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Cleaning pitted metal

Discussion in 'Steam Traction' started by Corbs, Apr 13, 2019.

  1. Corbs

    Corbs Member

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    Was wondering if anyone out there had any tips on cleaning pitted metal?
    The lower half of Portbury's tanks are new, but the upper section is original, and soot collects really badly up there, it's really hard to shift it.
    I was wondering if there was a specific method or product I could use?

    Many thanks
     
  2. K14

    K14 Member

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    Grit Blaster... If you have the budget (and a bijou tent-ette to help prevent the grit from getting *everywhere*).

    If that's not an option, then a needle gun followed up with an angle grinder fitted with a knotted cup brush.

    Pete S.
     
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  3. jnc

    jnc Member

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    It sounds from the above as if the issue is not corrosion removal (for which sand-blasting is the best way to go), but just plain dirt? For that I'd recommend a brush with short stiff bristles, and press it more than horizontal movement; don't have any particular cleaning agent to recommend, past what will work well on the same grup on a flat surface.

    Next time you have the tanks off, though, after blasting, paint such surfaces horizontal, with a heavy coat(s) of paint, that will tend to fill the holes some, and reduce the difficulty with the reduced depth.

    Noel
     
  4. Corbs

    Corbs Member

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    Ah, sorry! I should have clarified this is day-to-day cleaning rather than restoration work, though I will make a note in case useful for the next overhaul/repaint.
    Would the brush with stiff bristles risk damaging the paint? It's an enamel finish in light grey.
     
  5. jnc

    jnc Member

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    Now that I think about it, probably a better approach for your application is to use car body filler, after blasting, to fill the pits (apply with a large putty knife or similar, which will fill the pits to the level of the surrounding metal; like using spackle to fill divots in interior walls, etc); that will give you a perfectly smooth surface, better for cleaning. (I have used the paint approach on pitted computer racks I was restoring, but some pitting remains; not an issue for my application, which is stored inside, and for which perfect surfaces aren't, to me, critical - for a number of reasons, e.g. painted in flat black, so you have to really look to see it.)
    Perhaps; there's no perfect answer, though, I suspect. (E.g. a pressure washer might damage the paint, too.) With the brush, one can modulate the force one applies, to hopefully minimize the scratching. The bristles have to be pretty stiff, so they can apply force at the bottom of the pits, to remove the dirt; soft bristles would just fold up. But they shouldn't be too hard a material; i.e. nylon or such, not steel.

    Also, let the grup 'soak' in whatever fluid you're using to clean as long as you can; that may make it easier to remove. (I say 'may' because it's not guaranteed to help; I've soaked 'barn find' computer backplanes for a week, hoping to make the grup on them come off easier, but it's not clear that it helped much.)

    Noel
     
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  6. martin1656

    martin1656 Part of the furniture Friend

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    Pressure washing is ok but cover up any journals etc you don't want for force any dislodged grit etc into bearing surfaces or get water into axle boxes , use a degreaser and let it soak in, repeat as many times as needed its highly likily that the surface of the paint will have been effected by the soot and general muck, a tip, a smooth surface is easier to keep clean, also and next time you decide to repaint her, fill the imperfections and use etching primer and filler primer and get the surface as smooth as you can, it also makes for a better finished paint job and one that you will find will resist the muck, if regularly cleaned
     
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  7. Steve

    Steve Part of the furniture Friend

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    I've found traffic film remover is pretty good at getting rid of the grime.
    If you are ever at the stage of painting such a surface, Williamsons do a brushing filler which is good for sorting out such surfaces. Paint it on then give it a wash with a diluted paint (of any colour) Once this is done, sand it down until all the paint wash has disappeared and you will have a smooth finish good for painting. If you can't get rid of all the wash, then you need more brushing filler on the area concerned.
     
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  8. Corbs

    Corbs Member

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