The reason lighter cats are safer?

[CatNewBee]

Originally Posted by Sand crab

So this older thread has a few posts about Lagoons having sprayed in vinylester on the exterior of the hills only. I imagine they could have gone all vinylester in the hull construction by now. Can someone point to data by Lagoon that says this is so?
https://www.cruisersforum.com/forums...ns-121282.html

Maybe interesting for you, just to stop the speculations:

https://www.catamaransite.com/refere...nd-composites/

more general reading:
https://www.boats.com/on-the-water/b...erglass-cores/

[CatNewBee]

https://www.lagoon-katamaran.com/index.php?id=582&L=2

[Sand crab]

I read the first 2 links and couldn’t find anything definitive on vinylester on Lagoons. The 3rd link in the last post has this:

• The anti-osmosis barrier systematically created by the use of vinylester type resin on all the Lagoons is a guarantee of durability.

Still vague. I’m not dissing Lagoons just inquiring. If it’s just a barrier coat then it’ seems comparable to Leopard.

[Sand crab]

By comparison Seawind says this about the 1260:

Hull Laminate: Vinyl Ester (Modified epoxy) resin laminate of the hulls between the gelcoat and the foam core. Polyester resin elsewhere.

The resin is the laminate.
https://www.seawindcats.com/seawind-...pecifications/

[Tupaia]

Originally Posted by Sand crab

By comparison Seawind says this about the 1260:

Hull Laminate: Vinyl Ester (Modified epoxy) resin laminate of the hulls between the gelcoat and the foam core. Polyester resin elsewhere.

The resin is the laminate.
https://www.seawindcats.com/seawind-...pecifications/

This seems an odd combination Vinyl ester gelcoat is very durable and glossy and most important for a boat is also almost as water proof as epoxy, why would they use polyester gelcoat?



Vinyl ester gelcoat is often used to make the moulds, cheaper polyester is then used for the structure.



If you are going to use vinyl ester resin then you may as well use Vinyl ester gelcoat.



Vinyl ester resin is more difficult to infuse due to viscosity and has a limited shelf life which is why manufacturers prefer polyester resin for infusion.

[sailjumanji]

Originally Posted by Sand crab

By comparison Seawind says this about the 1260:

Hull Laminate: Vinyl Ester (Modified epoxy) resin laminate of the hulls between the gelcoat and the foam core. Polyester resin elsewhere.

The resin is the laminate.
https://www.seawindcats.com/seawind-...pecifications/

I'm only an amateur on layup, and even own a newer Seawind AND toured the Vietnam factory when it was being built. But can someone explain how you can have resin infused layup with Vinyl Ester limited to one layer and polyester the rest? Guess I should have paid more attention.

[Chotu]

Originally Posted by CatNewBee

Nope. Hulls Vinylester, Deck structures and heads Polyester. No mixing

I see! From what I read above, I was thinking someone was claiming that there were multiple resins in a single panel.


This would make a lot more sense.

[Chotu]

Originally Posted by Sand crab

By comparison Seawind says this about the 1260:

Hull Laminate: Vinyl Ester (Modified epoxy) resin laminate of the hulls between the gelcoat and the foam core. Polyester resin elsewhere.

The resin is the laminate.
https://www.seawindcats.com/seawind-...pecifications/

This actually makes a lot of sense now that I read the link.

So, they use a female mold.

Spray the mold with mold release, PVA or something.

First step, spray the gelcoat into that mold. Don’t use the wax. This leaves the gelcoat ready to bond chemically with the next layer.

Second step, put down the exterior laminate fiberglass.

Third step, press in the core. I forgot what that is. Foam I’m assuming.

Fourth step, arrange the interior Fiberglass.

Fifth step, put in peel ply, enka channel or other type of Raceways for the infusion.

Set up all of your plumbing, get a bag on it, securing the bag to the mold make sure there are no leaks.

This entire time the polyester gelcoat remains reactive, but semi solid.

pull your vinylester through everything doing a normal infusion.

This process would work to make the hulls as they claim.

[Sand crab]

Originally Posted by sailjumanji

I'm only an amateur on layup, and even own a newer Seawind AND toured the Vietnam factory when it was being built. But can someone explain how you can have resin infused layup with Vinyl Ester limited to one layer and polyester the rest? Guess I should have paid more attention.

I think they mean poly on the deck and topsides which are different moulds.
So is gelcoat poly, can it be viny? Or something else?

[44'cruisingcat]

Originally Posted by Sand crab

I read the first 2 links and couldn’t find anything definitive on vinylester on Lagoons. The 3rd link in the last post has this:

• The anti-osmosis barrier systematically created by the use of vinylester type resin on all the Lagoons is a guarantee of durability.

Still vague. I’m not dissing Lagoons just inquiring. If it’s just a barrier coat then it’ seems comparable to Leopard.

Makes sense. You wouldn't need an anti osmosis barrierof vinylester if the actual layup was done in vinylester.

[BigBeakie]

Not necessarily. All vinylesters are not equal. They can be on a spectrum wrt to how close they are to epoxy vs polyester resins.

It's better practice to have the barrier coat a quality epoxy that is formulated specifically for underwater continuous immersion.

Knowing how Lagoon cuts corners on manufacturing costs, they probably select the vinylester with cost, not quality, in mind.

[sailjumanji]

Originally Posted by Chotu

This actually makes a lot of sense now that I read the link.

So, they use a female mold.

Spray the mold with mold release, PVA or something.

First step, spray the gelcoat into that mold. Don’t use the wax. This leaves the gelcoat ready to bond chemically with the next layer.

Second step, put down the exterior laminate fiberglass.

Third step, press in the core. I forgot what that is. Foam I’m assuming.

Fourth step, arrange the interior Fiberglass.

Fifth step, put in peel ply, enka channel or other type of Raceways for the infusion.

Set up all of your plumbing, get a bag on it, securing the bag to the mold make sure there are no leaks.

This entire time the polyester gelcoat remains reactive, but semi solid.

pull your vinylester through everything doing a normal infusion.

This process would work to make the hulls as they claim.

Thanks for that explanation. Yeah they use a female mold for deck, and one for hull. Two massive molds.

[44'cruisingcat]

Originally Posted by BigBeakie

Not necessarily. All vinylesters are not equal. They can be on a spectrum wrt to how close they are to epoxy vs polyester resins.

It's better practice to have the barrier coat a quality epoxy that is formulated specifically for underwater continuous immersion.

Knowing how Lagoon cuts corners on manufacturing costs, they probably select the vinylester with cost, not quality, in mind.

LOL! Thats kind of splitting hairs isn't it? "We use vinylester everywhere, but most of it is very much like polyester, except the barrier coat, which is a vinylester that's a lot like vinylester."

[Sand crab]

44 you crack me up!!!

[Sand crab]

I looked it up and am answering my previous question. Gel coat is available in poly, vinyl or epoxy.