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Dawg

Rudder Maintenance

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This weekend we had a boat snap it's rudder and I took this shot.

The wood at the leading edge looks to be rotted, the foam looks to be old and fatigued. And it looks pretty damn thin for a 30' boats rudder.

I was not able to get in up close as these photos were as it was hauled.

 

The rudder snapped right as they were entering the breakwater. Not the best place to lose steerage. I crew hurt pretty bad and I have not heard on his status.

 

gallery_3_148_1082899.jpg

 

 

 

This guy is rolling a cigarette, not a joint. I guess that is the only way you can afford to smoke in Calif now. :)

I was looking at the boat not him when I snapped the shot.

 

gallery_3_148_1550774.jpg

 

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When that rudder snapped, it must have been really pissed off to cause all that damage.

 

They were under kite and rounded up, had to get sails down and waves tossed them into the Breakwater.

The breakwater is pretty hard.

It was like the worst place at the worst time. Murphy's law.

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Not murphays law as much as cowboys doing dumb stuff and lack of quality buid/ maintenance.

 

Rudders are most stressed and damaged at the area directly below the Lower pintal and waterline! This is where they need carefully engineering with heeps of tri axial and uni glass and a load map done to spread the load over this area int surrounding areas of the blade. This rudder looks like a " apprentice weekend off job"...

 

The wood was rotten due to piss poor inspection/ maintenance of this critical area. This isnevident by the condition of the rudders paint and the obvious rust staining etc on the rudder.

 

I would say objects have been hitting this critical area over the season/s and damaged the inadequate glass letting the water in.

 

Said dude should give up rolling joints and look more closely at his kit!

 

Also, sailing into a tight marina with a spinnaker, a poorly maintained rudder, a can in one hand and a fag in the other, might feel good for the sailors, but is just asking trouble!

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Not murphays law as much as cowboys doing dumb stuff and lack of quality buid/ maintenance.

 

Rudders are most stressed and damaged at the area directly below the Lower pintal and waterline! This is where they need carefully engineering with heeps of tri axial and uni glass and a load map done to spread the load over this area int surrounding areas of the blade. This rudder looks like a " apprentice weekend off job"...

 

The wood was rotten due to piss poor inspection/ maintenance of this critical area. This isnevident by the condition of the rudders paint and the obvious rust staining etc on the rudder.

 

I would say objects have been hitting this critical area over the season/s and damaged the inadequate glass letting the water in.

 

Said dude should give up rolling joints and look more closely at his kit!

 

Also, sailing into a tight marina with a spinnaker, a poorly maintained rudder, a can in one hand and a fag in the other, might feel good for the sailors, but is just asking trouble!

 

The guy in the photo does not own the boat and he was rolling a fag as you say it. You can see the blue bag he is holding.

I do agree though about the maintenance. Having worked in a boatyard and own my own boat, I know how people become complacent.

The romance of the sea is too alluring.

 

This boat came from the SF Bay area to SB after it was sailed hard. I was told the original name was "Sparky"

Between the owner in SB and 2 owners here, It has been raced hard, hung up wet and I believe it got a new mast a few years back.

All sorts of stories are flying around now from former crew about how bad the rudder was, way back.

The current owner has been negligent in my opinion and will probably be on the hook.

 

 

Status on the guy that got hurt, I think he is in his mid 20's:

He apparently had a line wrapped around his lower leg and almost had it pulled from his body. after cutting the line he was bleeding out apparently pulled so hard everything separated and the major artery ruptured. They tournicated his upper leg. It probably saved his life. The report is he will not lose his lower leg but I know it will ever be 100%. I'm not sure how extensive the damage is and whether he will need a knee replacement.

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Sparky? Name rings a bell. Mull 30 IIRC - basically a 30 foot version of the Pocket Rocket 22, which also had an OB rudder.

Mull 30

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After heads cleared the report is the guys leg was squeezed pretty bad, enough to cause bleeding but not as bad as first reported.

The leg will heal but the boat is probably going to be a loss. Depends on the Insurance company. There may be a Project boat available soon.

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Go Fund Me

 

I gotta talk to the young man. I think his step dad gave him the boat if he fixes it. It's hurt bad in the main stress areas but not totaled. You could fix it I'd pay an engineer to give me the layup schedule so It is done right and then add some ring frames to stiffen it. I think the boat was wood with a glass skin and foam/glass on the inside.

Liability insurance don't cut it if you get damaged and want to keep the boat.. DOH

I bet they will entertain offers....................

 

 

Thank goodness I have real insurance for my boat. It's not that expensive when you consider the cost of hauling and destroying a boat you can't fix.

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well, when nothing goes wrong afterwards, rudder breakage can be ''fun''..... ( non of them is the owner :D )

 

 

gallery_116338_1152_727811.jpg

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well, when nothing goes wrong afterwards, rudder breakage can be ''fun''..... ( non of them is the owner :D )

 

 

gallery_116338_1152_727811.jpg

 

Looks a bit short on the glassing schedule?

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more like rotten wood core :)

The core offers no strength to the structure other than keeping the two layers of glass separated?

 

The Glass's layup is 100% at fault and has been slowly failing for a while, thus the water ingress into the core, and eventually gave up!

 

Probably compressed on one side and sheared on the other.

 

No body builds a bridge with random cross bracing so why do people use chopped strand and not tri axial and mprudent use of uni directionals cloths?... In situations like this

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more like rotten wood core :)

The core offers no strength to the structure other than keeping the two layers of glass separated?

 

The Glass's layup is 100% at fault and has been slowly failing for a while, thus the water ingress into the core, and eventually gave up!

 

Probably compressed on one side and sheared on the other.

 

No body builds a bridge with random cross bracing so why do people use chopped strand and not tri axial and mprudent use of uni directionals cloths?... In situations like this

 

 

The core does not directly offer strength, but if the core is no longer bonded to the skins or has zero shear strength, then the skins can't do their job in bending.

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more like rotten wood core :)

 

The core offers no strength to the structure other than keeping the two layers of glass separated?

The Glass's layup is 100% at fault and has been slowly failing for a while, thus the water ingress into the core, and eventually gave up!

Probably compressed on one side and sheared on the other.

No body builds a bridge with random cross bracing so why do people use chopped strand and not tri axial and mprudent use of uni directionals cloths?... In situations like this

 

The core does not directly offer strength, but if the core is no longer bonded to the skins or has zero shear strength, then the skins can't do their job in bending.

Have to think about that.. In relation to hollow foils with no core

 

If the layup is designed with a core then maybe?

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more like rotten wood core :)

The core offers no strength to the structure other than keeping the two layers of glass separated?

The Glass's layup is 100% at fault and has been slowly failing for a while, thus the water ingress into the core, and eventually gave up!

Probably compressed on one side and sheared on the other.

No body builds a bridge with random cross bracing so why do people use chopped strand and not tri axial and mprudent use of uni directionals cloths?... In situations like this

The core does not directly offer strength, but if the core is no longer bonded to the skins or has zero shear strength, then the skins can't do their job in bending.

Have to think about that.. In relation to hollow foils with no core

 

If the layup is designed with a core then maybe?

 

 

Take an I-beam as an example. The web adds almost nothing to flexural resistance, but is necessary to keep the flanges from moving relative to one another

 

One might argue that stringers are often hollow, but again you have a web, two of them to be exact. In any form of cored construction, the core acts as a web.

 

Having thought about this a bit more, I suppose you could have a hollow rudder that would have a degree of stiffness, or perhaps even full stiffness if the skins can be constrained adequately. The sectional shape alone may be adequate since any curvature, and particularly the leading edge would act like a web to some degree.

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Thought about this some more and realized I was wrong, at least with regards to flexure in a rudder. I've been dealing more with the hull and deck on my rebuild and haven't given much thought to rudders until now.

 

With a rudder, a better analogy would be a mast or tube even. The web notion still applies (which in a mast would be the fore and aft faces in lateral bending), but a core is not necessary at all in flexure. In these cases, stiffness comes from shape, or more precisely Ixx and Iyy

 

Now to curb localized distortion a core or thick skins are a necessity

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If brown stuff is accumulating around the lower gudgeon bolts ( or anywhere in your boat) quit using the boat until after you have removed those fasteners And inspected the core.

 

A guy brought a Catalina 22 rudder to my shop last week because he had dropped it did chipped the trailing edge.

I told him the chip was meaningless in his life's grand scheme of things and showed him why he needed to either immediately fix his rudder or get a new one.

 

 

First I took off the lower gudgeon. Then I sat in a chair, put the middle of the rudder against my knee such that the holes from the gudgeon were sealed against my knee...

Then grabbed both ends and flexed the rudder so it squirted smelly landt colored water with each arm pull.

 

I told him I wouldn't leave the dock with that as my steering wheel.

He agreed and iverbthe next few days we tinkered a bit.

 

We blew the compost out from inside, spun various sized flexible wire brushes around inside, blew it dry for a couple days, did the brush thing again, then pumped in a slurry of resin, chopped up glass, and glass spheres.

We also ground off the gelcoat and added a few layers of mat and unidirectional on the outside a few inches above and below the lower gudgeon.

 

Just for grins I ground away some gelcoat and stupid filler underneath it and wrapped the leading edge between the gudgeons with some glass layers

Then I slathered on some 3m Blister filler so I could quickly shape it somewhat decently

We sanded that, blew on some gelcoat , gave that a quick sand and hit it with a buffer.

 

All that crap took almost an hour of my time so I charged him $125 including materials for his better than new rudder.

 

There really is no excuse for using pre composted material as a core material in a plastic rudder

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Thought about this some more and realized I was wrong, at least with regards to flexure in a rudder. I've been dealing more with the hull and deck on my rebuild and haven't given much thought to rudders until now.

 

With a rudder, a better analogy would be a mast or tube even. The web notion still applies (which in a mast would be the fore and aft faces in lateral bending), but a core is not necessary at all in flexure. In these cases, stiffness comes from shape, or more precisely Ixx and Iyy

 

Now to curb localized distortion a core or thick skins are a necessity

You have been watching too many political "debates" and interviews.

 

I think you just thought you wrote something about cores and structure

Maybe?

Anyway..... Core in solid condition changes the handling of load from simple flex to stretch and compression.

 

When the core has turned to mush or is delaminates from the outer skins the structure is compromised

 

.mush core allows the skins to simply flex. The structure is no longer outside walls carrying stretch and compression.

As the original outside walls of cored laminates are quite thin, mush cited laminates become absurdly flexible

 

When the skin delaminates from the core, the stretch side generally is as resistant to stretch as when it is adhering to the core.

The compression side core no longer has the core to keep it in column and it crushes.

 

Think about a team of paper

If you glue all the pages together that team won't bend a bit but as simple sheets it bends easily

 

When the core around the gudgeons delaminates or becomes mushy.... The rudder breaks

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Thought about this some more and realized I was wrong, at least with regards to flexure in a rudder. I've been dealing more with the hull and deck on my rebuild and haven't given much thought to rudders until now.

 

With a rudder, a better analogy would be a mast or tube even. The web notion still applies (which in a mast would be the fore and aft faces in lateral bending), but a core is not necessary at all in flexure. In these cases, stiffness comes from shape, or more precisely Ixx and Iyy

 

Now to curb localized distortion a core or thick skins are a necessity

You have been watching too many political "debates" and interviews.

 

 

I think you are right.

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Thought about this some more and realized I was wrong, at least with regards to flexure in a rudder. I've been dealing more with the hull and deck on my rebuild and haven't given much thought to rudders until now.

 

With a rudder, a better analogy would be a mast or tube even. The web notion still applies (which in a mast would be the fore and aft faces in lateral bending), but a core is not necessary at all in flexure. In these cases, stiffness comes from shape, or more precisely Ixx and Iyy

 

Now to curb localized distortion a core or thick skins are a necessity

You have been watching too many political "debates" and interviews.

 

I think you are right.

Nah!! I would rather be wrong than agree with the rest of the world

 

Notice here how just after the start I am left of everybody and blew the lead before rounding the second lap leeward mark

easter%202015%20port%203.jpg

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Hobot, that is called a rudder post or shaft. Very normal to use something like steel or carbon or aluminum for the shaft that goes into the blade and provides much if not all of the vertical stiffness.

 

Not so typical for transom mounted rudders.

 

There is a very good reason for this, and its the reason so many small boats use transom rudders instead of inboard (under the hull) rudders.

 

Its far simpler and cheaper, and more resource efficient (money, materials, and labor) to build a rudder consisting of a core and skins. This is because the further material is from the neutral axis, the more effective that material in both stiffness and strength. The increase is highly non-linear, so a small increase of distance from the neutral axis makes a large difference in stiffness and strength. Using a rudder shaft internal to the foil means the rudder shaft material is closer to the neutral axis, and therefore less effective than if the skins were taking all the load.

 

On a rudder, this difference is large, because the load is not strictly sideways (where you lose the thickness of the skins and the filler and bonding material between skin and shaft). Its also at a slight angle and a bit aft of the rudder post, where you lose by a much greater amount. Remember: reducing the distance between structural material (skins) and the neutral axis by even a small amount on a rudder means you lose by a large amount in strength and stiffness, which means weight and money.

 

If you took the Westlawn course, you would know this, and lots of other stuff that is critical to making boats (and other things) actually work.

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Carcrash, I appreciated your answer up until the insult with the last paragraph.

 

Why would I go and take the Westlawn course? Theres nothing they teach that would benefit me now or put any money in my pocket.

 

I did my twenty plus years in the marine industry and have moved on to another industry that's equally challenging if not more.

 

I have built many foils before for small boats, some used spruce with carbon tows along with glass overlays, most were foam sandwhich construction. I simply asked a question because I thought I could see a different way that wasn't available when I was building boats.

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Word has it the boat is still in the yard and behind on yard bills.

This Mull 30 may come up for sale to cover the yard bills as soon as the title has been transferred to the yard through a lien. If you are a do it yourself'er, maybe less than 5K might get you the boat.

Unfortunately I've been told the owners took all the sails off. But they may surface at Minnies for pennies on the dollar.

The rig looks good, just some work needs doing.

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Word has it the boat is still in the yard and behind on yard bills.

This Mull 30 may come up for sale to cover the yard bills as soon as the title has been transferred to the yard through a lien. If you are a do it yourself'er, maybe less than 5K might get you the boat.

Unfortunately I've been told the owners took all the sails off. But they may surface at Minnies for pennies on the dollar.

The rig looks good, just some work needs doing.

Free is too much!

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Is this a Mull/Donovan/Humbolt 30? What construction material? Does it have a road trailer?

 

It's a Mull 30, it looks like Glass over Wood . It is very wide and does not have a trailer.

It used to be called Sparky, came from the bay area and is now called XS.

 

The boat can be fixed but I think it will get moved somewhere and finish rotting.

 

But like Bob Said, Free is too much. It all depends on what you want. Some like working on boats.

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Update, I was wondering what happened to the boat and found it being moved around on a trailer that looks to be modified  This side does not show the damage as the earlier ones did. Move every 3 days and you do not need to pay storage fees.

She still lives but is probably on life support now. The wood core is probably starting to rot from exposure.

xs.thumb.jpg.4a737db695a036cddcad336c8f94d5c1.jpg

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