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Thread: Need some assistance in taking out scratches in brass....

  1. #1
    Les
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    Need some assistance in taking out scratches in brass....

    Howdy all. Normally I'm pretty handy, but this hardware on this 5x7 stumped me. I was able to revive the brass pieces to look really nice, but there are still some tiny scratches. Is there a way to buff this out, or should I just throw up my hands, reassemble everything, go somewhere and photograph vs obsessing over minutia ? Are there any pro products that would involve a paste + drill/Dremel....or ? Thanks in advance.

    Les

  2. #2

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    Re: Need some assistance in taking out scratches in brass....

    To remove scratches, you always have to go back to the grit that would cause such a scratch. If you try shortcuts, you end up only with polished scratches. Or. . . you can sand much longer at a higher grit. As a compromise, I would start with 600 wet-or-dry sandpaper, with a hard backing like an eraser and some light oil--baby oil would be good, and go over the whole piece, as a flattening operation. Then try 0000 steel wool, and finally some polish. In general, you should always go in straight lines, in the same direction, not criss-cross--that way any fine scratches you leave will be organized and neat, and use a stiff backing when possible so that you don't round over edges, which is the sure sign of an amateur.

    If you want it to look nicest, at each stage do the whole piece, not just a small area, so that the whoe thing goes together.

  3. #3

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    Re: Need some assistance in taking out scratches in brass....

    What he said.

    A dremel doesn't really have enough torque to act as a buff. You really need a large 3/4hp motor for a buffer to do it right. a jewelers buff might work but a big one would definitely work great. You would still need to go through various grits but could do all the hardware in an hour or less probably, using a machine buffer.

  4. #4
    Jac@stafford.net's Avatar
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    Re: Need some assistance in taking out scratches in brass....

    An alternative is to go for a different look and have the part shot-peened for a luster rather than a fragile shine. Choose the technician carefully.

  5. #5

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    Re: Need some assistance in taking out scratches in brass....

    Quote Originally Posted by leszek vogt View Post
    howdy all...... Should i just throw up my hands, reassemble everything, go somewhere and photograph vs obsessing over minutia ?

    Les
    yes!

  6. #6
    IanG's Avatar
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    Re: Need some assistance in taking out scratches in brass....

    Wire wool then brass polish works extremely well, if needed use wet & dry paper first. I use both for aluminium and brass parts and you can get a perfect finish.

    Ian

  7. #7

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    Re: Need some assistance in taking out scratches in brass....

    How shiney do you want that brass to be ?
    If it's an old camera then leave the little scratches in as a badge of age, if you want a mirror like polish and take the scratches
    out then contrary to what EdSawyer said I use a Dremel with their Scotchbrite wheels ( # 511E ) , they shed like anything so get
    more than you think you need, I don't know why they don't offer bulk packs.
    One is beige ( coarse ) and the other is gray (fine ), the gray wheel does a great job at getting out fine scratches,
    hand polish with a metal polish, I use Presta Metal polish which I got at Pep Boys or Auto zone ( i forget ).

  8. #8
    Les
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    Re: Need some assistance in taking out scratches in brass....

    Thanks for the suggestions. Before I go to "0000" wool, I thought I'd try some sand paper (on the reverse side of the hardware). One fella on my hill gave me some 12,000 sandpaper....I was quite surprised that such even existed. Yes, it does shines up, but amazingly it still leaves minute scratches.

    Les

  9. #9

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    Re: Need some assistance in taking out scratches in brass....

    You're always going to have scratches; it's a fact of polishing something. However, you can minimize them by using progressively finer grits, whether it be sandpaper, emery cloth, or a liquid/paste polish.

    I can remember prepping metal samples for a Materials Science course in college, and we had access to whetstones of increasingly finer grit. After running through the 5 wheels (like polishing a diamond, and yes, diamonds have scratches!), the sample was like a mirror to the naked eye, but scratches were HUGE under magnification. Took time and effort to master the technique. Unfortunately, after all that polishing, we had to etch the metal with acid to bring out the crystal structure that would then be photographed under high magnification. Goodbye mirror finish!

    Keep in mind that you're removing metal in the process. If it's an old lens or other part, repeated polishing might compromise strength. Differential expansion between thich and thin walls might warp the light as it passes through the lens (though I suspect the lens would be fairly gone at that point). I'm simply recommending caution vs. your desired cosmetic effect.

    I'd recommend aluminum polish and plastic polish for your final attempts. I've used plastic polish to remove fairly deep scratches from acrylic sheets, leaving behind only the finest scratches. I've even used it on my glasses, without harming the prescription.

    I'd also recommend that you get a small piece of brass to practice on before attacking the piece in question. Fine-tune your skills - finger pressure, thickness of the paste, etc, before working on the actual piece. You can compare/contrast all of the suggestions to see what might work best for you. Keep in mind that brass is an alloy, so the results might be a bit different between the test brass and the actual brass due to variations in tin/copper content.

    Post some before and after pics to help others in the future!!
    Last edited by indy_kid; 5-Dec-2013 at 12:11. Reason: mis-entry

  10. #10

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    Re: Need some assistance in taking out scratches in brass....

    Quote Originally Posted by Leszek Vogt View Post
    Howdy all. Normally I'm pretty handy, but this hardware on this 5x7 stumped me. I was able to revive the brass pieces to look really nice, but there are still some tiny scratches. Is there a way to buff this out, or should I just throw up my hands, reassemble everything, go somewhere and photograph vs obsessing over minutia ? Are there any pro products that would involve a paste + drill/Dremel....or ? Thanks in advance.

    Les
    If there are large/deep scratches, sand them out with 600 grit paper used wet, then finish it with OOOO steel wool. Here's something to keep in mind: as long as all the marks are uniform and run in the same direction, it will look great - look at an old lens with a lacquer finish - not polished, but 'grained', and they look fine.
    The shinier you make it, the more apparent future marks will be.
    If you want dished out holes, rounded edges, and smeared engraving use a power buffer. Power tools take time, experience, and lots of ruined parts to master.
    One man's Mede is another man's Persian.

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