tungsten filled 1 kilo gold bar discovered in UK

Discussion in 'Gold' started by smokey, Mar 24, 2012.

  1. Byron

    Byron Guest

    What's the minimum weight/thickness that this can be used at?

    I take it it won't work on coins.
     
  2. projack

    projack Well-Known Member Silver Stacker

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    Thickness of 150 micron rolled gold tungsten bars still could be outside of the maximum limit of the XRF and the minimum limit of the ultrasonic test.

    Hit it with a thin nail cost you nothing and can not be fooled after density test like these expensive equipments.
     
  3. goldpelican

    goldpelican Administrator Staff Member

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    What do you mean by "minimum limit of the ultrasonic test" - are you saying a 150 micron gold coating over tungsten would defeat ultrasonic thickness testing?

    Not defending the test, I'm still waiting for equipment to arrive (will be a few weeks).
     
  4. projack

    projack Well-Known Member Silver Stacker

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    I am not an expert on ultrasonic machine but look to me on the video the test result on the screen shows only if you have a homogeneous solid material. Bubbles and crack would show up exactly the same on different metals, regardless of the metal.
    So if you are looking the screen 150 micron on the top wouldn't even show the first pixel with the gel on it.
     
  5. JamesG

    JamesG Member Silver Stacker

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    hi if its good let me know where you got one for $172 , as these xrf machines are not 100% and cost too much :D
     
  6. goldpelican

    goldpelican Administrator Staff Member

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    eBay - need to see if it's any good first!!!

    I think it would only be useful on bars, not coins.
     
  7. projack

    projack Well-Known Member Silver Stacker

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    The ultrasonic and XRF machines have different purpose. You can not replace one with the other.

    The XRF machines analgizing the metal compositions about 100 microns deep.

    The ultrasonic machines analysing the inner material designed to detect cracks and air bubbles.
    This is crucial for safety in industrial application like bridges airline parts, but also for smaller parts.
    The question is how close to the surface you can see with them?
     
  8. bron suchecki

    bron suchecki Active Member Silver Stacker

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    If you read my post, this quote answers the question - ultrasonic will reveal gold plated material.

    "The 1090 Flaw Detector allows you to look into the Bar for voids/defects as well as UT velocity which is determined the products elastic modulus i.e Tungsten Velocity is 5183-5460m/sec and Gold is 3,240m/sec. For example if you calibrate for Au then the testing Tungsten bar of the same thickness, the UT thickness would read approximately half the actual because of the speeding-up of the sound through the Tungsten."
     
  9. goldpelican

    goldpelican Administrator Staff Member

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    Just to clear it up - there's two types of ultrasonic testing - ultrasonic thickness testing, and ultrasound inspection.

    Ultrasound is what GoldMoney did - this looks for internal inclusions, cavities and cracks.

    The other sort is ultrasonic thickness testing - this measures the thickness of an item based on the expected velocity of sound - thick of it as a hobbit test - "there and back again". Basically a sonar ping to see how far away the opposite edge is. If the material isn't gold or silver, the calculated thickness will be grossly wrong.
     
  10. projack

    projack Well-Known Member Silver Stacker

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    I have an antique large pocket watch. The back cover is made of two plates of 10K gold with plate of composition between. If anything analyses this correctly I am interested.
     
  11. Nukz

    Nukz New Member

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    hehe nice, i got a old Patek Phillipe pocket watch i picked up a few years back at Camberwell market here in Melbourne it's a real beauty i should also look at this to find out if its real gold it definitely has the weight of gold not sure if you would even fake a pocket watch with all the gears.
     
  12. projack

    projack Well-Known Member Silver Stacker

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    Gold Patek Phillipe is worth a fortune if running.
    If it is a repeater you have really something special.
     
  13. bron suchecki

    bron suchecki Active Member Silver Stacker

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    Thanks, so I've used the wrong term in my blog post. :p
     

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