standing rigging and swage terminals

Discussion in 'Sailboats' started by urisvan, Jan 6, 2011.

  1. urisvan
    Joined: Nov 2005
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    urisvan Senior Member

    i have a question about standing rigging and swage terminals. I don't know the age of my rigging but more than 10 years old.
    Anyway when looking closely there is no cracks on the swage terminals, the liftins are ok, but the section of the wire where it is entering through the swage terminals looks brown. I don't want a sudden breakdown on the sea.
    some says that, first there should be cracks on the swage terminals because of the expansion of the corroded wire inside the swage terminal. but some says that there can be sudden failure from there.
    what do you know and think about it?

    regards
    ulas risvanoglu
     
  2. gonzo
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    gonzo Senior Member

    Without knowing the alloy of the wire and the swages it is difficult to say
     
  3. Landlubber
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    Landlubber Senior Member

    ulas,

    Commercially, 10 y.o. rigging is past its due date. Insurance companies will not touch it.

    Galvanised wire could be still quite OK if it has been looked after, but ss would definately be suspect.
    ss wire will spring one strand (usually), if that has occurred, it is scrap.
     
  4. michael pierzga
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    michael pierzga Senior Member

    Cracks and as a result rigging problems , can be hard to see. Rust is the first indicator of problems. Always investigate closely a rust stained fitting.

    " Swaging " cold presses the tubular terminal fitting with a press to deform the metal and create a friction bond to grip the wire. The compressed metal now has internal stress permananly pressed into it and is subject to stress corrosion . Lower rigging terminals...the ones that " look Up" are most prone to water intrusion and thus stress corrosion , cracking, failure

    Its very hard to tell if the swage fitting is good or bad. Rust stains may or may not indicated problems.

    Clean well with a scotchbrite pad and autumotive brake cleaner spray , then examine closely under good lighting.

    Ask your local welder for weld inspection dye.....like Magnaflux.....then crack test with the coloured dye indicator.

    If possible take the mast down. This is the only way to inspect all fittings. Turnbuckles, tangs, spreader roots.

    Another highly stressed, prone to failure, piece of rigging is the head stay terminals both aloft and on deck.

    http://www.magnaflux.com/ProductOverview/Penetrant/tabid/96/Default.aspx
     
  5. gonzo
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    gonzo Senior Member

    Magnaflux does not work on Stainless. It needs a magnetic medium like carbon steel or nickel. There are dyes to check for cracks. I think that in racing rigs that have a lot of tension, metal fatigue is a problem. On a cruising rig that is not stressed as much, corrosion is the main problem, if any. Hanging bridges, for example, are sized to not have loads that cause fatigue and will last centuries if well maintained.
     
  6. michael pierzga
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    michael pierzga Senior Member

  7. BATAAN
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    BATAAN Senior Member

    Totally concur with this assessment. SS has a 10-15 year life, then is ready for scrap, though can have a longer life if grossly oversized for the job.
    I have re-used galvanized rigging on the JOSEPH CONRAD at Mystic Seaport that was at least 70 years old and perfectly good under its serving and tar.
    Repeat, galvanized steel wire 70 years old was in excellent order and did not need replacement.
    SS and its various compression (swage etc) fittings are subject to micro-cracking and crevice corrosion, among other ills.
    Galvanized wire rusts, but that is very controllable, more so than the problems of stainless.
     
  8. urisvan
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    urisvan Senior Member

    does magnaflux not reveal the cracks on ss?

    regards
     
  9. michael pierzga
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    michael pierzga Senior Member

    http://www.magnaflux.com/Portals/0/.../Spotcheck~reg_Kit_Operating_Instructions.pdf


    Many times you can spot defects by simply cleaning the surface, them using your eyes and a magnifing glass to closely inspect. .

    Stop by your local Stainless steel welding shop. They normally dye test presion constuctions and may be able to give you a local dye product.

    If you have the rigging off your mast take it in your hand and give it a sharp twist and a bend...often a fatigued wire strand will break before your eyes.

    If the mast is standing, clean the rigging terminals very well of all rust stains.... do not use polish only a fine 3m scotchbrite pad, and a toothbrush... then go home for two weeks. If you return and again see a rust bleed forming you have a cracked terminal .


    Something to consider is that a mast , boom, sails , furlers, electronics package is a very expensice piece of equipment. The stainless steel rigging is the cheapest component on the structure. When in doubt .......replace. I recently replaced the verticle rigging on a half million euro mast...the entire new rigging package was 22 thousand euros. This is a very small cost fraction.
     
  10. michael pierzga
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    michael pierzga Senior Member


    http://www.magnaflux.com/Portals/0/.../Spotcheck~reg_Kit_Operating_Instructions.pdf
     

  11. gonzo
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    gonzo Senior Member

    Magnaflux is a brand name, but it is loosely used for magnetic testing of cracks. Other brands were making dyes for testing non-magnetic materials and now Magnaflux has a product for that too. If you are in the industry, that is such a common use that people don't get confused.
     
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