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Thread: Polishing to a mirror shine - problem!

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  1. #1
    Join Date
    Apr 2011
    Posts
    103

    Default Polishing to a mirror shine - problem!

    Hi all,

    I keep getting a recurring problem when trying to polish silver ring shanks to a mirror shine. I am polishing by hand from 400, 600, 800, 1200 and then final polish with luxi blue and white using my Foredom.

    However, I keep getting a stripe down the middle of my ring shank where it looks like the sand paper/emery stick has not touched.

    I have tried polishing with the curve of the ring with a stick, and free holding sandpaper. I have tried going across the ring, I have tried doing a slant diagonally across!

    Every time I do it it looks like I have caught all of the silver with the sandpaper at each grade but when I go to polish if up - still have the stripe down the middle.

    The rest also looks unfinished too - so maybe I need to use further grades of sandpaper for a mirror shine?? But I am at a loss with my stripe!!

    My current ring has had 3 polishes and still does not look anywhere near mirror. I am a little scared to keep at it though as feel nervous about how much sanding you can do!

    Any ideas of what I am doing wrong???

  2. #2
    Join Date
    Dec 2009
    Location
    Central London
    Posts
    8,845

    Default

    If it is a darkish blue-grey stripe it is firescale. This is copper oxide and occurs fairly deep below the surface. The cause is too much concentrated heating with an oxidising flame (one with a sharp blue cone)

    The curse of firescale if you care about it, is that it becomes more visible the shinier you make the surface. So you can either settle for a matte finish, or keep filing, grinding and polishing until it has gone.

    These Scotchbrite polishers from Cooksons also work well for this, without being too destructive.

    http://www.cooksongold.com/Jewellery...prcode-999-ACR. Dennis.

  3. #3
    Join Date
    Apr 2011
    Posts
    103

    Default

    Arrr ok, thanks Dennis - I might have one of those in my pack of polishing bits I got with my dremmel or foredom.
    Will try this and see how it goes.

  4. #4
    Join Date
    Feb 2011
    Location
    Scotland
    Posts
    3,392

    Default

    Could you post a picture of your stripe so we have an idea before you attack it with anything else? Is it in the same place on every ring?
    Last edited by CJ57; 19-10-2014 at 10:11 PM.

  5. #5
    Join Date
    Sep 2014
    Posts
    2,067

    Default

    I started out sanding by hand and could never get a finish I was happy with no matter how hard I tried or how many instructions I read.
    I now use the Everflex rubber burrs on my pendant motor and haven't had any problems- unless it is fire scale when I found Dennis tip about the Scotchbrite to be a great one - I used that then back to the red then green Everflex.
    http://www.cooksongold.com/Jewellery...prcode-970-360

  6. #6
    Join Date
    Apr 2011
    Posts
    103

    Default

    Thanks all - yes it is Caroline - same place - down the centre like another band! I looks like I haven't 'hit it' with the sandpaper but I have sanded every which way to try! I might try machine instead of hand - thanks for the suggestions.

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