Lagoon Cat smashed in Thailand

[minaret]

Originally Posted by 44'cruisingcat

Not as long as there is a beach somewhere nearby.

The area of your hulls most likely to suffer impact (the bottom) is also the area most likely to be sitting on sand when you beach the boat. Unless you have a way to jack up the boat, you are unlikely to make a repair this way. Especially in a single tide. A mono is actually much better off careening, as you can actually get to the whole bottom.

[smj]

Originally Posted by minaret

The area of your hulls most likely to suffer impact (the bottom) is also the area most likely to be sitting on sand when you beach the boat. Unless you have a way to jack up the boat, you are unlikely to make a repair this way. Especially in a single tide. A mono is actually much better off careening, as you can actually get to the whole bottom.

Probably 95% of cruising cats have keels and when beached the entire bottom will be accessible for repairs. Also if it's a well designed cat, the keels will be sacrificial and attached to the hull after the hull was laid up. This means if the keels are damaged the hulls won't be compromised.


Sent from my iPad using Tapatalk

[minaret]

Originally Posted by smj

I agree that balsa can wick moisture, but a well built resin infused vacuum bagged balsa hull should have minimal problems with water spreading through the core if done correctly. When people hear balsa core, I think they think of the older boats and the problems with their balsa cored decks.


Sent from my iPad using Tapatalk

"Should have" lol. I've heard that from a lot of very sad owners trying to understand why their boat is rotten inside.


As an example, I'll mention the Cascadia incident. I was on the build from the start myself. All vacuum bagged balsa core, above and below the waterline, bagged in epoxy. 12.8 million to complete, all bagged carbon. First summer after launch they took her to Alaska for shakedown and the "professional" skipper put her on a rock in Prince William at fourteen knots. Damage was severe gouges through the outer skin, which in this case also had a layer of cold molding. They thought it would be OK to bring the boat back down to us for repair, instead of immediately hauling her and trucking her down. A little over a week later they made it back and we hauled. All of the balsa below the waterline ended up being replaced, at the cost of several million dollars. It was all wet. Not saturated, but wet. Building a boat out of a sponge like material and expecting it not to get wet is stooopid.

[minaret]

Originally Posted by smj

Probably 95% of cruising cats have keels and when beached the entire bottom will be accessible for repairs. Also if it's a well designed cat, the keels will be sacrificial and attached to the hull after the hull was laid up. This means if the keels are damaged the hulls won't be compromised.


Sent from my iPad using Tapatalk

Let's see some pics of those cats beached, shall we?



Most of the ones I've seen the keels sink into the sand, and are very short in the first place, giving at most six inches of clearance. Good luck doing a hull repair in a single tide like that! Especially if it's a bad one.

[smj]

Sent from my iPad using Tapatalk

[noelex 77]

Originally Posted by colemj

In most core builds, the outer skin is thicker than the inner skin.

Mark

I will bow to your better knowledge Mark.

In the typical damage you see being repaired in a boatyard the outer skin is more often seen. It can be very thin.

Structurally it does not make sense to me to make the outer skin thicker unless the gel coat, which has little strength, is a significant portion of the thickness, but perhaps some cats are constructed with abrasion resistance in mind?

Maybe Minaret can help.
What is the typical thickness of the fibreglass inner an outer skin in a production cat?

[smj]

Sent from my iPad using Tapatalk

[minaret]

Originally Posted by noelex 77

I will bow to your better knowledge Mark.

In the typical damage you see being repaired in a boatyard the outer skin is more often seen. It can be very thin.

Structurally it does not make sense to me to make the outer skin thicker unless the gel coat, which has little strength, is a significant portion of the thickness, but perhaps some cats are constructed with abrasion resistance in mind?

Maybe Minaret can help.
What is the typical thickness of the fibreglass inner an outer skin in a production cat?

The outer skin is always thicker in all boats.

[smj]

Originally Posted by minaret

"Should have" lol. I've heard that from a lot of very sad owners trying to understand why their boat is rotten inside.


As an example, I'll mention the Cascadia incident. I was on the build from the start myself. All vacuum bagged balsa core, above and below the waterline, bagged in epoxy. 12.8 million to complete, all bagged carbon. First summer after launch they took her to Alaska for shakedown and the "professional" skipper put her on a rock in Prince William at fourteen knots. Damage was severe gouges through the outer skin, which in this case also had a layer of cold molding. They thought it would be OK to bring the boat back down to us for repair, instead of immediately hauling her and trucking her down. A little over a week later they made it back and we hauled. All of the balsa below the waterline ended up being replaced, at the cost of several million dollars. It was all wet. Not saturated, but wet. Building a boat out of a sponge like material and expecting it not to get wet is stooopid.

So you were part of the build of the boat with the failed core?

[noelex 77]

Originally Posted by minaret

The outer skin is always thicker in all boats.

OK thanks. Sorry for the misinformation. What are typical thicknesses of the skin?

[smj]

Originally Posted by minaret

Let's see some pics of those cats beached, shall we?



Most of the ones I've seen the keels sink into the sand, and are very short in the first place, giving at most six inches of clearance. Good luck doing a hull repair in a single tide like that! Especially if it's a bad one.

Nice edit to try to make the save!


Sent from my iPad using Tapatalk

[sparau]

Originally Posted by minaret

"Should have" lol. I've heard that from a lot of very sad owners trying to understand why their boat is rotten inside.


As an example, I'll mention the Cascadia incident. I was on the build from the start myself. All vacuum bagged balsa core, above and below the waterline, bagged in epoxy. 12.8 million to complete, all bagged carbon. First summer after launch they took her to Alaska for shakedown and the "professional" skipper put her on a rock in Prince William at fourteen knots. Damage was severe gouges through the outer skin, which in this case also had a layer of cold molding. They thought it would be OK to bring the boat back down to us for repair, instead of immediately hauling her and trucking her down. A little over a week later they made it back and we hauled. All of the balsa below the waterline ended up being replaced, at the cost of several million dollars. It was all wet. Not saturated, but wet. Building a boat out of a sponge like material and expecting it not to get wet is stooopid.

I thought that construction method was end grain blocks with epoxy in between each block, shouldn't the epoxy have stopped the water ingress at each block end ?

Is this a failure of the build rather than of the method ?

I seem to remember reading duracore stating that in their sales pitch, that water intrusion is limited to the affected areas.

[minaret]

Originally Posted by noelex 77

OK thanks. Sorry for the misinformation. What are typical thicknesses of the skin?

I've seen extremely wide variation in laminate thickness and quality, in boats both cored and solid. The Lagoon depicted earlier is a great example of a boat with an extremely thin single skin.

[smj]

Originally Posted by sparau

I thought that construction method was end grain blocks with epoxy in between each block, shouldn't the epoxy have stopped the water ingress at each block end ?

Is this a failure of the build rather than of the method ?

I seem to remember reading duracore stating that in their sales pitch, that water intrusion is limited to the affected areas.

+1


Sent from my iPad using Tapatalk

[minaret]

Originally Posted by sparau

I thought that construction method was end grain blocks with epoxy in between each block, shouldn't the epoxy have stopped the water ingress at each block end ?

Is this a failure of the build rather than of the method ?

My point is, even in a full vacuum bagged epoxy construction, some voids are inevitable. Good luck finding an affordable boat that uses such methods, best you are likely to find is infused. I've seen the same over and over, from many different builders. And even from myself!