How Long Can Old Fiberglass Last ?

[pdnervo]

Hi, gonna buy a used sailboat prob 35 to 42 ft.... but im curious how long will fiberglass last... i know it loses its luster... but how about its general life expectancy...lots of boats for sale in the 1970's at cheap prices but will they last.... tks ur ans....

[Sailmonkey]

We don't know yet, some old boats have died an untimely death some young boats have died an untimely death........

[Blue Stocking]

Bluestocking is 45yrs old, and in better shape structurally than some of the newer kids around her in the yard.
I know of a few at 50yrs.

[Southern Star]

Its not the fiberglass that is losing its luster, it is the gelcoat which typically covers it as a finishing coat. Fiberglass can probably last forever if properly layed-up, finished and maintained (although after about 10 years it will likely need to painted, or refinished with gelcoat). Nevertheless, in terms of the structure, those are still HUGE ifs.

Many boats will suffer osmotic blistering below the waterline, which can be a time-consuming and expensive repair. Some is largely cosmetic, although if left unattended, it will become structural. Many boats will also suffer delamination if water has been allowed to permeate the core (and yes, virtually all FRP boats have a balsa, or foam core in the decks, most all in the hull above the waterline and many below). This is a structural issue and repairs are even more time-consuming and expensive.

Yes, these things can be repaired and many boats with proper repairs are more sound/durable than they were originally (especially if the bottom was peeled and covered with an epoxy barrier coat, which is less water permeable than gelcoat; or, in the case of deck delamination, had the outer or inner glass laminate removed, the core replaced, and new glass laid over top with all machine screws/bolts 'potted' with epoxy before bedding in order to stop water migration into the core.

The end result - regardless of the age of the boat, get a good independant surveyor.

Brad

[hellosailor]

"but will they last"
They will last as long as it takes ice to melt.

Which is to say, it all depends on how you keep it.

If you're planning to buy an old boat, plan on getting a survey. Yes that costs money, but you can lose far more than the money you spend on a boat, if it has to be condemned and hauled away as hazmat.

[s/v 'Faith']

It is generally accepted that the first commercial production fiberglass sailboat was the Pearson Triton.

There have not been structural failures reported because of age. Some of the older fiberglass boats are laid up with a better (WRT longevity and blister resistance) then newer formulations.

It is significant to note that regular old poly/vinyl ester resin seem to resist UV break down better then epoxy. Of course the UV effects are negated by the paint or gelcoat, but I wonder about some of the newer epoxy based hulls over time (time will tell).

I believe there were some military destructive tests conducted of fiberglass barges that concluded there were no significant structural compormises with age.

IIRC, Gord has the references and I suspect he will appear in this thread soon.

[delmarrey]

I cut up a 1958 Dorset El Dorado here a while back and the FG was still in good shape. It's just the unlaying particle board was braking down. My vessel is a 1979 and has taken a beating, it's still holding together.

I think it'll be 100 years or more before we really find out how long the stuff will last structurally.

There were some bad resins in the early to mid 80's that developed blisters but a survey would find those.

[Marksman]

Maelstrom is a 1966 and was raced hard for the first 10 years of her life. The exterior is in need of refinishing, again, but the laminate on the inside looks new (except perhaps in the bilge). I did some remodeling of the engine beds for a repower and while cutting some of the old glass, it smelled just like fresh new polyester. I don't know if that is any indication or just a feel good thing but the bottom line is after 44 years my hull has every indication of "like new" integrity.

[S/V_Surya]

This question has been asked and answered before:

http://www.cruisersforum.com/forums/...-last-818.html

[thinwater]

Originally Posted by s/v 'Faith'

It is significant to note that regular old poly/vinyl ester resin seem to resist UV break down better then epoxy. Of course the UV effects are negated by the paint or gelcoat, but I wonder about some of the newer epoxy based hulls over time (time will tell).

I recently sold a 32-year old Stiletto catamaran; epoxy Kevlar honeycomb with very thin skins, and only 1200 pounds for 27 feet. Never even a stress crack, and I gave her stress! As long as the epoxy is kept covered with good paint (and I have seen Stilettos where the paint was neglected and the UV had significantly damaged the epoxy and exposed laminate) there is no known age limit at this time. I certainly beleve the hull could easily go 50 years or more. Epoxy hulls tend to be COMPLETELY immune to blistering. However, you MUST keep up the paint (every 10-15 years).

[rebel heart]

36 and going strong.

[GordMay]

Here’s several papers on the subject by Prof. Paul H. Miller, Naval Architecture and Ocean Engineering Department, United States Naval Academy:
➥ Prof Miller's Project Page

Including (tho' not barges):

Fatigue Prediction Verification of Fiberglass Hulls
➥ http://www.usna.edu/Users/naome/phmi...ss%20Hulls.pdf

Durability of Marine Composites
➥ http://www.usna.edu/Users/naome/phmi...lJ24report.pdf

Stiffness Reduction of Marine Composites
➥ usna

Jeff H posted “A Primer on Fiberglass Construction” (and other valuable contributions) way back in 2003.
➥ http://www.cruisersforum.com/forums/...ction-619.html

➥ http://www.cruisersforum.com/forums/...-span-859.html

Originally Posted by s/v 'Faith'

... I believe there were some military destructive tests conducted of fiberglass barges that concluded there were no significant structural compormises with age.
IIRC, Gord has the references and I suspect he will appear in this thread soon.