Tarnished Fisher brass knobs: what is best to polish them?

Discussion in 'Fisher' started by monkboughtlunch, May 1, 2017.

  1. monkboughtlunch

    monkboughtlunch Super Member

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    1,370
    What do folks use to restore tarnished brass knob covers on their Fisher 400,500B/C,800B/C series tube receivers? Is brasso a good choice?
     
  2. Trojan4Life

    Trojan4Life Active Member

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    I milled a flat on a piece of steel, then put the knob with cover and turn it in a lathe, use a fine grit of sandpaper to polish it.

    Fisher.jpg
     
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  3. larryderouin

    larryderouin Do I get Food, Med's, or more gear this Month? Subscriber

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    Dremel with buffer wheel, and some Mother's mag polish. Just about any metal polish is fine. The more tarnished or corroded they are, the longer you leave the polish on (5 to 20 min) then buff it off leaving a shiny cover. The Navy actually banned Brasso back in the 50's for cleaning torpedo tube inner doors. Seems a few C.O.'s were making the Torpedomen shine the tube doors daily to the point the C.O could see his reflection at about 10ft. The problem was that Brasso is fairly abrasive, and the Inner doors were being worn down thinner and as such would not take sea pressure below periscope depth! So now they are polished in the manufacturing shop, and given roughly 20-25 coats of lacquer. The lacquer doesn't eat into the bronze, and it stays shiny with a damp cloth.

    Ask any MARINE what the most reviled item in his cleaning kit is and he'll tell you BRASSO!
     
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  4. gadget73

    gadget73 junk junkie Subscriber

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    Newer Brasso also has a formula that includes ammonia, and you don't want ammonia on Bakelite knobs. Reasonably sure those knobs are Bakelite anyway. Ammonia is one of the few things that will damage it. If it smells like a cat's litterbox, thats the stuff it won't like.

    I like the Mother's mag and aluminum polish. No ammonia smell.
     
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  5. fred soop

    fred soop Super Member

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    A couple of days in vinegar water followed by 600 grit sandpaper and wire brush. Might want to remove the metal spring from inside before soaking.

    1409
    [​IMG]

    1411
    [​IMG]
     
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  6. thomo57

    thomo57 Super Member

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    ☝️I'm not an expert but l wouldn't use sandpaper.
    Looking at my Fisher it has textured knobs and l thing sandpaper would be very harsh.
    A bit like polishing vintage coins.
    I'll stick with the patina look
    Soft brass brush maybe okay
     
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  7. Oscar23

    Oscar23 AK Subscriber Subscriber

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    Autosol for brass works great
     
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  8. fred soop

    fred soop Super Member

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    1,776
    600 grit is almost like a polishing cloth compared to more coarse grits. It was also used very lightly with frequent checking of the result.
     
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  9. Trojan4Life

    Trojan4Life Active Member

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    The knobs had the patina (corrosion) removed in 2013. The photo was taken last Monday. The question was asked regarding how tarnished Fisher knob covers were restored, not opinions.
     
  10. thomo57

    thomo57 Super Member

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    So yours was advice and mine was an opinion:idea:
    I advised the original post that sandpaper might not be a good alternative.
    The faceplates of mine have textured finish and sanding them would be like polishing old coins.
    You end up destroying what was there in my opinion
    Are you serious in that you felt it your obligation to pick my post out for your critique of what an opinion and advise is
    Talk about fun police:thumbsdown:
     
  11. Trojan4Life

    Trojan4Life Active Member

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    That's why the picture was attached- that's what worked for me. I use the amp everyday and haven't had any corrosion since I sanded the knobs in 2013.
    It's not advice- it worked. Advice is subjective, somewhat opinionated.

    Good eye, mate!
     
  12. larryderouin

    larryderouin Do I get Food, Med's, or more gear this Month? Subscriber

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    Guys; remember.........ALL AUDIO, NO ATTITUDE! If you have to argue points, please take it to PM's or agree to disagree.
     
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  13. larryderouin

    larryderouin Do I get Food, Med's, or more gear this Month? Subscriber

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    Gadget; as I recall Brasso has always contained ammonia. Bootcamp in San Diego 1973. The Admin bldg had a brass or Bronze 8-10ft. model of the Missouri. It got daily Brasso applications by members of the punishment details. Bunch of recruits would spend 6-8 hours bringing this monster to a hi shine. You could smell the ammonia from the brasso (literally buckets of the stuff) 100ft downwind when the front doors opened! GAWD AWFUL SMELL. Like 1000 cats pee'd on it!
     
  14. Trojan4Life

    Trojan4Life Active Member

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    Aye-aye, Captain!
     
  15. monkboughtlunch

    monkboughtlunch Super Member

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    Thanks for all the advice folks. Trojan4Life - that's a beautiful KX200. Those knobs are identical to my 400 receiver.

    Where I'm stumped is: how do you polish the chamfered edges (i.e. the sloped brass edges) on these knobs without damaging the brown plastic of the knob? I've illustrated chamfers below with arrows.

    Fisherchamfer.jpg
     
  16. monkboughtlunch

    monkboughtlunch Super Member

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    Did you pry the brass off the plastic before soaking in vinegar? If not, does the vinegar eat at the plastic?
     
  17. MikeRam

    MikeRam AK Subscriber Subscriber

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    Location:
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    I have used Brasso on my knobs and they seem OK. I also polish the chamfered edges and then scrub off any Brasso residue with dish soap, warm water, and a toothbrush. To keep the shine on your knob brites, you might want to clean them and then remove them from the knobs so that you can spray a couple of lacquer coats on them. After the lacquer is dry, glue them back on. I lacquer the chamfered edges with a very thin brush.

    Mike
     
  18. Trojan4Life

    Trojan4Life Active Member

    Messages:
    422
    Hello Monkboughtlunch- I took a piece of ~1/4' diameter steel, milled a flat on each end corresponding to the size of the D-hole on the two knob pieces and carefully sanded with ~1000 grit sandpaper with the steel piece mounted in a lathe. You don't need to sand for very long (shouldn't sand too much), but with a fine grade of sandpaper it shouldn't be a problem.

    The vinegar solution shouldn't eat through the plastic.

    See this posting #10: http://audiokarma.org/forums/index.php?threads/breaking-in-my-new-fisher-kx200.612108/
     
  19. fred soop

    fred soop Super Member

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    1,776
    No damage to the plastic (as you can see in the photo). Looking back, the metal springs in the holes should have been removed, but no serious damage.
     
  20. ncwalz

    ncwalz AK Subscriber Subscriber

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    Location:
    Alberta, Canada
    The glue holding the brass cap is not very strong and I've removed several from the plastic for better refinishing of the brass. I usually can push the brass caps off with a small screwdriver pushed up the shaft hole. If they don't come off easily I soak the knob in hot water for a few minutes and try again.
     

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