What is Keum Boo?


Keum Boo literally translates as "attached gold".
It is a thousands year old Korean technique that
bonds 24k gold to fine silver.  

It is a magical process that can be combined with many other jewellery making techniques to produce amazing designs!
Read on to find out how it works and the tools and materials needed...

How it works

Although many articles refer to Keum Boo as fusing the gold to fine silver, the gold actually attaches by diffusion bonding - it exchanges atoms with the fine silver to create a strong permanent bond, hundreds of times thicker than gold plating!

The bonding needs three things to work properly:
1. Heat - lower than the melting temperature of solder
2. Pressure - created by burnishing the gold foil onto the silver
3. Clean metal

As you can see from the Golden Butterfly pendant to the right a little gold goes a long way, making this a great way of adding the richness of gold to your jewellery without breaking the bank! 



    Tools and Equipment

    You will probably already have most of the equipment that you need for Keum Boo, for example:
    Soldering kit - for preparing the silver for Keum Boo and also helping to finishing your jewellery
    General jewellery tools including saw, files, hammers - to make the jewellery the Keum Boo is to decorate.

    You will also need tools for cutting the gold foil such craft paper punches, scissors, tracing paper, templates, plus a burnisher to brunish the gold foil onto the silver.

    The most important piece of equipment that you may not have is a heat source...

    Heat Sources

    The most important piece of equipment needed for Keum Boo is also the one that you may not already have - but don’t worry, there are a few different choices covering different budgets. Each has it’s own advantages and disadvantages.....

    Electric Hot Plate - cheap, easy to find but has a thermostat. Once the temperature has been reached the hot plate switches off and cools down, so you need to turn it off and back on again. A brass sheet needs to sit on top of the hot plate to provide a better work surface.

    Ultralite Kiln - far more expensive than a hot plate but lasts much longer. Designed specifically for firing small metal clay and small enamelled pieces and for Keum Boo. Separately bought brass lids are needed to sit on top of the kiln. The kiln takes longer to heat up than a hot plate but uses less electricity and holds a good steady temperature.

    Small Blowtorch - can be used to very carefully heat up the metal. Advantages are that you probably already have one and they aren’t very expensive to buy or run. However, you do have to be very careful when heating so that you don’t melt the gold foil, and often have to reheat a design halfway through.

    To see how the gold foil is cut and applied to the silver watch this chapter of the
    Golden Butterfly Pendant class
     - the first in the Keum Boo course!

    Looking for some more information?
    Click on the images below!

    And for weekly jewellery making tips and a place to share your work and ask for advice join The Jeweller's Bench Café facebook group!

    Joanne Tinley

    The Jeweller's Bench is run by Joanne  Tinley. She has been making her own jewellery for as long as she can  remember and left her first career as a school teacher to set up  business as a  jewellery designer and tutor nearly 15 years ago. She is  self-taught and like many people started with wire and beads. Learning  how to solder, however, opened up a whole new world of jewellery making,  one that she is keen to share! There is something so magical about  watching solder flow through a seam, joining  two pieces of metal  together smoothly.

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