Rudder Failures

[avb3]

Originally Posted by smackdaddy

What does "properly glassed in" mean? And when Plexus makes this claim about it's FG adhesive...



How is that inferior to the "proper glassing" of yesterday?

I think you need to provide some proof of what you're claiming...or at least acknowledge that these Plexus guys might know something you don't.

Smack, I think the issue that was pointed out many pages ago is that some boat manufacturers are using Plexus to bond plywood to fiberglass, whereby eliminating the advantage you point out. In the past, the plywood was used as a substrate for fiberglass, and as such, if in that case Plexus would be used, perhaps the issue of plywood delamination would go away.

Perhaps the question that needs to be asked is why is there a direct plywood to fiberglass 'green snot' process done.

Adhesives CAN be beneficial; afterall, they use them in building aircraft. But it needs to be used correctly. Just using them does not make it good.

[a64pilot]

I give up if I wasn't on the Ipad with the app, I'd post several white flags

[Dockhead]

Originally Posted by minaret

Rebuilding a Pacific Seacraft rudder now. How many rudders have I had to fix which broke first? Several. How many have I repaired, rebuilt, or replaced, which were headed for imminent failure? Many. Dozens, for sure.

Want to decrease the odds of rudder failure, or, much more likely, a rudder rebuild? Don't buy a cheap boat with under built steering gear.

I think all this talk of percentage of boats who suffer failure at sea means little. Most bad rudders are caught before failure. Percentage of boats which have had a rudder replaced or rebuilt might be more revealing.

Slight thread drift, Minaret, but I will have my boat out of the water this winter for another minor refit, and am planning to drop the rudder out and do complete inspection of the entire steering system. Can you give advice on what to look for? I'm sure will be great help to many on this thread.

[robert sailor]

Smack, if Plexus is everything you and they claim it to be why did the rear bulkhead in Blue Pearl collapse? Why did the top of the rudder tube held with Plexus come apart? Why have many bulkheads come loose over the years using this method?
If you can name me a high quality boat that uses Plexus to hold plywood bulkheads in place I'd like to hear it because to my knowledge its only the cheap seats that use this? Its not yesterdays way of boat building, its simply the best way but you need skilled workers and it costs. The kid on minimum wage with a chalking gun and a precut bulkhead will fit the bill to install a bulkhead in some production boats but he would not find work with a quality builder.
Look I won't debate whether Plexus is a super glue because it is and for certain purposes its pretty hard to beat it but when you glass bulkheads in place properly it makes an almost bullet proof detail and this detail is used by every high quality builder out there to my knowledge. The downside? Its not cheap but that's life.

[smackdaddy]

Originally Posted by avb3

Smack, I think the issue that was pointed out many pages ago is that some boat manufacturers are using Plexus to bond plywood to fiberglass, whereby eliminating the advantage you point out. In the past, the plywood was used as a substrate for fiberglass, and as such, if in that case Plexus would be used, perhaps the issue of plywood delamination would go away.

Perhaps the question that needs to be asked is why is there a direct plywood to fiberglass 'green snot' process done.

Adhesives CAN be beneficial; afterall, they use them in building aircraft. But it needs to be used correctly. Just using them does not make it good.

That makes sense. And I agree that the plywood issue is suspect - but would epoxy over that same plywood be better? In other words, is it the adhesive or the plywood that's the real problem in this case?

[transmitterdan]

Originally Posted by smackdaddy

How is that inferior to the "proper glassing" of yesterday?

I think you need to provide some proof of what you're claiming...or at least acknowledge that these Plexus guys might know something you don't.

In the pictures posted earlier they are not using Plexus to join two fiberglass surfaces. One of the surfaces is plywood. What does the manufacturer of Plexus think about that? I know what I think.

[robert sailor]

Plywood makes excellent bulkheads, the only thing better is some of the new composite bulkheads that are lighter and stronger. Tabbing on a bulkhead is several layers thick and its common to have the tabbing overlapping the plywood several inches which gives it a real large bonding surface. Many builders even go a further step and through bolt the bulkheads through the tabbing to have both a mechanical bond as well as a chemical one. If the job is done properly it really is strong and enduring.

[smackdaddy]

Originally Posted by transmitterdan

In the pictures posted earlier they are not using Plexus to join two fiberglass surfaces. One of the surfaces is plywood. What does the manufacturer of Plexus think about that? I know what I think.

Yes, like I said above, I agree that that's much more suspect than the adhesive itself (I actually pointed it out in post 166 soon after those photos were posted).

But, again, does this mean that epoxy/glass-tabbing would be better with this same plywood substrate? Or does it mean that the plywood itself is the real problem here? If the latter, then the manual tabbing doesn't really buy you anything - and we're back to the potential superiority of Plexus over tabbing.

Again - I'm only bringing this up to point out the flaw in thinking that these new technologies are somehow inherently inferior.

[robert sailor]

The downside of having bulkheads glassed to the hull is that you can not use the full piece liners that are now in vogue. You have to build the interior furniture and glass it into the hull as well. Time and money. These liners were designed to reduce costs by cutting back on labor and material. Some builders glue the bulkheads into recesses in the liners designed to accept the bulkhead but then the bulkhead depends on the liner staying intact which it does most of the time. If the liner ever has a failure then you may as well not have bulkheads because they won't be doing anything. I like the new production boats, well many of them anyways, there is lots to be attracted to but high build quality is not one of them.

[Polux]

Originally Posted by neilpride

Im not talking about perfomance, im talking about construction metods and strenght..

Performance is an essential part of a sailboat; they are built to sail and a better performance makes a better sailboat. performance is not only speed but the way the boat goes upwind, less roll downwind, sailing with less heel and so on.

Today sail boats, like cars have a much better performance regarding 40 year old boats (or cars). That is only possible because the design is better, the materials stronger and the construction methods more advanced.

[DeepFrz]

Why do you think it is different with boats?

For one thing, there isn't the oversight for boat manufacturers (pleasure boats) that we have in the auto industry. No crash test dummies, so to speak. No one ensuring that there is a bilge sump that will hold a couple of gals. of water. Throw 5 gals. of water into many of the modern production boats in a seaway and you have big trouble. The water washes up the sides of the hull and pretty soon you have no electronics. There aren't even any regulations on what capacity bilge pump has to be installed. No one watching what the layup schedule is or if the layup is getting thin that there is a sandwich core to make up the strength. No one that says with authority that all areas of the hull need to be accessible in case of a collision that holes the hull. In fact there seems to be no legal ramifications if a builder turns out a dangerous boat.

Those are just some of the differences between a modern auto manufacturer and a modern boat manufacturer.

[DeepFrz]

Wow, I go out for the afternoon and 2 pages of posts...I post a reply and then realize the question has probably been long forgotten...LOL

[neilpride]

Originally Posted by smackdaddy

Well, then you've got a problem on your hands. Right now, you keep listing a single (non-hurricane-damaged) Bene as your example to condemn the entire line. There are, maybe, thousands of them out there built pretty much exactly the same way. And they are doing fine.

So, if they are, indeed, as weak and poorly built as you insist they are, there should be many, many more falling apart than there actually are.

So someone is wrong. And I tend to go with numbers over opinion.

And though I definitely respect your knowledge and experience in repairing boats - I don't buy your conclusions. For example...



Isn't there a standard manual bilge pump as backup? And if the bilge sump is that small, do you really need a 1500 or 2000 pump as a standard?

For example, if you do the rough math on that bilge sump with your measurements - and assume that it's maybe 6" deep ("shallow" like you say) - my calculator comes up with 162 cubic inches of volume (3X6X9). A single gallon of water is 231 cubic inches. And the existing Rule 1100 pump can move 1100 of these in an hour. So, exactly what are you designing for on this boat when choosing the 2000?

And have you ever wondered why there isn't constant complaining about the floorboards always being awash in these newer production boats because the bilges are "too small"? Maybe, just maybe, the common problem that you're imagining requiring double the amount of water movement isn't there?



Though I agree it might not be the "best" way to install wiring - I can guarantee you that I (and most others) don't want to pay extra in design and construction costs to make your job repairing and adding stuff easier. Sure, it would be nice to have (especially for you) - but it's very, very low on most boat buyers' priority list. So if it meets common standards, doesn't sacrifice the integrity of the yacht, and the price/value are good - I don't really care if it presents difficulties when customizing the boat's systems, etc.

BTW - I'm still not clear...how did this Bene in your photos get damage? Did this happen while it was under sail offshore?

No Smack,, is not the single Beneteau pointed in this fórum, i have 4 waiting after the Beneteau, and i think you fail in the same wrong idea that all the incidents are posted in Sailnet or Cf sailing anarchy, quite wrong , i can point you right now 2 boats with serious problems and both owners even dont know about sailing fórums not even cruisers fórums.

Most problems are hooked in boatyards before something serious happen offshore, believe it or not, found the well reported incidents in this year regarding 2 beneteaus, a First and a Oceanis pls, one with a ripped keel and the other one with a plexus ripped rudder bulkhead.

A small rule bilge pump like the 1100 GPH is apropiate for a 35 to 40 ft boat , longer than that my personal experience call for a 1500 2000 gph pump, dont tell me Enginers make the right calculations because the right calculations fail under the deck cleat . There is a chart selection guide about bilge pumps v boat size,, Hell my boat is 44 LOA and the
old 1500 quite small for me so i swicht to a 2000 gph rule, quite a good diference..


About the small sump is quite normal in this boats since the keel and the hull are flat and only a small keel stub doing the job as a bilge sump, i dont mention the boat sport a full liner with lots of compartments and a small limber hole for each compartment conecting with each other, seriously a 1100 gph is wrong wrong!!! It have a manual bilge pump, but can you stay day and night at the dock just in case??

And to finish, about the wiring sure you dont know what you talking about mention the wires crushed between deck and liner, is not for me, is for the owner, DY if you know what i mean , and to pass new wires you are doomed to make holes in the liner and found a way to bring the wire to the cockpit without mention the risk of fires onboard due shorts in wires...

Frankly i dont post the pics to show a hurricane damage boat, any boat in a hurricane can get damage , i post it to show how bad is made the rudder top post structure in relation to this topic Rudder failures. Thats all, im not a production boat hater, im a badstuff hater no matter if is a production boat or a custom design...

If you want to know more about FG tabing around bulkheads you can PM Minaret in this fórum and reach a dam conclusión for god shake mate..
Cheers..

[Dockhead]

Originally Posted by DeepFrz

Yes, some do jump to extreme conclusions, don't we Smack...

Of course I'm not implying that. I was referring back to a previous post where it was inferred that boats are designed to such high standards because of the experience of NAs and the excellence of engineering software. And then in the first 36 hrs. of a race there are a significant number of failures, one requiring rescue and others requiring towing. I have great respect for many NAs and I also have respect for engineering software. But they aren't infallible and they often push designs to such an extreme that failure is almost inevitable. The same thing for racing and/or cruising designs.

There are people on this forum who make there living repairing boats. They know good boats and they know bad boats. Some have spoken out and said what they think of some of the modern production boats. It ain't pretty. I don't know what interest you have in these boats but I have no dog in this race. But I can read, listen and make decisions based on what people who know and whom I respect say. I have been sailing and interested in sail boats for a lot of years and I have seen a lot of ***** masquerading as yachts...some from good NAs but bad builders, some the other way around.

I don't think much real engineering goes into any sailboat, whether they be "production boats", or high end so-called hand made ones.

Just because you own a FE analysis software package which allows you run a few calculations doesn't mean that you've done a proper engineering job. To really engineer something as complex as a cruising sailboat -- that is, to really engineer it the way cars are engineered -- would cost many millions of dollars and will require some destructive testing -- and it just ain't happening, whether we're talking about Swans, or we're talking about Bavarias.

Theoretically, "production boats" should be much better engineered than other boats -- because with volume they have some chance of amortizing the costs. But I don't actually think the production methods are so different between them -- the massiest mass production sailboat is still quaint arts & crafts -- practically basket weaving -- compared to the way cars are made.

I think most of the "engineering" which goes on is basically, how much are we willing to overbuild this. And the maker of an expensive, prestigious, low production boat will simply supersize everything to create big margins of error -- because the prestige of his marque enables him to charge enough to cover the costs. Something which Bav and Bennie can't do.

That doesn't mean that Bav and Bennie are necessarily carp. Groupe Beneteau's products, in particular, are clearly the result of a fair amount of intelligent thought, even if most of this does not rise to the level of actual engineering. But there will be less of the overbuilding which passes for "engineering" in our field, so more maintenance and more inspection is an excellent idea.

A case in point might be Oyster, who until recently insisted on full skeg rudders despite the huge performance hit from that antiquated design. That's a substitute for actual engineering, which, I submit, is not much done with sailboats, at least those which are not being made for America's Cup.

[Polux]

Originally Posted by robert sailor

Polux I don't doubt for a moment that a Bavaria 44 got around the world or that a 36 did it twice after all Catalina 27's do it too as well as old Cal 25's so doing it may not be the best reason to choose either of these boats as an all around offshore boat.

That is not the point. I am not saying that there is not better bluewater boats or even that those boats are specially adapted to it. The point is that if they where so weak has some here make us believe they would never be able to do it, falling apart on the process: they would lose the rudder, they would lose the keel, they would have structural problems.

We are talking in making a number of miles that is more than the double or than what most sailboats do in their entire life. Nobody does a circumnavigation or sail extensiveness without getting some bad weather on the way even if one tries to avoid it and you should know that (you now that!)

Originally Posted by robert sailor

The Beneteau 50 is probably more boat than either of the Bavarias and it came to grief and sunk when the plywood bulkheads held in place with glue failed to do the job when the skipper and crew ran into some rougher weather in the north Atlantic. Watching that video was enough for me as I watched the boat come apart in conditions that it should have been able to deal with, it just wasn't that bad, I've certainly been in a lot worse.
..

And there you go talking about one Beneteau that have problems when there are 15000 of them sailing around, many crossing oceans and circumnavigating!!!!

Don't you think that if the Beneteaus have serious structural problems, like the ones that Oceanis 50 showed, we should have on those many thousands of Beneteaus a fair number of boats with big structural problems? I am not talking about much, let's say 1%, the ones that eventually are used in an harder way. That would make for 150 boats NOT ONE BOAT!!!!

Don't you think, that due to the lack of a significant number of accidents with other Oceanis, it is more probable that boat had an hidden manufacturing defect, a non detected one that caused a catastrophic failure? or, that a previous non reported accident or grounding had weakened the boat structure? As you know that boat was bought used and if I am not wrong had a previous accident before the one that lead to its loss.

One boat in 15000 and you don't stop to talk about it