Today's Message Index:
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1. 07:40 PM - Errata on tighting wing/fuse hardware (mppalmer@aol.com)
2. 08:29 PM - Re: Errata on tighting wing/fuse hardware (Craymondw@aol.com)
Message 1
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| Subject: | Errata on tighting wing/fuse hardware |
I guess I wasn't clear. This was the second time I've re-torqued the
hardware in the life of the plane.
But you're correct - twice in 17 years isn't bad.
The nuts are marked with nail polish. It's not a matter of the nuts
backing out. It's a matter of the fiberglass changing dimension.
It could be the high density foam crushing over time in addition to the
resin shrinking.
Yes, I can believe that the resin is constantly shrinking/curing.
Someone told me once that, with the Glasairs, this is because the resin
was never oven cured and so is constantly shrinking as it (still)
cures. Remember how the factory started to oven cure the fiberglass
gear legs on the FT's and TD's after a while? Taking them to a certain
temperature in the oven made thema a lot stronger. Before they were
oven cured, they used to creep outward.
I know that here, in sunny, hot Phoenix, the dark red fairings on our
Glasair have shrunk. You can see the texture of the weave of the cloth
over time - kinda like the bones poking out in an emaciated person.
And, consistent with oven curing, the engine mount to fuse bolts only
needed to be re-torqued once. The heat of the engine compartment seems
to have done a final cure and any further shrinkage there has been
minimal.
In any event, next time you're doing maintenance on the airplane, check
for things like this. We tend to think the static parts stay static.
But no harm in putting a wrench on them to make sure.
Report your results here. It should be interesting to know what the
rest of you find with attach hardware tightness on your plane.
Mike <><
Message 2
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| Subject: | Re: Errata on tighting wing/fuse hardware |
Fiber glass pioneers like you will provide the data for future designs and
maintenance and your knowledge will be incorporated into manuals. That
German friend of mine informed me that the first German made fiber glass
glider manufactured back in the late 1950's still flies!! 1950's resins, glass
cloth and building techniques have evolved since then and there is no co
mparison with today's products and technology. My German friend thinks over
built Glasairs will be the D.C.3's of the future. After 21 years my fuselage
skins are beginning to pull in a tiny bit and what was once a perfectly
faired surface is beginning to look a little puckered in spots. From new, when
I hangered my plane, I use a jack with a one foot by one foot board with a
cushion of hard rubber foam and jack my wing up until the wheel comes off
the ground, then I let the jack down completely and then jack it up about
and inch or so to take the weight off the landing gear so that it doesn't
splay out. Before I flew a Glasair I flew Grumman Tigers that had fiberglass
legs and noticed the landing gear splayed out after a while and hoped to
avoid that. I too mark all bolts and nuts with a line of red paint. When I
saw that on my over hauled engine I thought it was a good idea.
Too bad you are dropping out, I always took your advice.
Chuck Raymond
N16CD Gl2SFT 200HP
In a message dated 6/5/2012 10:47:44 P.M. Eastern Daylight Time,
mppalmer@aol.com writes:
--> Glasair-List message posted by: mppalmer@aol.com
I guess I wasn't clear. This was the second time I've re-torqued the
hardware in the life of the plane.
But you're correct - twice in 17 years isn't bad.
The nuts are marked with nail polish. It's not a matter of the nuts
backing out. It's a matter of the fiberglass changing dimension.
It could be the high density foam crushing over time in addition to the
resin shrinking.
Yes, I can believe that the resin is constantly shrinking/curing.
Someone told me once that, with the Glasairs, this is because the resin
was never oven cured and so is constantly shrinking as it (still)
cures. Remember how the factory started to oven cure the fiberglass
gear legs on the FT's and TD's after a while? Taking them to a certain
temperature in the oven made thema a lot stronger. Before they were
oven cured, they used to creep outward.
I know that here, in sunny, hot Phoenix, the dark red fairings on our
Glasair have shrunk. You can see the texture of the weave of the cloth
over time - kinda like the bones poking out in an emaciated person.
And, consistent with oven curing, the engine mount to fuse bolts only
needed to be re-torqued once. The heat of the engine compartment seems
to have done a final cure and any further shrinkage there has been
minimal.
In any event, next time you're doing maintenance on the airplane, check
for things like this. We tend to think the static parts stay static.
But no harm in putting a wrench on them to make sure.
Report your results here. It should be interesting to know what the
rest of you find with attach hardware tightness on your plane.
Mike <><
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