How's the Composites holding up?

Many moons ago, (early to mid-eighties), I was reading quite a bit of
material about the "new" composite airplane revolution and how different
life was going to be with the ability to make planes from the fantastic
substance. The main concern from the "experts" in many of these articles
was that they didn't know how the composite materials would hold up over
time. It seems that many folks thought that after years of sun exposure
and/or heat/freeze cycles, the materials might become brittle or degrade in
strength.

Now, obviously, I realize that there aren't many Long-EZ's falling out of
the sky and that many of the new methods are more advanced than the first
tries, but I was wondering how 25+ years has faired on these planes? Was
this fear just a crazy thought or was there some validity to the concern
that has reared its ugly head now that we've had some time to look back?

jf

"Jeff" jfranks1971 minus wrote in message
...
Many moons ago, (early to mid-eighties), I was reading quite a bit of
material about the "new" composite airplane revolution and how different
life was going to be with the ability to make planes from the fantastic
substance. The main concern from the "experts" in many of these articles
was that they didn't know how the composite materials would hold up over
time. It seems that many folks thought that after years of sun exposure
and/or heat/freeze cycles, the materials might become brittle or degrade
in strength.

Now, obviously, I realize that there aren't many Long-EZ's falling out of
the sky and that many of the new methods are more advanced than the first
tries, but I was wondering how 25+ years has faired on these planes? Was
this fear just a crazy thought or was there some validity to the concern
that has reared its ugly head now that we've had some time to look back?


You can get $20,000 for a glass glider built in the '70's.

Does that answer your question?

http://www.wingsandwheels.com/wantads1.htm

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

"Capt. Geoffrey Thorpe" The Sea Hawk at wow way d0t com wrote in message
news:AvWdnQSRlpgvFUPZnZ2dnUVZ_sWdnZ2d@wideopenwest .com...
"Jeff" jfranks1971 minus wrote in message
...
Many moons ago, (early to mid-eighties), I was reading quite a bit of
material about the "new" composite airplane revolution and how different
life was going to be with the ability to make planes from the fantastic
substance. The main concern from the "experts" in many of these articles
was that they didn't know how the composite materials would hold up over
time. It seems that many folks thought that after years of sun exposure
and/or heat/freeze cycles, the materials might become brittle or degrade
in strength.

Now, obviously, I realize that there aren't many Long-EZ's falling out of
the sky and that many of the new methods are more advanced than the first
tries, but I was wondering how 25+ years has faired on these planes?
Was this fear just a crazy thought or was there some validity to the
concern that has reared its ugly head now that we've had some time to
look back?


You can get $20,000 for a glass glider built in the '70's.

Does that answer your question?

http://www.wingsandwheels.com/wantads1.htm

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.


Yes, it now appears that composite gliders will outlast metal ones. The
gelcoat will degrade but the underlying structure seems to last forever.

"BobR" wrote in message
oups.com...
I would say that the ongoing, expanded use of composites in both the
experimental aircraft field along with production aircraft should
answer any questions. The use of composites in the large commercial
aircraft is increasing an a much faster rate than in the small plane
market although the Cirrus might prove an exception to that fact.



I didn't mean to sound as if I was saying there was anything wrong. I
assumed that newer "versions" of composites and processes had made it much
better and safer. I just wondered if the original composite planes ever
experienced any of the "doom" problems over time....it would appear not

jf

"Capt. Geoffrey Thorpe" The Sea Hawk at wow way d0t com wrote in message
news:AvWdnQSRlpgvFUPZnZ2dnUVZ_sWdnZ2d@wideopenwest .com...


You can get $20,000 for a glass glider built in the '70's.

Does that answer your question?


Honestly, no.

If you go to a gliderport, you won't see many gliders tied out in full
sunlight as is common with airplanes. Usually they are disassembled and stashed
away in covered trailers specifically to protect their expensive finish from the
degrading effects of the sun. That said, if you find an old G109 motorglider
tied out at an airport, (it looks like an airplane with long wings) you are
possibly looking at a composite aircraft that has actually survived decades in
full sunlight, and done so quite well.

Vaughn

Yes, it now appears that composite gliders will outlast metal ones. The
gelcoat will degrade but the underlying structure seems to last forever.


be careful, guys; you have to distinguish:

one thing is the gelcoat. it protects the fiberglass (or carbon) structure
underneath from UV light which harms the epoxy resin. regular gelcoat is
not resistant to UV light forever; cracks in the gelcoat work their way
into the laminate. a while ago, i had to repair the outer layer of glass of
a fiberglass wing just because of that. the problem appears especially when
the gelcoat (or filler, when using automotive paint) is very thick, making
the surface or paint layer too stiff to follow the fiberglass' strains,
which results in cracks.

another thing is the structure itself. as mentioned above, it's strength can
be affected e.g. by UV light and it has to be protected against. if this
protection is maintained, and the structure had been designed and
calculated in a correct way, fatigue is not really an issue, and the
material's strength remains. aluminum is much worse...


uli

"Vaughn Simon" wrote in message
...

Honestly, no.

If you go to a gliderport, you won't see many gliders tied out in full
sunlight as is common with airplanes. Usually they are disassembled and
stashed away in covered trailers specifically to protect their expensive
finish from the degrading effects of the sun. That said, if you find an
old G109 motorglider tied out at an airport, (it looks like an airplane
with long wings) you are possibly looking at a composite aircraft that has
actually survived decades in full sunlight, and done so quite well.

Vaughn

I think you are missing the simple stuff.......
If you go to an Airport, you won't see many composite airplanes tied out in
the open.
They are almost universally hangared, which I might add is a better climate
than a trailer
in the sun, on the line at Minden, Cal City or any of the other great
soaring spots.
I believe 30 year old sailplanes in trailers are directly comparable to
hangared composite
aircraft, and the use of a hangar is BETTER for the airframe than a trailer
in regards to control
of temperatures inside the box. Early composite sailplanes remain airworthy
despite the use
of rolling ovens, a risk composite airplanes are not subjected too.

Scott.

"Vaughn Simon" wrote in message
...

"Capt. Geoffrey Thorpe" The Sea Hawk at wow way d0t com wrote in message
news:AvWdnQSRlpgvFUPZnZ2dnUVZ_sWdnZ2d@wideopenwest .com...


You can get $20,000 for a glass glider built in the '70's.

Does that answer your question?


Honestly, no.

If you go to a gliderport, you won't see many gliders tied out in full
sunlight as is common with airplanes. Usually they are disassembled and
stashed away in covered trailers specifically to protect their expensive
finish from the degrading effects of the sun. That said, if you find an
old G109 motorglider tied out at an airport, (it looks like an airplane
with long wings) you are possibly looking at a composite aircraft that has
actually survived decades in full sunlight, and done so quite well.

Vaughn

So much for the quick and easy smart ass version of the answer...

On the other hand, if you go down to your local boat yard, you should not
have any trouble finding fiberglass stuctures that have been outside in the
sun and weather since the 1960's and are holding up just fine. Some of them
will look like doo-doo because, well, gel coat just doesn't hold up over
years of exposure without regular buffing and waxing. Having owned 30 year
old fiberglass boats, I have:

A) Learned to hate fiberglass (it itches).
B) Learned that the basic laminate holds up just fine.
C) Learned that wood cores, secondary joints and gel coat is where you find
problems. They can be repaired, but refer back to lesson A).

Going back to the original post in this thread:

The main concern from the "experts" in many of these articles
was that they didn't know how the composite materials would hold up over
time. It seems that many folks thought that after years of sun exposure
and/or heat/freeze cycles, the materials might become brittle or degrade
in strength.

I would argue that composite structures, like just about any other, seem to
be holding up OK, but they have their advantages and their disadvantages.
Gel coat sucks, but even paint needs to be re-done every once and a while,
eh? Keep it out of the sun, and the finish lasts a lot longer in either
case. Fatigue is an issue with both composit and aluminium strucures,
Corrosion is a problem with aluminuim, secondary bonds can be a problem
with composites.

If you keep up with the maintaince you are a lot better off than if you let
it go and try to "restore" a P.O.S. (Airplanes or boats, no matter what the
primary structual material is.)

Personally, I like wood.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

"Jeff" jfranks1971 minus wrote in message
...

"BobR" wrote in message
oups.com...
I would say that the ongoing, expanded use of composites in both the
experimental aircraft field along with production aircraft should
answer any questions. The use of composites in the large commercial
aircraft is increasing an a much faster rate than in the small plane
market although the Cirrus might prove an exception to that fact.



I didn't mean to sound as if I was saying there was anything wrong. I
assumed that newer "versions" of composites and processes had made it much
better and safer. I just wondered if the original composite planes ever
experienced any of the "doom" problems over time....it would appear not

jf
One example is the Glasflugel Libelle first-generation composite sailplane
first sold in the mid 1960's. Most of them are still flying and in
beautiful condition to boot. They sell on the used market for 10,000 to
15,000 Dollars.

A few of the early composite gliders used balsa core sandwich construction.
If the core got wet and fungal rot started, the structure is toast.
Construction techniques switched to closed cell foam core early on so these
are rare.

I understand some current glider construction techniques eliminate the
sandwich and go with solid pre-preg carbon skins. It's posible to eliminate
the spars too and build a wing that is simply a hollow airfoil shaped tube.

Bill Daniels

In article ,
"Bill Daniels" bildan@comcast-dot-net wrote:

One example is the Glasflugel Libelle first-generation composite sailplane
first sold in the mid 1960's. Most of them are still flying and in
beautiful condition to boot. They sell on the used market for 10,000 to
15,000 Dollars.



Yep, I own H301 Libelle #19. She's 42 this year. Flew 5 or 6 flights of
200 miles long or more this past spring. About 2500 hours flying time.
I've put about 300 on her in the 5 years I've owned her. Flown through
some hellacious turbulence and some pretty hard cowpasture landings.
She's still smooth and shiny although some small areas of finish are
starting to turn a bit yellow. No structural problems. No AD's on the
composite structure.

The more modern composite birds like the Diamond DA-20 hold up pretty
well even sitting out in the weather for years.