for the keel to separate at some pont?

Should I expect to "dispose" of my new boat in 15-20 years?

These are critical questions for boat buyers out there. Because it sounds like expectations are seriously out-of-whack across the board.
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Old 15-11-2014, 10:27   #924
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Re: Rudder Failures

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You may want to look up the meaning of evidence. You have providing nothing.....still waiting!
Dude, I don't carry water. The thread is here. Go read it.
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Old 15-11-2014, 10:29   #925
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Re: Rudder Failures

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Originally Posted by smackdaddy View Post
I see what you mean. So this is a good example of catastrophic failure of tabbing? Interesting.

And if a boat like this is aggressively raced in regattas like the Heineken - I think we are talking a completely different kettle of hamsters than cruising.
Actually on review I think what we are seeing here is the result of all the new high tech engineering, materials and designs using the latest and greatest computer models that tell us exactly how to build a much superior boat than was done in the past. To suggest that the boat was racing and not cruising is a bit of a joke as years ago when we had a large local fleet we raced twice a week in all kinds of conditions and nobody ever even dreamed about massive structural failure. Imagine if that happened offshore.
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Old 15-11-2014, 10:31   #926
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Re: Rudder Failures

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Originally Posted by robert sailor View Post
Actually on review I think what we are seeing here is the result of all the new high tech engineering, materials and designs using the latest and greatest computer models that tell us exactly how to build a much superior boat than was done in the past. To suggest that the boat was racing and not cruising is a bit of a joke as years ago when we had a large local fleet we raced twice a week in all kinds of conditions and nobody ever even dreamed about massive structural failure. Imagine if that happened offshore.



Exactly! Grid liners are bad enough by themselves, but tying a chainplate into one by tie rod?! Especially a very small partial with a teeny footprint. Very little faying surface.
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Old 15-11-2014, 10:32   #927
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Re: Rudder Failures

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Dude, I don't carry water. The thread is here. Go read it.

No I know you don't but you expect others to. If you make a statement concerning evidence that you have then why not put up?
If you don't have any evidence and its simply second hand hearsay then buck up and admit it.
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Old 15-11-2014, 10:37   #928
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Re: Rudder Failures

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No I know you don't but you expect others to. If you make a statement concerning evidence that you have then why not put up?
If you don't have any evidence and its simply second hand hearsay then buck up and admit it.
If you're that disinclined to actually use the search feature, you can at least look back in this thread to where CPA and I discussed the two Blue Pearl threads in question.

I think I've brought plenty of evidence into this and the other thread to back up my questions/arguments.

So, yes, I expect others to do the same. I'm certainly not going to do it for them...not even you.
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Old 15-11-2014, 10:43   #929
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Re: Rudder Failures

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Originally Posted by smackdaddy View Post
Okay - I definitely question your general stability analysis of glass and wood, but it's your last sentence that is actually the crux of this debate and goes back to the sacrilegious concept I brought up earlier in this thread:

What is the "useful life span" of a sailboat? What should it be?

As I said before, most of us own boats that are decades old. What do we expect their useful life span to be? When I buy a 45-year-old "bluewater" Cabo Rico, am I buying a boat that is much "stronger" than a 10-year-old production boat?

More importantly, should we expect a shorter life span on these newer boats? When I buy that 10-year-old production boat, should I be especially vigilant for things like the Plexus bonds to start failing? Or should I be ready for the keel to separate at some pont?

Should I expect to "dispose" of my new boat in 15-20 years?

These are critical questions for boat buyers out there. Because it sounds like expectations are seriously out-of-whack across the board.
Smack,
Dave from Goboatingnow seems to be a fairly knowledgeable guy and he tells me that the new production boat structures are rated for "X' number of cycles, he has the numbers. Apparently this is part and partial to the CE rating. When the B 40 lost her keel he surmised that quite simply she may have been sailed to hard for too long and was basically worn out.

I was speaking to a very experienced British surveyor when we bought our recent boat and he said that for the first time in his career he was surveying boats with "limited" lifespans.

So there may be something to what these two gentlemen have to say, certainly both having a much larger base of knowledge than myself I just listened.
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Old 15-11-2014, 10:45   #930
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Re: Rudder Failures

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Smack,
Dave from Goboatingnow seems to be a fairly knowledgeable guy and he tells me that the new production boat structures are rated for "X' number of cycles, he has the numbers. Apparently this is part and partial to the CE rating. When the B 40 lost her keel he surmised that quite simply she may have been sailed to hard for too long and was basically worn out.

I was speaking to a very experienced British surveyor when we bought our recent boat and he said that for the first time in his career he was surveying boats with "limited" lifespans.

So there may be something to what these two gentlemen have to say, certainly both having a much larger base of knowledge than myself I just listened.
That is great information. And, honestly, I think that is precisely what we're seeing.

Thanks.
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