Jump to content

Rust spots on fly wires


sandman

Recommended Posts

Replacement!!!

 

I used a Maricat for years with rusty stay wires, all went well until the day it didn't. they just snap when they go with no warning. We dismasted, rolled the sail around the boom, lashed the mast and boom to the trampoline and started paddling back to the beach.

 

Or you could wear a parachute.

 

 

Link to comment
Share on other sites

Safety-critical steel wire rope of any type, must be replaced when damage, wear or corrosion reaches 10% of the thickness of the wire. It is easy enough for corrosion pitting to reduce wire thickness by 10% or more.

 

 

Link to comment
Share on other sites

Most

 

Just wanting to know what people are using to get rid of rust spots on the flying wires, cheers.

In my experience it may be bug guts not rust. Get a blue scour pad and wd40 and try gently cleaning the marks off.

 

Kiwi

 

 

  • Agree 1
Link to comment
Share on other sites

If the wires are SS 316 grade or higher you are more likely to get what is known as tea staining which is not a problem initially but it can develop in to rust if not cleaned. There are all sorts of corrosive elements (salts, acids etc) in the atmosphere and when combined with water, corrosion begins. It normally happens at connection points like thimbles and turnbuckles etc. A regular cleaning regime will keep wires and attached hardware in good condition. If it is bugs given the description of "Rust Spots" a good thorough clean with warm water & mild detergent should dislodge the goo. When I sold my last (old) hang glider the SS wires were still in pristine condition even though much of the soaring was done along coastal ridges with plenty of salt spray because I always washed the wires after a weekend flying.

 

 

Link to comment
Share on other sites

A while back two guys from down south ( names withheld ) flying to the top of cape york, in their Drifter, landed on my strip to take a break as the weather was turning nasty! one guy was flying solo and the other had his young son and a lot of gear on board...As I always do I went down to the strip to say G`Day and as I walked around the AC of the guy with his son on board, I looked at the wires and saw what I suspected was rust, so I said to the guy, "Do you realise that`s rust on those wires" he replied, "No that`s red dirt", again, I said it was rust and he came back with the same answer.

 

A friend of mine, also a Drifter owner/pilot who was there with me at the time, overheard what I`d said, took hold of the wire, gave it a bit of a pull and the wire snapped, he pulled on another wire and it snapped, the owner of the Drifter couldn`t believe what had just happened and couldn`t stop thanking me, for possibly saving his and his son`s life.

 

Both of these guys intending to fly to the top end were experienced pilots, one was a respected member of this Forum, yet, neither had noticed what turned out to be rust, it also turned out that the guy had fitted new wires just two years ago.

 

I lent the guy my car and sent him to Cairns to buy new good quality wire and swages then using my swaging tool we made up all new wing wires... The guy didn`t want to do the tail wires but I convinced him on why he should so we did and then I test flew it for him... The weather never improved and by this time, both Drifter pilots were more than grateful just to be able to fly back to where they`d come from.

 

Moral of the story. If you`re not sure of the safety of the wires or any other part of the aircraft, get advice from someone who does know... Fortunately! this story does have a happy ending.

 

Franco (Frank)

 

 

  • Like 4
  • Agree 1
  • Winner 2
Link to comment
Share on other sites

The guy didn`t want to do the tail wires but I convinced him on why he should ...

It never ceases to amaze me, the number of people who will hesitate to replace components, or spend money on repairs, to something that their life depends on!
  • Like 1
  • Agree 2
Link to comment
Share on other sites

It never ceases to amaze me, the number of people who will hesitate to replace components, or spend money on repairs, to something that their life depends on!

I still remember my exact words to the guy, which were, " If you don`t have enough respect for your own life, think about your son`s life", brutal I know, but it worked!

Franco.

 

 

  • Like 4
Link to comment
Share on other sites

I think there is a big difference between a rusty stain and a rust pit. Also, as any sailor knows, it is the unseen rust inside the wires that are the stress raisers that result in instant failures. Sailboats have been losing masts to this ever since stainless steel started being used the hold masts up. Aviators should know by now.

 

Well done Frank

 

 

  • Like 1
  • Agree 1
Link to comment
Share on other sites

The problem is, there's stainless steel, and there's stainless steel - and then there's Chinese stainless steel.

 

316 should be in standard use where corrosion is a potentially lethal problem - but it's often replaced by a stainless steel of lower corrosion resistance, such as 304.

 

304 stainless is simply a "general purpose" stainless steel, mostly used for commercial food production areas, and kitchens and household goods.

 

304 contains 18% Chromium and 8% Nickel - with no other added alloying elements. 304 is also often called "18/8 stainless" (the number referring to the Chromium and Nickel percentages).

 

316 is specifically designed for salty conditions. 316 contains 16% Chromium, 10% Nickel, and a minimum of 2% Molybdenum. The Molybdenum is added to help resist corrosion to chlorides (such as contained in sea water).

 

Chlorides are also dispersed from many other areas, such as industrial by-products, and many rocks and soil types - as well as coming from other types of naturally-occurring salts, such as Magnesium and Calcium salts.

 

Corrosion in stainless steel is normally caused by damage to the naturally-occurring "passivation layer" on stainless steels, or by undesirable inclusions in the stainless steel, such as Carbon steel, or chunks of foreign material such as ceramics from furnace linings.

 

Good quality stainless steels are pickled and passivated chemically, post-production, to provide a blemish-free passivated surface, that provides top-class corrosion resistance.

 

 

  • Agree 1
  • Informative 1
Link to comment
Share on other sites

Its not just the wire cables either ;). I had to swage up all new strutt,tail and control wires on my old jackaroo. The wires appeared new and the swages wrapped in a heat shrink? I removed the heat shrink to inspect the swages and they were green,corroded/calcified heavely and a couple had been over crimped and split !!!!!!! 2 and 3mm stainless 316 cable and swages fir the whole thing was under $200. On the strutt cables i went with a double swage (like my old N11) didnt cost more than $10 extra for the extra swage that wasnt needed but i felt better having them.

 

 

Link to comment
Share on other sites

The average person believes that Stainless steel does not corrode. I owned a balustrading business and used a lot of SS in balustrading, gates and pool fencing. When frameless glass became popular and anodised or powder coated aluminium gave way to stainless steel for the spigots, I would tell customers to keep the spigots & glass clean especially around salt water pools. Of course many ignored my advice and came back complaining of the staining and corrosion even after I'd told them that stainless steel will tea stain and rust, it just stains less than other steels. The glass also suffered as it eventually etched. After a while I wrote up a maintenance procedure and had them sign it when accepting the quote. The best spigot manufacturers used a higher grade than 316. 2204 was one of these I think.

 

 

  • Like 1
Link to comment
Share on other sites

Few people realise how corrosive most salts are.. Some stainless is more subject to fatigue also. It's telling that the cables were only 2 years old.

 

Franco Airlines.... the 5 star outfit in the North. Nev

 

 

  • Like 2
Link to comment
Share on other sites

I`ve been flying my Drifter in a high salt air environment since 1988. I`m on my second set of wire cables that I made up, using 316 stainless, at the last refurbishment, which was 10 years ago.

 

When I first started noticing tea staining on the original cables I decided to keep all the cables and swages lubricated. I tried gear oil, then grease and I applied it by putting it on a cloth and sliding the cloth along the cables, this would also pick up any broken strands if there were any, it was a bit messy but it did stop the tea staining. I`ve always kept my second set of cables and swages lubricated and recently I decided to try Diesel, to date there`s been no signs of tea stain, rust or any ill effect from these products.

 

Something else to be aware of is the effect of a Hornet`s (mud wasp) nest. For those who don`t know! It`s made up of mud which the Hornet uses to attach to some object and it has an incredible corrosive effect when attached to a metal, especially aluminium...A guy who flew from here and kept his Kit Fox in the shed here found a large Hornet`s nest built on one of the rudder cables, in an area that was not noticeable on a normal preflight inspection. The mud had corroded the cable right through to just a couple of strands which could have snapped at a most critical moment.

 

Franco.

 

 

  • Like 1
  • Informative 1
Link to comment
Share on other sites

Thanks, Guys, you`ve given me a bit of a chuckle! 006_laugh.gif.0f7b82c13a0ec29502c5fb56c616f069.gif....002_wave.gif.62d5c7a07e46b2ae47f4cd2e61a0c301.gif.

No worries franco you keep on proving it . I'd be a bit careful with the diesel though, the sulphur in it will bite into even 316. maybe RP7 or our own invention , WD40 soaked into the cloth .

 

 

Link to comment
Share on other sites

Yeh. Diesel isn't good. Some of the spray can preserving waxes might be a lot better. Use on new machined parts like ground crankshafts. ballraces, gears etc Wipe off the excess Wash out with Genthin thinners on a very damp rag, and renew occasionally. Nev

 

 

Link to comment
Share on other sites

There are Galvanised and SS wires, The gal wires get rusty and will break before the SS usually, but it is easier to check their condition. SS wires may look good, but if when running a cloth along them you find a broken wire, it is time to replace them. One strand of Gal wire broken is nowhere near such a big deal as a strand of SS.

 

Thrusters comment about rust in tractor tanks reminds me of one big No No. Never make a diesel tank with galvanised steel. I really don't know why, maybe the diesel attacks the gal, or maybe the gal is a problem with the fuel injection equipment. Maybe using diesel to wipe gal wires could be a problem. Who knows?

 

 

Link to comment
Share on other sites

I`ve tried various products to stop surface corrosion on the Rotax engines I`ve had, all of them left the engines oily, dust stuck to them and eventually, I`d have a hell of a job cleaning them up... For about 6 months, I`ve been regularly lightly applying Diesel with a paintbrush over the whole 503 DCDI I`m currently running and at this stage, I`m very pleased with the result and will continue doing what I`m doing.

 

 

Link to comment
Share on other sites

Years ago I bought a lot of old Indian NOS parts, They had been stored immersed in diesel, The majority of them were useless. An even coat of quite thick rust was on all of them and since they were precision items I did my money. WD 40 smells like it has some in it.. Nev

 

 

Link to comment
Share on other sites

It's likely that we have better quality diesel than we used to. I've not had the primary fuel filter clogging that I used to in the tractor I use for mowing.. It was a bacterial growth that completely blocked a gauze screen that wasn't at all a fine mesh. probably in conjunction with moisture collecting in the lower parts of the tank... Nev

 

 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...