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#396934
Hey everyone,

I was doing the pre-season glider inspection today, and found that the nico sleeves on my lower side wires have some kind of black discoloration on them (under the plastic). I'm not sure if it was there last season, but I have never noticed this before. Unfortunately I'm not sure what material these nicos are made from – they're standard WW parts – or how corrosion would look on it.

Could someone please confirm that this is indeed corrosion? If so, I assume the wires would need immediate replacement. Too bad, otherwise they look brand new.

I would also like to know if I'm doing something wrong with storage for this to happen to 2-year-old wires, or if this is normal. The glider is stored in a garage in a rather rainy location a few miles from the ocean coast (we only fly 100+ miles away from the coast).

I've attached a few pics of different nicos with varying amounts of alleged corrosion, any advice is appreciated.
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User avatar
By magicpotato
#396937
A quick Google search suggests that it is corrosion. Another tell tale sign of corrosion is if the aluminum starts turning a greenish color.
User avatar
By raquo
#396938
I tried searching for images of corroded nicos but didn't find any. Regarding green corrosion, wouldn't that be copper, not aluminum? I thought aluminum has white corrosion...
By Comet
#396939
Could it be mold or mildew?

I refer you to the classic article in Hang Gliding magazine where a pilot conducted actual load tests to failure on various flying wires. One set of wires tested were from an ancient WW Harrier stored outdoors near the ocean that appeared thoroughly corroded. He expected them to "emit the sounds of Rice Crispies" (snap, crackle, pop) when loaded, but in fact they failed at the same load as brand new wires. As I recall, it was somewhere in the 800-lb range.
User avatar
By RobertKesselring
#396940
Have you sent these pics to WillsWing? They would be the experts who could give you the most authoritative answer.

That said, if you question them, why not replace them? A set of wires can't be that expensive. We do this for fun, and I can't imagine it would be that fun if you're worried about your equipment dropping you out of the sky.
#396941
Raquo,

I agree with Robert; you can't have much fun on a glider that has issues.

NICOpress sleeves are copper, thinly coated with silvery zinc. Copper corrosion would be greenish. What you are seeing there does resemble Galvanic Corrosion, but it seems to be only where the crimper has touched. (A dirty crimper? :lol: ) I would want to remove the heat-shrink covering from one cable, and wash the black areas with alcohol and a cloth (nothing more). If the silvery zinc coating is completely intact, and the black deposits just wash away, then the metal has not been damaged. Use magnification (a jeweler's loop would be good, there) and a strong light to inspect the zinc coating. If the black stuff is metal-hard and will not wash away easily, that would probably be Galvanic Corrosion. Seawater would be a likely cause there, but the glider would need to be getting very wet, and a lot more than just the NICO sleeves would show corrosion. To see the black deposits only on the NICOs is very odd. Your top cables should be showing the same black deposits, if the issue is corrosion. Now if the black deposits were on the steel cable itself, then I'd say the cables are trash. Are you landing on dry lake beds, or alkali deserts or salt flats?

Give one cable end a wash, and let us know what you see, then. Close-up pix would be good.

If you ordered bottom cables now, after only two years of service, that seems like a very safe option, in any case. Trust in your gear is essential to having fun. If you do get new cables, keep your old cables, tagged as patterns for your glider, so you can check that any newer cables are correct in length.
User avatar
By NMERider
#396944
Send the first photo to Mike Meier, VP of Wills Wing and president of the HGMA along with the facts and report back his response.

I can tell you right now that what you're seeing is spots on the tin coating due to the presence of condensation from salt air. It's NOT zinc plating. It's tin plated copper. http://www.nicopress.com/documents/data ... oducts.pdf

It's also harmless as my good friend and flying partner Comet has already pointed out. But don't take the words from a bunch of grumpy old middle-aged mouse-pad pilots when you can take the word of a dry-witted manufacturing expert. https://www.willswing.com/contact/
User avatar
By designbydave
#396949
If there is any doubt what-so-ever in your side wires just replace them.

From the Wills Wing Sport 2 manual section on maintenance (every 6 months,) page 41, #4:
Inspect all cables and suspension system components, and replace any suspension system
component that shows any wear, and any cable that shows any kinks, wear, damage,
corrosion, etc.


I added the emphasis. So, yeah, just replace them. Granted, it would be nice to know if the signs you are seeing are indeed signs of corrosion or not, if only for curiosity's sake. But yeah, replace those wires.



http://willswing.com/wp-content/uploads ... y_2009.pdf
User avatar
By KTMPilot
#396951
Risk management: What about galvanic corrosion on the inside of the Nicopress sleeve, between the stainless cable and the sleeve, that may not be visible?

[/quote]That said, if you question them, why not replace them? A set of wires can't be that expensive. We do this for fun, and I can't imagine it would be that fun if you're worried about your equipment dropping you out of the sky.[quote]

:ditto:
User avatar
By klh
#396955
A "nico" is copper with nickel plating.
In my _personal_ opinion based on looking at your photos that black stuff you see is just surface discoloration of the nickel plating. The strength of the nico is inside where the copper flowed around the steel strands when it was pressed on.

That said, annual replacement of your side wires is a really good idea.
By Comet
#396960
NMERider wrote:Do the side wire stomp test. It's in the manual.
That test has always bothered me. It seems abusive to wires and could actually precipitate a problem.
It's kinda like saying "smash your helmet against the ground before every flight to make sure it's impact-worthy."


.
User avatar
By drachenjoe
#396963
Hmm,
corrosion on the nicopress sleeves can never result in black or dark-grey particles... Good advice from RED and NMERider btw..

PS : got 2 oldtimers last summer ( Bautek Pamir ) , built 1993. Factory checked in 1998, flown til 2000. Still the original downtubes and wires. Bautek manual :" when you are sure that the wires are "unharmed", they must NOT be replaced after a certain time or flights...".
No kinks, no broken filaments, sleeves not deformed, pressed as it should be - I don´t worry, feel secure.
Scheisse happened only with wrong swageing or 1x19 "dental floss" side wires in aerobatics, as far as I know....
User avatar
By NMERider
#396967
Comet wrote:
NMERider wrote:Do the side wire stomp test. It's in the manual.
That test has always bothered me. It seems abusive to wires and could actually precipitate a problem.
It's kinda like saying "smash your helmet against the ground before every flight to make sure it's impact-worthy."


.
Dude, you crack me up. Never change. :thumbsup:
#396969
Campers,

Maybe these guys know what materials are used in their product.

http://www.nicopress.com/documents/data ... oducts.pdf

http://www.nicopress.com/products/detai ... ?type=Oval

:mrgreen:
User avatar
By Dave Jacob
#396972
Comet wrote:
NMERider wrote:Do the side wire stomp test. It's in the manual.
That test has always bothered me. It seems abusive to wires and could actually precipitate a problem.
It's kinda like saying "smash your helmet against the ground before every flight to make sure it's impact-worthy."


.

Structural materials move through an elastic zone prior to experiencing permanent deformation as the load is applied. As long as you stay in the elastic regime you will not be appreciably damaging your glider. So getting a decent estimate on the amount of force you are applying is important.
#396975
Dave Jacob wrote:
Comet wrote:
NMERider wrote:Do the side wire stomp test. It's in the manual.
That test has always bothered me. It seems abusive to wires and could actually precipitate a problem. It's kinda like saying "smash your helmet against the ground before every flight to make sure it's impact-worthy."
Structural materials move through an elastic zone prior to experiencing permanent deformation as the load is applied. As long as you stay in the elastic regime you will not be appreciably damaging your glider. So getting a decent estimate on the amount of force you are applying is important.
Dave,

You are correct, as far as the elastic zone is concerned, but I would have a hard time determining where that point might be, in the field. I stand with Comet on this one issue, and the problem here is stainless steel Work Hardening. Most stainless steel alloys are prone to Work Hardening.

Repeated heavy stresses will cause the cable to become more brittle (work hardened), which is why I go with visual inspections and scheduled replacements of cables. Under normal flying conditions, the stresses are not a problem, but rodeo air and frequent whacks ARE a problem. Adjust your replacement schedules accordingly. I do not agree with the Stomp Test; it may tell you that you should be safe today, but it may hasten the day when the cable fails, due to Work Hardening.

I have recently pulled flying wires to destruction that were over twenty years old (my own). They still pulled most of their rated strength, even that old. Breaking strength is not the problem. With the old cables, what did fall right out of the tree was the Shock Load capability. New cables could accept shock loads that broke the old cables in one try. This is the symptom of Work Hardening. You can not see it coming. Replace cables on a schedule, and that schedule needs adjustments to consider your flying in rodeo air, and landing whacks (both frequency and intensity). Noisy landings are not good for your cables, nor the rest of the glider, for that matter.

My $.02 worth.
#396976
red wrote:
Dave Jacob wrote:
Comet wrote:That test has always bothered me. It seems abusive to wires and could actually precipitate a problem. It's kinda like saying "smash your helmet against the ground before every flight to make sure it's impact-worthy."
Structural materials move through an elastic zone prior to experiencing permanent deformation as the load is applied. As long as you stay in the elastic regime you will not be appreciably damaging your glider. So getting a decent estimate on the amount of force you are applying is important.
Dave,

You are correct, as far as the elastic zone is concerned, but I would have a hard time determining where that point might be, in the field. I stand with Comet on this one issue, and the problem here is stainless steel Work Hardening. Most stainless steel alloys are prone to Work Hardening..
What did the folks at Wills Wing have to say about your concern of the issue of work hardening of stainless cable due to performing the side wire load test, red?