Buying Newest, Latest Version or Used with Similar Performance . . .

[beautygab]

Assuming your not rich but wants a lightweight small and handy trimaran like this one:

SeaCart 26 Trimaran GoPro High definition (HD) Sailing - YouTube

–Would you consider it worth it to go brand new and assume that the benefits of fresh new plastics and fibers (epoxy + carbon fiber) outlasts the negative aspects that come with time on all fiber composites...such as creep in form shape, possible small cracks, aging of polymer,...?

In other words; – How long can you assume a fiber composite lasts? I mean steel bicycles lasted almost forever, as compared to the carbon fiber bicycles that currently are replaced every 3 stages in Tour de France because of deformations under load.

When is the break point for a multihull? 3 years old still worth buying because it last for another 10...? 20 year... can that be regarded as end of use?

I figure this must be a question everyone asks themselves since it's not really as affordable to replace a hull as a starting engine in a car...

[Sail IC]

The weak point of a laminate is typically the resin and not the fiber.

Polyester is actually a fairly bad resin for glassfiber (and carbon) as the resin is much stiffer (breaks at shorter elongilation) than the fiber itself. Under strong loads, a polyester laminade develops microcracks and the strength goes down and it gets heavier.

The key in your boat is that its made of epoxy which is much softer and enable the fiber to take up the load. Make a Epoxi/carbon sandwich construction, and you end up with a very strong and long lasting laminate. The key to look out for is delamination, but that should not be an issue on a well built boat.

To give some practical examples. In 505, a very competitive racing dinghy (just below olymic level). When the boats were made out of polyester, the competitive life was around 2-3 year. When made out of Epoxi, a 15 year old boat has won the world championship, and this in a very competitive class.

My current boat has a carbon mast which is 10 years old. Its as good as new.

I have no experience of the Seacat (very cool boat btw), but if its well made and not a superlight construction pushing beyond the limits (production boats rearly are), I see no reason why it shouldn't last well over 10 years being as good as new.

[beautygab]

Yes, indeed the structural build must make a difference in terms of over-sizing for margin on strength, ..and indeed epoxy is as said much better than the polyester resins ..but any fiber composite must have its life-time.

The brand new military boats in epoxy/carbon fiber we used during my military service were fine on taking hits (from loading stuff on and off) the first few years, but the 10+ year broke like eggshells on a hit..even if they seamed to be perfectly fine (before).