removing stain from stainless

Discussion in 'Materials' started by Steve W, Jun 18, 2014.

  1. Steve W
    Joined: Jul 2004
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    Steve W Senior Member

    Im looking for ideas on how to easily remove the normal stains you get on stainless parts in a seawater environment, specifically, the standing rigging. All 12 1x19 cables are currently off and coiled up so what i would like to be able to do is immerse them all in some kind of solution in a small plastic paddle pool to soak, then rinse. I have tried spotless stainless product on some small parts and it did nothing and would not be practical for large scale stain removal anyway due to cost. So what im looking for is recommendations from anyone who has actually had success doing this. To be clear, i have thoroughly inspected the stays and we are only dealing with the normal stains from a marine environment, no rust down in the swages.

    Steve.
     
  2. rxcomposite
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    rxcomposite Senior Member

    Try Coca cola. They say it will remove stain from Chrome or SS. Not sure but I read somewhere Coke contains phosphoric acid. Phosporic acid I use to remove baked oil stain. Lime juice I use for aluminum.
     
  3. Steve W
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    Steve W Senior Member

    Ive tried coke on ss and just for the hell of it i tried it on some copper coins and it did nothing to either so i think it just an old wives tale, i also tried lime juice on the ss because citric acid is supposed to work but again, nothing.

    Steve.
     
  4. Mr Efficiency
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    Mr Efficiency Senior Member

    I read somewhere that bi-carb soda works to remove rust stain, how, I don't know.
     
  5. Steve W
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    Steve W Senior Member

    Thanks, i will give it a try and report back.

    Steve.
     
  6. jonr
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    jonr Senior Member

    Clean it well with detergent then put it in hot citric acid. This will passivate it. For me, it got rid of stains and kept them from coming back (albeit a different application).
     
  7. SukiSolo
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    SukiSolo Senior Member

    Maybe Oxalic acid? Not tried it for cleaning S/S but works to remove iron stains (if light) on timber reasonably well. It is the stuff in rhubarb leaves, but enough in the stalks so when you cook it, your saucepan looks super clean!.
     
  8. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Cleaning stainless is a pain in the butt, but really breaks down into the same thing as other metals, abate then polish.

    BarKeepers Friend is a commonly available cleaner, found in any supermarket. It's baking soda and a few other things, mostly an abrasive, some acids too though and it works, with enough elbow grease. Make sure you rinse well with this stuff as it'll keep "etching" if you don't You can try "NeverDull" wads too. A friend tells me that the Clorox "Magic Eraser" works too. The restaurant industry relies on Sheila Shine as the go to product. I usually see what acetone will do first, then move to abrasives, like baking soda.

    Once cleaned, you'll want to polish up the surface and you can use oils, but I find these just attract dirt, so I use a micro fiber cloth, on a buffer with bigger pieces.

    Really tough stains need nitric acid or a "pickling" treatment, which is hydrofluoric and nitric acid with a thickening agent. Be careful with some of these things, as it can burn the hell out of you.
     
  9. tom kane
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    tom kane Senior Member

    I have used 800 and 600 grit wet and dry automotive sanding paper for many stainless steel cleaning jobs (including my sink bench) in the Dairy and Automotive Industries for initial cleaning.
    Then buffing for a finer shine it is quick and does no harm and is the accepted way to polish and clean stainless steel. If you want a brighter shine then electro polishing is required. You can even start of the polishing with courser grit such as 240 grit.
     
  10. CDK
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    CDK retired engineer

    Phosphoric acid removes stains in approx 5 minutes, oxalic acid also works but is a bit slower. Vitamin C also is an excellent reducing agent, cheap and easy to obtain.

    The chemical approach is always temporarily, only polishing has a more lasting effect.
     
  11. Steve W
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    Steve W Senior Member

    Thanks guys, I have done lots of metal polishing in my life as I often fabricate custom fittings such as chainplates, bow fittings, mast hardware etc for boats, have it welded and then fettle and polish it myself. While this approach would be fine for smaller stuff like the turnbuckle parts and even the swage fittings it really dosnt seem practical for hundreds of feet of 1x19 cable. There are 12 stays averaging maybe 40ft each, hence the desire to just soak them all together in a solution in a small plastic kiddie pool. I do have some concerns about using an acid at too great a concentration as it will be a lot more difficult to rinse out of the inside of a cable vs just a solid part which is why im hoping someone else has already done this, specifically with cable and can suggest a proven concentration. I have done a few small tests with a commercial product called spotless stainless which is citric acid based and is supposed to be a brush on, rinse off product, for me it does absolutely nothing, very disappointing given the price.

    Steve.
     
  12. Yobarnacle
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    Yobarnacle Senior Member holding true course

    The coke treatment is in conjuction with aluminum foil.
    https://www.youtube.com/watch?v=7XCDz3HwfSI
    But try molasses water. Automobile restorers use it on rusted out body parts. Removes the rust but takes days of soaking. Leaves the metal clean and no etching of metal.
    https://www.youtube.com/watch?v=KZCFcxf5IBw
    I have used molasses to remove rust from old bolts so swollen with rust, you couldn't see the threads. I didn't reuse the cleaned bolts, but was abe to measure threads for new replacements.
    https://www.youtube.com/watch?v=8-gBAjEga1s
     
  13. jonr
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    jonr Senior Member

    Stainless steel is unique in that the proper treatment will remove the iron from the outside and leave chromium which will oxidize and protect itself. So you really want to use citric acid passivation, at least as a final stage. It takes awhile, even at high temperature.

    A coating of LPS3 after that might help too.
     
  14. Steve W
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    Steve W Senior Member

    Well, I tried muriatic acid (just because its easy to get) on some stained 1/2" clevis pins, I started with 20:1 dilution and then 10:1, 5:1 and finally it worked pretty well at 2:1. I think I want to try the citric acid because you can buy it easily in powdered form online for low bux. The key points for me are, do no harm, low cost and easy no scrub operation.

    Steve.
     

  15. tom kane
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    tom kane Senior Member

    A stainless steel wire brush works wonders cleaning difficult parts.
     
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