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02-02-2015, 16:43
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#76
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Registered User
Join Date: Aug 2006
Location: Skagit City, WA
Posts: 25,453
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Re: Boats coming apart at the toerail...
Quote:
Originally Posted by thomm225
So one Pearson Triton out of more than 700 built had a problem.
Are there lots of other reports of that boat having a similar problem?
Also, it looks like the boats were built differently at different times and sites.
Construction
Although it was a production boat, individual Tritons appear to vary widely in terms of construction. In general they have the thicker, tougher and less sophisticated hulls of the earlier fiberglass production boats. Many of the East coast boats have balsa cored decks where the majority of the West coast boats have decks of solid fiberglass but this isn’t definitive. Ballast in the early days was iron encapsulated in the keel but switched to encapsulated lead in later years.
The Pearson Triton 28 Sailboat : Bluewaterboats.org
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What we do know is ONE took a hard knockdown that rolled it... or nearly did. That one came apart. We have no idea how many have been rolled , but my guess not many... as not many sail that small a boat in big oceans and have an event like this.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard
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02-02-2015, 16:46
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#77
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Registered User
Join Date: Jul 2012
Location: Caribbean
Boat: C&C 48 Custom
Posts: 26
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Re: Boats coming apart at the toerail...
Quote:
Originally Posted by toddedger
Besides there being very few mechanical fasteners in the outward flange joint one should consider the glass reinforcement. When you come back and add glass to the deck and hull joint after they both have already set up, it doesn't stick very well.
As a rule polyester resin is a poor adhesive. Unless the two sides were ground with abrasives to add tooth for a mechanical bond there isn't much strength. That's why we use mostly epoxy to make structural repairs on fiberglass boats these days.
So while the hull may be thick and tough, if you want a brick shithouse than you you need a better deck to hull joint. Also the bulkheads need to go in quick while the layup is still green.
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Ideal but not a realistic expectation of old production boats to have all structural components bonded when still green. Also even with quality construction it's hard to say what a 50+year old boat has been through, there are no guarantees on any boat.
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02-02-2015, 17:02
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#78
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Registered User
Join Date: Sep 2012
Posts: 5,983
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Re: Boats coming apart at the toerail...
Large waves are often very distructive. When a boat is rolled or falls off a wave it can do a lot of damage to very well built boats. Its not uncommon to have ports implode in situations like this. These days very few sailors are ever exposed to something like this because the boats are so much larger and length makes them harder to roll but every now and then it happens.
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02-02-2015, 17:18
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#79
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Registered User
Join Date: Aug 2006
Location: Skagit City, WA
Posts: 25,453
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Re: Boats coming apart at the toerail...
Quote:
Originally Posted by toddedger
Besides there being very few mechanical fasteners in the outward flange joint one should consider the glass reinforcement. When you come back and add glass to the deck and hull joint after they both have already set up, it doesn't stick very well.
As a rule polyester resin is a poor adhesive. Unless the two sides were ground with abrasives to add tooth for a mechanical bond there isn't much strength. That's why we use mostly epoxy to make structural repairs on fiberglass boats these days.
So while the hull may be thick and tough, if you want a brick shithouse than you you need a better deck to hull joint. Also the bulkheads need to go in quick while the layup is still green.
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At least one builder I spent a lot of time at joined the hull and deck with the hull still in the mold. He put the main bulkheads and a lot more in first.
(When you pull a bare hull out of the mold it looses shape.) If I remember right once the interior stuff was in he pulled the hull a few inches out of the mold to put the deck on.
But yeah... the glass layup needs to be green or prepped for sure. My guess is most inside glassed hull to deck joints are mostly for leak stoppage.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard
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02-02-2015, 17:21
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#80
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Registered User
Join Date: May 2011
Location: San Diego CA
Boat: Liberty 458
Posts: 2,205
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Re: Boats coming apart at the toerail...
Quote:
Originally Posted by Cavalier MK2
Keep telling yourself this stuff. Time will tell and you may may get lucky!
Most boats do spend most of their time at the dock so they won't be experiencing many cycle loadings, just the degredation from immersion and sunlight. Bigger waves = more cycles as do stronger winds. Saying results of tests are meaningless doesn't make them so. The seas will be providing the unbiased tests in the long run, not a class I'd like to skip the homework in.
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Test results are meaningless without context. Decades of engineering using the scientific method and empirical data is proof enough for me.
The OP posted loss of strength percentages that he was trying to relate to actual failures. Those values don't correlate to vessels in service. What were the test conditions? Gel coat, no gel coat, liquid type, pH, temperatures, loadings, etc. It's a brave person who makes correlation judgements with insufficient information.
Unfortunately we have almost no reliable in service data for recreational boats to correlate to simple test data.
Getting back to the OP's original question. Degradation of fibreglass hulls to moisture adsorption is at best a second order issue. There is good data available for fibreglass chemical tanks which is interesting at best. It shows us that a fibreglass composite rarely fails from moisture adsorption when engineered properly.
How many yachts sank because the fibreglass hull broke up because of this failure mode? None that I can think of. Wooden boats? Lots.
Sent from my SM-N900T using Cruisers Sailing Forum mobile app
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04-02-2015, 16:20
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#81
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Registered User
Join Date: Jan 2006
Location: North Carolina
Boat: 44 footer
Posts: 953
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Re: Boats coming apart at the toerail...
Fair disclosure: I chopped the cockpit out of my Triton 5-6 years ago, and left it uncovered in the sun and no longer trusted the resin, so she got scrapped out rather than rebuilt.
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That's a west coast Triton, it has molded in coaming boards and out-turned hull flange.
They weigh close to a thousand pounds lighter than the east coast versions.
The externally ballasted tritons weighed more than the internally ballasted boats that made the transition around #300. A few years back, one of the lists documented the unloaded Stem to water height, of the different models. Can't remember where I saw it, but there is a pretty wide variance in the build weight.
This is a half section cutaway of an east coast triton, with some measurements for the interested.
I read about a Bristol 27 on earlier pages, they are no Triton... I was the saw man on scrapping one off a friends trailer, and it was down in a pile in less than 3 hours. The Triton took a day and a half. Both boats were stripped, no interior, no engine and rig was already down. Main and lazarette bulkheads only.
You can't cut a Triton with a skill saw, and it will wear the teeth off 6-8 tooth lenox blades. The only thing that works well are carbide abrasive sawzall blades.
I couldn't carry by myself, any piece of the hull larger than 4x3 foot square. It took me and two other guys to load the first 3 feet of the bow of the Triton on the trailer.
The Bristol I could carry a 3x8 foot section at a time, and could drag the bow around by myself...
Anecdotal, but if a Triton couldn't take that blow I don't see anything short of a steel boat taking it any better.
Cheers,
Zach
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04-02-2015, 16:53
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#82
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Marine Service Provider
Join Date: Nov 2008
Location: Port Credit, Ontario or Bahamas
Boat: Benford 38 Fantail Cruiser
Posts: 7,047
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Re: Boats coming apart at the toerail...
Quote:
Originally Posted by Zach
Fair disclosure: I chopped the cockpit out of my Triton 5-6 years ago, and left it uncovered in the sun and no longer trusted the resin, so she got scrapped out rather than rebuilt.
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That's a west coast Triton, it has molded in coaming boards and out-turned hull flange.
They weigh close to a thousand pounds lighter than the east coast versions.
The externally ballasted tritons weighed more than the internally ballasted boats that made the transition around #300. A few years back, one of the lists documented the unloaded Stem to water height, of the different models. Can't remember where I saw it, but there is a pretty wide variance in the build weight.
This is a half section cutaway of an east coast triton, with some measurements for the interested.
I read about a Bristol 27 on earlier pages, they are no Triton... I was the saw man on scrapping one off a friends trailer, and it was down in a pile in less than 3 hours. The Triton took a day and a half. Both boats were stripped, no interior, no engine and rig was already down. Main and lazarette bulkheads only.
You can't cut a Triton with a skill saw, and it will wear the teeth off 6-8 tooth lenox blades. The only thing that works well are carbide abrasive sawzall blades.
I couldn't carry by myself, any piece of the hull larger than 4x3 foot square. It took me and two other guys to load the first 3 feet of the bow of the Triton on the trailer.
The Bristol I could carry a 3x8 foot section at a time, and could drag the bow around by myself...
Anecdotal, but if a Triton couldn't take that blow I don't see anything short of a steel boat taking it any better.
Cheers,
Zach
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Weight has nothing to do with strength. A very high resin ratio will provide weight while making for a very brittle laminate.
Excessive resin ratios were very common in that era.
__________________
If you're not laughing, you're not doin' it right.
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04-02-2015, 17:20
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#83
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Registered User
Join Date: Jan 2006
Location: North Carolina
Boat: 44 footer
Posts: 953
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Re: Boats coming apart at the toerail...
You are absolutely right.
Though I am laughing about resin rich laminates when the top right picture is dry as a bone...
She was 13 layers of alternating mat and woven at her cut-water. Heavy.
Zach
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05-02-2015, 08:02
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#85
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Marine Service Provider
Join Date: Jun 2012
Location: near Lake Erie
Boat: 1984 Catalina 22, 2005 Carolina Skiff 24, 1989 BW Outrage 19, BW SS 15
Posts: 546
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Re: Boats coming apart at the toerail...
The hull-to-deck joint of the Pearson Triton is a known weak point.
From "The Restoration of the Glissando:"
The toerail on the Triton is molded as in integral part of the deck structure, and is where, from beneath, the hull and deck are fiberglassed together. The molded portion is hollow, and fiberglass cloth forced into the hollow from beneath is used to secure the hull and deck together. In most places, there is a void between the molded toerail and the tabbing that is secured beneath. This can lead to breakage and damage should an impact occur, as was the case on Glissando.
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