Fibreglass and ageing

[Guest]

Hi,

I am writing from Sydney, and I am in the process of buying my first yacht. I will have to buy an older boat. ( I am looking for a fibreglass one) The age of the boats that I am looking at are from the early 80's. I am just wondering if there is an age limit on fibreglass. When is a fibreglass boat too old?!

 

[RobertMartin]

I own a Swarbrick S111 ( australian ) from 86, the hull is in great condition, just check it has not got blisters ( if it has not, it never will, not if its 20 yrs old ). I have never heard of a well built fiberglass yacht being put out to pasture... There are still boats from the 70's sailing in Sydney Harbour.... I think you should be more worried about the age of the rig.....

Bobby aka Seawolf..
Sail as if your free

 

[Guest]

My dad has a fibreglass boat that was built in the late 60's or early 70's (I can't remember exactly when). It was built like the proverbial brick small room by a backyard builder and shows absolutely no signs of delapidation at all. It depends on whether it has been looked after ie regularly anti-fouled and maintained as well as how well it was built to begin with.

I tend to agree that the motor, rig and sails are also expensive to repair/replace so should be checked out as well as the hull.There's a lot more dead wooden boats at 20 years than fibreglass, primarily due to the higher maintenance rate of wooden boats required and a lack of enthusiasm on behalf of the owners to do the maintenance. Epoxy systems are making wooden boats easier to live with but it wasn't in common use back then.

 

[trev]

A little osmosis never hurt anyone !! I had a boat built in '71 which was showing some signs of blistering when I bought her in '84. Kept the boat for seven years, no sign of anything critical, then sold her via brokerage.
Saw her in the Medway a couple of years ago - still going strong !

Trev

 

[gary_yank]

I have a 1974 fiberglass boat with no blisters or other similar problems. I would be more worried about the rig, as others have stated, and the keel bolts. With good care fiberglass boats should last a very long time.
From the other coast of the US,
Gary

 

[Guest]

I have a GRP boat built in 1965 and she has never shown any signs of problems with the lay-up. They built them well in those days.

I have just purchased another built in 1975 and again, no problems.

In recent years builders have moved away from the old "belt and braces" way so it will be interesting to see how boats built in the late 80's and 90's hold up to 35 years of use.

Just get the moisture content checked out and if it is OK, you cant go wrong. Another thing to look for is areas of spongy glass. This usually means that the sandwich layer has broken down (usually a light wood like balsa), possibly due to it getting wet and rotting.

Spend a couple of $ on a survey as that "should" pick up any of these issues.

Regards

 

[bedouin]

No one knows - I have heard experts estimate the life of fibreglass as being 200-300 years but at present there is no empirical evidence for that.

Bedouin is just about to celebrate her 30th birthday, and is as strong as the day she was built. Paradoxically I would worry more about boats built in the late 70s and 80s.

Because it was a relatively knew process, most of the earlier fibreglass boats are very heavily made by modern standards.

 

[Footpad]

Re: Plastic Gribble?

Whats anti-fouling got to do with the life of fibreglass? You're not trying to start those old "plastic gribble" rumours again are you?

 

[billmacfarlane]

I don't think anyone knows. Do you mean the actual fibreglass itself or the gelcoat that covers it ? The first fibreglass( GRP) boats had a comparatively heavy lay up , by that I mean the thickness of the fibreglass layers was greater than modern grp boats. Thats only part of the story as a hulls "strength" is dependent on more than that e.g the stringers that are bonded to the hull to support it and stiffen it. Whether a heavily laid up older boat is more impact resistant than a lighter lay up reinforced with Kevlar is open to debate , and I'm sure it will be. I haven't heard of a boat that has had to be scrapped through "ageing" . For my own part my first GRP boat built in 1965 is still sailing , but I had to get full osmosis treatment done and also crumbly gel goat removed from the topsides due to very bad lay up - in 1965 the process was less well understood than now. Do bear in mind that if you buy an older boat everything in the boat is the same age , sails , possibly rigging , woodwork , wiring and engine and some of these might need some attention and money spent.

 

[billmacfarlane]

Wasn\'t that the polyesthermite ? NM

!

 

[jamesjermain]

GRP hulls will keep on going, as previous posters have said and a 1980s boat is hardly getting into her stride. I had a 1972 Pioneer 10 which had been built (by a previous owner) to cross the Atlantic and reinforced for the puspose. For various reasons she did not go. She served us well for seven years in the 1990s with passages to Ireland, France and elsewhere. I have just heard from her new owners that they are re-rigging her, refurbishing the interior and taking part in next year's Atlantic Rally for Cruisers (ARC) so she will, 30 years after her berth, be achieving that for whcih she was intended.

As others have indicated, It is often the interior, rig, sails and engines of older boats, which give out first. Many people are now buying older, poorly maintained GRP boats (1970s classics like Nich 32s, Rivals, Contessas etc are popular) for comparatively little money,then spending £5,000 to £10,000 on refurbishment. The result is a boat in good-as-new condition for considerably less than even a discounted Jenbenbav.

JJ

 

[david_e]

A question James; if technology advances as Bill comments, why spend this money on a much older boat, with the higher running costs, when you can have all the benefits of a new one. The differences over a long period can't be that great? Bearing in mind the advantages of the exchange rate at present, and also the fact that 10-15 year old ben/jens fetch remarkably good money now? Do you have concerns about the build of new ben/jens?

PS, didn't get time to formally say hello, but we were the couple who bought the subscription last thing on Saturday, when your asst did the dodgy thing with the card!

 

[Guest]

Re: Plastic Gribble?

NO, but I guess the point I was trying to make is that any boat that is being looked after is more likely to be OK than one that isn't. The boat with two foot long weed and barnicles that appear like the surface of the moon generally indicate neglect.

Mind you a boat like that should be real cheap and probably worth looking at in the light of fixing it up.

 

[davidhand]

Re: Plastic Gribble?

I once looked at older boats, saw some in almost pristine condition, and some neglected. When I sat down and did some figuring in every case I would have been better off paying the higher price for the one in a good state of repair, as I could not have brought the beaten up one up to par for the price differential.

 

[jamesjermain]

Good point

One hopes that having spent all that money on an older boat maintenance costs will be similar to those of a new boat.
There is still a saving in capital cost by doing a rebuild but I admit that, with the prices of some new boats being what they are, the margin is not as great as it might have been a few years ago.
I think there is a difference between asking and getting. Many owners of two or three year old models of the marques currently so cheap, are finding that the value they had hoped to put on their boat, secondhand is actually higher that the price of a new boat of the same size. They are having to revise their figures accordingly.
Some people, of course, and often for good reason, prefer older models for their looks, handling and interior design.

JJ

 

[Stemar]

I'm not an engineer, so take this with a pinch of caution, but from what I've read, fibreglass (GRP) is slightly porous, so eventually, it will become saturated with water if it stays in the 'oggin. Whether that matters depends on the quality of layup. A poor layup with voids, and too much leftover styrene from the curing process will cause blistering. If it's really bad, it can cause structural failure, but that's very rare. Most boats, treated or not, won't lose a significant amount of strength from this.

The other weakness of GRP, in all its various flavours, is fatigue resistance. Wood and metal, if not stressed (flexed) over a certain limit will never develop fatigue, but GRP will, eventually. The more it's flexed, the quicker this will happen. Some of the old "brick privvies" from the 60s & 70s, and a few later boats are so stiff that it could take centuries, but more recent featherweight flyers and marina hoppers flex significantly in a blow. As a result, I'd be leary of them a few years down the line especially if they've been used hard.

Unfortunately, I don't know enough to be sure how this fatigue would show up, but I suspect it would be progressive, rather than catastrophic, at least under normal conditions, with less and less resistance to flexing. I have sen one old boat of very light construction where the gelcoat has crazed in several areas of the hull. I suspect that this may be due, at least in part, to the onset of fatigue in the layup. Definitely one to walk away from, other than as a real cheapie for light day sailing.

Personally, I'd far rather have a good old'un than a mediocre new one, even if the old'n's slower!

 

[vyv_cox]

Fatigue in Fibreglass

Some inaccuracies in this posting.

Fatigue results from the cyclic application of stress. All materials have a fatigue limit expressed as a stress, below which fatigue will not occur, except in special conditions. Fibrous materials like wood, GRP, cloth, have good fatigue resistance provided that the stress is applied in the optimum direction, which is the art of the good designer in these materials.

Generally composites show excellent fatigue resistance when compared with most metals. However, since fatigue failure tends to result from the gradual accumulation of small amounts of damage, the fatigue behaviour of any composite will be influenced by the toughness of the resin, its resistance to microcracking, and the quantity of voids and other defects which occur during manufacture. As a result, epoxy-based laminates tend to show very good fatigue resistance when compared with both polyester and vinylester, this being one of the main reasons for their use in aircraft structures. One of the main criteria in fatigue life is adhesion of the glass fibre to the resin and most composite research concentrates upon this. This is possibly the reason that epoxy composites are better in fatigue than polyester. However, even the poorest quality layup will achieve a reasonable degree of bonding.

I have some doubts that crazing of gel coat is a form of fatigue, more like a brittle fracture due to very low ductility, and crazing does not mean that the fundamental structure is affected. Leisure boat hulls see remarkably few stress cycles in their lives and fatigue is unlikely to be a significant factor.

 

[Guest]

you haven\'t met the polyesthermite? ye**!\"$$**

how long have you had a GRP boat? Don't tell me you haven't had her bottom teacake clad?

-{)>

 

[oldharry]

How much longer...?

My little old 'Portly', (the boat - not me, tho certain members of my SC profess confusion!) Celebrated her 40th year this last season, and according to the latest survey appears as sound as the day she was launched: OK new keelbolts etc at various stages in her life, and we celebrated her anniversary with a new set of standing and running rigging - but they are 'consumables' anyway.

Of course being very early GRP, she was built to timber scantlings, and is solid as a tank (sails like one too, some say...) - certainly never any problem of flexing anywhere with her (also rather portly) owner jumping around the decks.

Mind you a 19.5 footer that weighs in at over 2 tons displacement needs to be fairly solid......

Quite happy at the thought that my great great x5 grandchildren might still be enjoying her around stardate 2250, and judging from her current condition this would not seem entirely wishful thinking.

 

[Guest]

More stress out of the water ?

I think it would be fair to say that boats are designed on the basis of them being in the water. The 'push' of buoyancy being a good thing and even when the rough stuff comes, at least the boat will 'give' and ride to the pressure of sea and wind from the sails.

I have often read that severe distortion often occurs due to chocks not being placed over bulkheads and very few cradles pads also not being in the right place. If you look closely at boats they also are taking the weight mostly on one side or the other. If you then add the fact that many of us tend to leave the mast up to save a few bob even a moderate blow will add severe loads to these weak areas. The odd times that we have to run under bare poles highlights the power that's going on in the mast.You can often see the stress areas shown in the antifoul particularly when owners antifouled many months before going in. I often wonder if this is the reason why some yachts seem to perform better on one tack than the other. All this is of course compounded on newer yachts that have a far thinner lay up than say 1970's boats.

It does seem rare though for GRP boats to sink from fatigue/stress. There appears far more likelyhood that our masts will fall down due to poor/old rigging materials and holing of the boat. The most worrying thing I saw at Southampton lost year on about 6 different new boats was how poor the rigging plates were.