Does The Polished Brass Need Manual Polishing After Production?

Discussion in 'Materials' started by bburlin75, Feb 18, 2018.

  1. bburlin75
    bburlin75 Member
    Hi,

    I wanted to see if anyone who has experience with the polished brass could tell me if the material comes out even post production or if manual polish is needed?
     
  2. Frozenrain
    Frozenrain Well-Known Member
    This information may help you.
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  3. Shea_Design
    Shea_Design Well-Known Member
    Over polishing is usually the issue but only on fine details that can be erased on the wheel pretty quickly. Good luck! -S
     
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  4. UniverseBecoming
    UniverseBecoming Well-Known Member
    It's purely geometry specific. If you have something like a simple sphere it's going to come out absolutely perfect. Whereas if the geometry is something like a skull ring there will be places that are absolutely perfect and a few areas here and there, mainly in the recessed areas, that will have faint print lines with a spacing of 16 microns that are barely visible.

    Overall, whatever your geometry is I think you'll be impressed with the overall result.
     
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  5. bburlin75
    bburlin75 Member
    Thanks for your feedback!
     
  6. ZapWizard
    ZapWizard Member
    I have had odd shaped objects come out perfect multiple times. However anything that has a flat surface so far ends up over-polished. I think that odd shapes objects tend to get a bit more of a hand treatment, where flat objects seem to be held against a sander and then a large buffing wheel.
     
  7. Tuxu_HDS
    Tuxu_HDS Member
    Hi, I'm rather new in these parts and I lack some knowledge regarding shapeways' polishing methods.
    Are there any substances other than brass involved in the polishing process - like solvents, oils, ect...

    I intend my creation to a friend's wife(14k) and their baby cart(brass) so i'm a bit worried regarding safty issues.

    Does anyone has any concrete knowledge specifically regarding shapeways' polishing method?

    Thanks!
     
  8. ZapWizard
    ZapWizard Member
    @Tuxu_HDS:
    Most likely any chemicals used would be cleaned off before you receive the part. I just got a raw brass part in today, the part was dry and clean. No residues left behind. You can always clean it yourself with alcohol.

    You may want to educate yourself on Brass itself. Since it will of course remain long after any trace surface chemicals.

    I am not trying to scare you, just educate you. Brass has of course been used for centuries for jewelry. Brass is typically fine for items which you don’t have in constant contact with skin such as a necklace.

    Brass, or any other copper alloy actually has great antibacterial properties. Bacteria can’t live on a copper surface for very long. Some hospitals even switched to brass door handles due to this.

    Brass is a metal alloy with primary copper and zinc. However, brass can have small amounts of trace metals such as nickel and lead.

    Lead is not absorbed through skin, so brass is considered safe to handle. Again, it is not something you would want a baby putting in its mouth.

    Nickel can cause an allergic skin allergy in some people. I am sensitive to it myself, but handling brass typically doesn’t cause any issues. But I would not put it in my mouth or wear it with constant skin contact due to the nickel.

    Over a long time, contact with your skin oils and moisture can cause the copper content to tarnish and turn the skin around it green. This green color is not the copper or some metal absorbing into your body, but just the copper oxidating and remaining on the top layer of the skin.

    Plating such as 14K gold of course seals the surface and provides protection against tarnishing. But the plating is very thin. A plated ring for example can have the coating wear off mechanically. Plating is great for jewelry you only wear occasionally, but not for say a something you wear every day.

    Again, even with plating, it is not something to expose a baby to. The underlying brass is soft and teeth can wear through the plating in no time.
     
  9. Tuxu_HDS
    Tuxu_HDS Member
    @ZapWizard


    Thank you very much for the information!

    I am familiar with the corrosive properties of metals and alloys and patinas in general but was a bit apprehensive due to the fact that sometimes brass is coated with transparent polyurethane or other substances.

    Incase a the baby might gnaw on the pendant I'd be more worried over him choking while trying to swallowing it.
    I think I might put it out of my mind though since that brass part is suppose to be a baby cart adornment.

    I've sent Shapeways materials-team a question about their process through the service mail and I'll see what they have to add to it, just in case.

    Thanks again.

    P.S. - Loved the Pip-boy! :)