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Old 30-01-2015, 10:20   #31
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Re: Boats coming apart at the toerail...

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Originally Posted by Cavalier MK2 View Post
Fiberglass loses a lot of strength through cycle fatigue. A excellent describtion and lab tested results are in the Gougeon Boatbuilding book available as a free download from the WEST epoxy site. Chapter 3 "Wood as a Structural Material" has these figures graphed for wood, steel, aluminum and glass and carbon. Briefly after a million cycles, accrued over about 4 years of weekend use and cruising, wood has 60% of its strength left, aluminum 40% and glass 20%.
I'll never fly again this those flexing glass skinned wings.
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Old 30-01-2015, 10:45   #32
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Re: Boats coming apart at the toerail...

I love it when these postings get all technical and esoteric. We are likely discussing the difference in life spans of some of these FRP boats of decades. Compared to how long wood boats last (function of structure and maintenance) it is curious. There are some wood boats out there (plank on frame, not the cold molded variety) that, with proper maintenance have lasted over 100 years. And yet, some have lasted on a few years due to neglect.

If someone believes a solid hulled 50 y/o sailboat built in the early days of the resin age will suddenly fall apart like so many straws sprung from a bundle, let us see the pics. Somewhere there is one that has sat in the water and gone thru the loading/unloading cycles that is just ready to pop.

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Old 30-01-2015, 13:31   #33
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Re: Boats coming apart at the toerail...

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When boats spend 95% of their time at the dock, not much stress involved, a few storms a year maybe.
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Old 30-01-2015, 14:05   #34
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Re: Boats coming apart at the toerail...

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Originally Posted by crazyoldboatguy View Post
I love it when these postings get all technical and esoteric. We are likely discussing the difference in life spans of some of these FRP boats of decades. Compared to how long wood boats last (function of structure and maintenance) it is curious. There are some wood boats out there (plank on frame, not the cold molded variety) that, with proper maintenance have lasted over 100 years. And yet, some have lasted on a few years due to neglect.

If someone believes a solid hulled 50 y/o sailboat built in the early days of the resin age will suddenly fall apart like so many straws sprung from a bundle, let us see the pics. Somewhere there is one that has sat in the water and gone thru the loading/unloading cycles that is just ready to pop.


Most 100 year old wood boats have very few original parts left. It only counts as longevity if major repairs are not required. Most wood boats are no longer structurally sound about twenty to thirty years after construction without major repairs, ie some planking.
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Old 30-01-2015, 14:39   #35
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Re: Boats coming apart at the toerail...

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So, this months Sail Mag has an article about a Pearson that was rolled at sea and the side caved in coming completely apart at the hull deck joint... the picture shows the hull caved well in from the deck edge. They survived barely. Not a hurricane or huge storm etc.
This is the third of this type of damage I've heard about over the years, not counting Rebel heart... which may have been a different build construction/situation... unsure. All the boats in question were old. I think most of us believe the Pearsons to be fairly well built boats, not a Westsail, but not a light boat either.
I'm one of those people who believe "where there's smoke there's fire".. so here's the question.
I wonder how badly fiberglass "ages", gets more brittle etc, to the point where it looses a lot of strength?
Thinking about it, I've salvaged a couple old dingys that sat outside unused for a long time, turns out they were so brittle, that the cloth seemed to have less resin and you could easily put your foot right thru the hull.
I wonder if anyone has ever done strength testing on old fiberglass panels vs new of the same layup?
I would have the same question, I almost think UV takes it toll. Pearson I believe made a good boat. I seems to me the hull and deck where bedded and screwed together. Not sure what bedded means or if it meant structurally of just water tight.
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Old 30-01-2015, 14:40   #36
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Re: Boats coming apart at the toerail...

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I'll never fly again this those flexing glass skinned wings.
? Aren't most airplane wings aluminum skinned? On the new composite birds they use carbon fiber to avoid the cycle degradation problem. Boeing and Airbus put their faith in the tests....

My tri wings are skinned with ply, don't flex, glass is used for surface abrasion. Glass, carbon fiber, kevlar , polypropolene and dynel all of several different types from uni to weaves are used in various places depending on requirement, surface abrasion to load reinforcement etc.....
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Old 30-01-2015, 14:49   #37
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Re: Boats coming apart at the toerail...

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? Aren't most airplane wings aluminum skinned? On the new composite birds they use carbon fiber to avoid the cycle degradation problem. Boeing and Airbus put their faith in the tests....

My tri wings are skinned with ply, don't flex, glass is used for surface abrasion. Glass, carbon fiber, kevlar , polypropolene and dynel all of several different types from uni to weaves are used in various places depending on requirement, surface abrasion to load reinforcement etc.....
That was just in jest. Yes some wings had fiberglass skins and are probably still flying I can remember Lockheed putting them in the kiln. If the wing stops flexing grab your chute.
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Old 30-01-2015, 14:54   #38
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Re: Boats coming apart at the toerail...

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Originally Posted by nimblemotors View Post
When boats spend 95% of their time at the dock, not much stress involved, a few storms a year maybe.
I have seen a few marinas where the boats are in motion almost constantly. They rock back and forth alarmingly in my view. Must place tremendous cycle stress loads on their rigging, keels and rudders. Just while sitting there, year after year.
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Old 30-01-2015, 14:59   #39
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Re: Boats coming apart at the toerail...

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Most 100 year old wood boats have very few original parts left. It only counts as longevity if major repairs are not required. Most wood boats are no longer structurally sound about twenty to thirty years after construction without major repairs, ie some planking.

Yes, but if you read the comments from those who opine that the FRP boats are bound to deteriorate no matter what you do - just by the aging process - tell me how you prevent THAT from happening. At least I can put some red lead paint on the old wood. How does one get INTO the fibers themselves, buried deep in the laminates, to prevent the unpreventable?
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Old 30-01-2015, 15:18   #40
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Re: Boats coming apart at the toerail...

Anything made by man will fail sooner or later & as they say **** happens.


I think that bulkheads on most of the older boats are there to provide structural integrity & given the fact the bulkhead on this boat got deposited to the opposite side of the hull, IMHO tells all. Maybe after years of water intrusion it rotted away where it was glassed to the hull.


I know the bulkheads on my Sabre were like this. Pretty solid where you could see them. Down at the bulkhead to hull joint, where no one goes unless you're ripping a boat apart, I could push a screwdriver thru them. I can so how getting hit by a big wave & a failing bulkhead could stove the hull in.


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Old 30-01-2015, 15:18   #41
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Re: Boats coming apart at the toerail...

All these concerns about fiber glass boats breaking apart at sea due to age are a bit like that thread on Ebola coming to town, whole bunch of talk by the naysayers followed by nothing to worry about. I'd worry more about the new boats because of their light weight construction if I was a worrier but I'm not so I don't worry about the old stuff or new stuff.
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Old 30-01-2015, 15:36   #42
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Re: Boats coming apart at the toerail...

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Originally Posted by crazyoldboatguy View Post
Yes, but if you read the comments from those who opine that the FRP boats are bound to deteriorate no matter what you do - just by the aging process - tell me how you prevent THAT from happening. At least I can put some red lead paint on the old wood. How does one get INTO the fibers themselves, buried deep in the laminates, to prevent the unpreventable?
I doubt you can buy red lead. I'm not saying you are wrong. I'm not sure some of the new laminates won't go before the old heavy ones.
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Old 30-01-2015, 15:41   #43
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Re: Boats coming apart at the toerail...

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I read the description written by the owner of the Pearson Triton of what happened during the incident that left his boat essentially destroyed.

The owner described having passed by a river delta where much debris was seen in the water. Tree trunks, branches and much man made stuff was seen floating around. It was only a short time later, during heavy weather, that the boat suffered the damage. It appears from the pushed in section of the hull that the boat made have struck something which could very well have caused the damage seen in the photo.

Late last year my 1962 Pearson Triton broke loose from her mooring and ended up on a rock beach. She pounded on that beach during heavy surf for at least 8 hours before she was lifted off. The damage was located in the same area, just below the chainplates, only at the waterline, not the hull/deck connection. She suffered no more damage than some chipped gel coat.

The boats were built like brick shithouses. I vote that the boat hit an object at or near the surface during heavy weather.
If you read it then you must have seen the picture of the damage. It sure doesnt look like this Pearson was "built like a brick sh*thouse" looking at the edges of the torn fiberglass.
They were trying to make headway against the wind and down to a triple reefed main that they were loosing stitching on even then. "every passing wave soaked us to the bone". They reported large seas, but saw the one huge wave that rolled the boat over. Not sure if they went 360 or not. The wave that rolled the boat caved the side in. Based on pics I'm not sure this was a terribly well kept boat.
But well kept or not shouldn't have much to do with the strength of the glass at the deck/hull joint.
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Old 30-01-2015, 15:42   #44
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Re: Boats coming apart at the toerail...

I have a tub of red lead powder in my shop as we speak. I use it to make my own red lead paint. Google is wonderful - found a supplier in Canada. Bought some white lead powder as well. Since I probably won't be using canvas to cover my house top, I may not need that.

Again, the folks posting here got off into an interesting tangent - that is what I was responding to. Some of the comments got off into the esoteric nature of minutiae involving resin/age/heat/light/etc of a type that amuses me. Again, it happens in some of these streams where the theory bumps up against reality.
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Old 30-01-2015, 15:49   #45
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Re: Boats coming apart at the toerail...

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FRP definetly degrades with age. In essence it never stops curing. At some point it gasses off all of it's plasticisers and becomes brittle. Depending on the quality of layup and resins this may take decades. Some boats Willard made for the USN actually tested stronger after 20 years (See this months edition of Professional Boat Builder magazine) but eventually the Willards too will degrade.

I see this off-gassing issue often in fire damage claims. Often the neighbouring vessels show no more than soot but the structure is seriously degraded and brittle due to super fast curing induced by the heat.

My opinion .... we are just entering the age of brittle, degraded FRP and will see much more of this in older boats.
This is what I was trying to get to in my posting this subject, I have been a proponent of older boats (mostly due to many having heavy scantlings), but ..... I'm starting to wonder.
Sure most boats out there will do fine, the key is don't get rolled or exposed to too much pounding!
The Cheoy Lee that came apart at the Hull/deck joint off the coat of Oregon years ago was being pounded pretty hard on the beam in heavy seas as I remember.

Not sure about cycle fatigue being the culprit, it not all about # of cycles, but also about how far the material is cycled. In the case of sailboats... heck it doubt most boats are cycled very far at all....
ie: take a wire coat hanger and bend it about 1/8"... do think cycle fatigue will ever effect it much?
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