How tough is the vinylester sandwich used in Nacra 500 and 570s? How does it hold up to beaching?

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John

Nacra 5.0
CT
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If the hulls are like the inter 20... and you love your boat and want it to last....get some beach wheels. I beach my boat but i lift the bows and carry it as far up as i can and gently set them down. Inland lakes so no tide or high waves. Depnds on how corse the sand is.



Edited by schoen.steve on Aug 19, 2018 - 09:22 AM.

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Steve
Nacra Inter 20
Okemos Michigan
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Not a Nacra guy, but the 500 and 570 seemed to be built with rec sailing in mind with the skegs and boomless rigs so I would assume they put some durability in those hulls.

I've never seen a Nacra in person, are they not made of fiberglass?

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Marty
1984 Hobie 16 Redline Yellow Nationals, "Yellow Fever"
Opelika, Al / Lake Martin
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Vinylester foam sandwich construction is a type of fiberglass construction. I’ve heard vinylester is slightly superior to polyester in strength and water absorption. Also heard a little more toxic and Enviromentaly sensitive to work with. Repairs may present other challenges as well but it seems similar to polyester in many ways, which I think is what most of our boats on this forum are made of



Edited by jalex on Aug 19, 2018 - 06:50 PM.

Epoxies, Vinylesters and Polyesters Explained - MAS Epoxies

Epoxies represent some of the most versatile resins available to the composite manufacturer. Generally, in all categories of work, the builder/repairer will realize the greatest degree of bond strength, waterproofing and toughness with well formulated epoxies.

Vinylesters
Vinylesters represent a resin development step in the right direction. While still utilizing a polyester resin type of cross-linking (i.e. peroxide cured). These hybrid resins are toughened with epoxy molecules within the backbone. Shrinkage is less of a concern with vinylesters and prerelease of the part from the mold is reduced. The toughening effect of the resin modifications makes for a better resistance to micro fracturing and some of the secondary functionality of the backbone assists in adhesion to substrates. Vinylesters are capable of forming secondary bonds around 500 PSI (MAS Epoxies 2000 PSI). Resistance of vinylester resin to moisture is good and some commercial barrier coatings have been marketed utilizing this resin family. The down side of the vinylesters include sensitivity to mixing, handling, atmospheric moisture and temperature sensitivity (sometimes it just will not cure).

Polyesters are one of the least expensive resins available to the FRP boat builder utilizing female tooling in the form of a mold. Polyester has the advantage of being extremely inexpensive when compared with other thermoset resins i.e. vinylesters and epoxies. If the upside is cheap pricing, the down side includes poor adhesions, high water absorption, and high shrinkage. Polyester resins are only compatible with fiberglass fibers.

https://www.jamestowndist…al/document.do?docId=495

Foam sandwich is super strong, but dents (compression damage) very easily. On many boats the hulls are only one layer of glass on outside, foam in middle, and one layer of glass on inside. The foam creates an I-beam like structure out of the two layers of glass, which makes it very strong. However, even dragging a round bottom hull over a small golfball-sized stone on the beach could leave a nasty long compression dent along the bottom.



Edited by traphappy on Aug 20, 2018 - 10:18 AM.

This greatly depends on which Nacra you're discussing.
Most of our boats are Polyester including the 460,500, and 570 which also have a layer of G10 on the bottom of the skeg which can be replaced if it's really worn down. We also recently just introduce a replaceable G10 "shoe" for resorts for ultimate durability.
These 3 boats are essentially as durable as a polyester Hobie Cat.
The older versions have a durable thick laminate schedule but don't feature the reinforced skeg.

Our modern race boats are durable but intended for a different purpose. They are thinner laminate schedule all around which means if you don't treat them well they won't hold up. Running them up a rocky beach or putting a trapeze hook into the side won't end well!
The Nacra 17 and 20 are carbon/epoxy and the F18 was recently changed to epoxy.

Hope this helps!

Hey Nacrasailing, I have a 2000 NACRA 500 and sail it most of the time off the beach in Daytona FL. I do use beach wheels while moving it around but hitting the shore line in surf does wear down the skegs. I am interested in this G10 shoe you are referring to. Where can I get more information on this product. Thanks.

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Pete
2001 NACRA 450 SOLD
2000 NACRA 500 TOTAL LOSS
2004 NACRA INTER 20 SOLD
2016 NACRA 500 Sport
DeLand, FL
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