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  1. #1
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    Jan 2020
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    Post stainless steel HELP

    Hi all,

    I'm having a problem with my stainless steel railing stairs as some areas showing cloudy black, any idea how to get rid of it .

    I will attach pictures so things will be clear.

    Regards rail 1.jpgrail 2.jpg

  2. #2
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    Looks to be very highly polished, are you sure it’s not chrome plated ?

    On the planet earth there are some places that experience unusual atmospheric conditions and or pollution. Do you live in one of these places.
    An updated location in your profile may result in better answers.

  3. #3
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    I'm at a point if Members can't/won't put in a town/suburb and state, I won't respond.
    To me it looks like pollution of some sort, is it hard to clean off?
    To grow old is mandatory, growing up is optional.

  4. #4
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    Quote Originally Posted by KBs PensNmore View Post
    I'm at a point if Members can't/won't put in a town/suburb and state, I won't respond.
    To me it looks like pollution of some sort, is it hard to clean off?

    yes , i tried cleaning it with stainless steel cleaner , but with no luck

  5. #5
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    Quote Originally Posted by droog View Post
    Looks to be very highly polished, are you sure it’s not chrome plated ?

    On the planet earth there are some places that experience unusual atmospheric conditions and or pollution. Do you live in one of these places.
    An updated location in your profile may result in better answers.

    not sure if its chrome plated , but polished to a mirror finish , any idea how to get rid of it , its indoor stair railing .

  6. #6
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    Dec 2005
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    South Australia
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    It may well be staining from the welding, in which case you need to pickle and re polish look here http://www.worldstainless.org/Files/...ickling_EN.pdf

  7. #7
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    Alexandra Vic
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    From the location information (Middle East), I am guessing that you are close the coast and in a marine environment.

    I used to be involved with making metal furniture frames for indoor and outdoor furniture, including a lot of mirror polished stuff. In Australia we would recommend using 316 grade stainless for anything near (with 15km) of the coast or major rivers or lakes, as it is marine grade and capable of handling the damp environment without dulling, corroding, or showing water spots. Once you get away from coastal (or river/lake) humidity, it is economical to use cheaper 304 grade stainless steel, but as a minimum this will show water spots and dulling on mirror surfaces if they are exposed to rain or other moisture and it is allowed to sit on the surface.

    Mirror polished work like yours generally requires each component to be fully mirror polished prior to welding, very careful handling during welding, and polishing again after welding to eliminate any scratches etc imposed on the material. The welding process will create heat dark discolouration around the welds which either need to be polished out mechanically, or processed chemically to effectively bleach them off the surface.

    The most obvious thing in your photos (apart from the staining) is the fact that the upright tubes are 'fused' (TIG welded without adding filler metal) to the base rail on only one side of the upright, and simply butted to to rail otherwise, leaving an unsealed and porous joint. The fabricators appear to have done a fair but not great job on cleaning up the discoloration around the weld, probably combining chemical cleaning and repolishing. However because the uprights are not fully welded it appears that the chemical cleaning solutions have entered into the inside of the tubing through the unsealed joints and have not been able to be properly flushed out. The remnant cleaning material has then started to react with the interior surface of the tube, producing the staining material as a byproduct. This has then accumulated on top of the rail inside the tube, then bled through the unsealed portions of the joint and stained or etched the rail.

    How long has the railing been place, and is it possible to refer the issue back to the builder/fabricator? I believe that the only solution to the problem would be to repolish the railing, which would be awkward and very messy in situ. Ideally, I would have preferred to see the uprights welded all round rather than just on one face. Certainly this would have increased the discolouration due to welding, but it would eliminate ingress of cleaning materials into the uprights, subsequent corrosion, and bleeding corrosion products back onto the rail, and the fabricators seem to have the weld cleaning process reasonably well in hand.

    Hope this explanation helps you.
    I used to be an engineer, I'm not an engineer any more, but on the really good days I can remember when I was.

  8. #8
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    Jan 2020
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    Australia
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    Quote Originally Posted by ssniper View Post
    Hi all,

    I'm having a problem with my stainless steel railing stairs as some areas showing cloudy black, any idea how to get rid of it .

    I will attach pictures so things will be clear.

    Regards rail 1.jpgrail 2.jpg
    If your stainless steel welds are black on the surface, and you've confirmed that you have adequate gas shielding and the base metal is clean, then you're barbecuing your base metal. You're either moving too slow or using too much amperage.

  9. #9
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    Quote Originally Posted by malb View Post
    From the location information (Middle East), I am guessing that you are close the coast and in a marine environment.

    I used to be involved with making metal furniture frames for indoor and outdoor furniture, including a lot of mirror polished stuff. In Australia we would recommend using 316 grade stainless for anything near (with 15km) of the coast or major rivers or lakes, as it is marine grade and capable of handling the damp environment without dulling, corroding, or showing water spots. Once you get away from coastal (or river/lake) humidity, it is economical to use cheaper 304 grade stainless steel, but as a minimum this will show water spots and dulling on mirror surfaces if they are exposed to rain or other moisture and it is allowed to sit on the surface.

    Mirror polished work like yours generally requires each component to be fully mirror polished prior to welding, very careful handling during welding, and polishing again after welding to eliminate any scratches etc imposed on the material. The welding process will create heat dark discolouration around the welds which either need to be polished out mechanically, or processed chemically to effectively bleach them off the surface.

    The most obvious thing in your photos (apart from the staining) is the fact that the upright tubes are 'fused' (TIG welded without adding filler metal) to the base rail on only one side of the upright, and simply butted to to rail otherwise, leaving an unsealed and porous joint. The fabricators appear to have done a fair but not great job on cleaning up the discoloration around the weld, probably combining chemical cleaning and repolishing. However because the uprights are not fully welded it appears that the chemical cleaning solutions have entered into the inside of the tubing through the unsealed joints and have not been able to be properly flushed out. The remnant cleaning material has then started to react with the interior surface of the tube, producing the staining material as a byproduct. This has then accumulated on top of the rail inside the tube, then bled through the unsealed portions of the joint and stained or etched the rail.

    How long has the railing been place, and is it possible to refer the issue back to the builder/fabricator? I believe that the only solution to the problem would be to repolish the railing, which would be awkward and very messy in situ. Ideally, I would have preferred to see the uprights welded all round rather than just on one face. Certainly this would have increased the discolouration due to welding, but it would eliminate ingress of cleaning materials into the uprights, subsequent corrosion, and bleeding corrosion products back onto the rail, and the fabricators seem to have the weld cleaning process reasonably well in hand.

    Hope this explanation helps you.
    thanks for your reply , but would you recommend me what tool and pads to use to polish them , as my fabricator using angle grinder with polishing wheel and blue rouge and he can't reach tight spaces

  10. #10
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    Jan 2020
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    Middle East
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    Quote Originally Posted by China View Post
    It may well be staining from the welding, in which case you need to pickle and re polish look here http://www.worldstainless.org/Files/...ickling_EN.pdf
    thanks for your reply , but would you recommend me what tool and pads to use to polish them , as my fabricator using angle grinder with polishing wheel and blue rouge and he can't reach tight spaces because of a big machine and pads

  11. #11
    Join Date
    Sep 2012
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    York, North Yorkshire UK
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    Default

    Hi Ssniper.

    I would find another fabricator if he is using an angle grinder for that job !

    A Dremal with a polishing mop could easily get it there.
    Best Regards:
    Baron J.

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