The myth of aging fiberglass

[dlandersson]

The myth of aging fiberglass - if true. Anyone?

[kurz]

what do they say in short word?

[OverEasy]

Nice Article! Thanks for posting it DiAndersson!

Summary:
While it’s a bit wordy it talks well about how a good older fiberglass boat hull that has been maintained can last nearly forever.
Particularly if it was a resin and fabric construction vs. a chopped fiber construction.
The other stuff like embedded wood core balsa and plywood are the aspects that could be of concern as they can degrade if moisture has penetrated them.

The engines and surface hardware, replaceable stuff, are the “wear out” stuff that degrades over time.
But a good fabric layup fiberglass hull from 20-30 years ago can be just as, if not stronger than, a new chopped fiber hull.

The article goes on to talk about the new boat depreciation aspects and how that rate flattens out the older the good condition boat has been around. Buy new and the rate is high for the first years…but that general common sense.

The article also recommends the use of a qualified boat surveyor, which if you can find one, is a great idea when buying an older boat.

The ‘Catch 22’ is this article really only deals with the hull…. There is often a lot more than just a hull when buying a boat.
A lot more! Think engine, trailer, fittings, cushions, trim, sails……

So if one wants to or is ok with the repair/replace/refurbish aspects of the ‘other $$$ stuff’ that makes a boat usable, the age of a good well maintained layup fiberglass hull isn’t a limiting factor.

So if you start with a used layup fiberglass boat in good condition you have a great starting point.

Best Regards,
Over Easy

[Ixneigh]

I sure have a lot of reservations about these 60 plus year old hulls Ive seen on craiglist and places. Just how long is that clever concoction of hydrocarbons and silica fibers going to last in the constant motion of the ocean?

Ix

[kurz]

ok, and where are our and

Good old boats or cheep new ones?

Is there some wood anywhere inside the structure?

[kmclemore]

There is definitely wood in the structure of some of the Macgregor boats. However, all of the wood is well above the waterline. As such, as long as the boat is in reasonable shape, that wood should never really rot. That being said, sometimes it’s only balsa wood, so it’s not exactly very strong stuff. It’s just there as a stiffener and to provide structure for building box sections, so in many cases if the wood was gone altogether, the box section of fiberglass would still be just about as strong. I’ve never heard of a Macgregor boat being taken off the water and being scrapped because of rotten wood.

Other boats, like a lot of power boats and runabouts, have plywood stringers bonded to the inside of the hull, and they support a plywood floor. This is an extremely common building technique from the advent of fiberglass boats to even the current day. When these stringers rot, it is supreme pain in the butt to try to replace them. Often when they’ve perished it means scrapping the boat, since the time and cost to replace them often an exceeds the value of the boat.

As to the longevity of the polymers in fiberglass, I’m not sure there has ever really been a limit on the lifespan. There are even fiberglass cars that are still on the road today that were some of the very first fiberglass vehicles, and they’re holding up just great. So, although there may be a lifetime, we haven’t hit it yet as far as I know.

[dlandersson]

My understanding is that Macgregors were built with long strand fiberglass ccomstruction - which was more expensive and longer than chopped short strand. Roger was asked about this and he made the point that Macs were built with an understanding of the strength of fiberglass when designed/engineered correctly.

Key aspects of MacGregor fiberglass construction include: (Google AI)

Hand-Laid Fiberglass: To ensure quality and control over thickness, MacGregor used hand-laid fiberglass rather than "chopper guns," applying layers of woven roving to create strong hulls.
Solid Hull Construction: The hulls are made of solid, uncored fiberglass to minimize weight and allow for easy trailing.
Deck Structure: Older models often used balsa-cored decks, while newer models (like the 26M) adopted solid fiberglass, U-shaped beams filled with foam for stiffness.
Hull-to-Deck Joint: The hull and deck are typically bonded and through-bolted, often with foam weather-stripping to seal the seam.
Internal Liner: A fiberglass inner liner, forming benches and tanks, is laid into the hull while wet, providing structural support, though it can limit access to the inner hull.
Water Ballast System: A defining feature, the fiberglass hull is designed to hold water for ballast, reducing weight for trailering.
Reinforcement: Extra fiberglass layers are added to high-stress areas like the chainplates, keel/centerboard, and transom.

ok, and where are our and

Good old boats or cheep new ones?

Is there some wood anywhere inside the structure?

[rsvpasap]

This topic has been discussed on this site. By the late 1990s, Macgregor no longer used any type of wood coring. By the the end of 1999, the only wood was in the door to the head and the steps to the companionway ladder.





viewtopic.php?p=251628&hilit=Core+Wood+Factory#p251628

ok, and where are our and

Good old boats or cheep new ones?

Is there some wood anywhere inside the structure?

[Ixneigh]

The transom on my M is wood cored. I very carefully sealed the old bolt holes from the defunct etect motor with fiberglass patches because the mechanics just used epoxy putty which I deemed insufficient. The '72 Venture 22.2 I had before I purchased my current boat, had wood cored stringers, and some structural plywood interior bulkheads. That boat, though not particularly well cared for when I got her, was in excellent structural condition. That boat endured severe misuse, and even a hurricane, after I sold it.
The only case I have personally seen of structural failure, was a 25' which had cracking of the hull along the veeberth edges from "hardspot" stressing. The owner routinely sailed that to the bahamas and had to repair the cracks on a beach somewhere.

Ix