How to apply 24k gold Kumboo on Metal Clay or Fine Silver

Keumboo on Metal Clay or Fine Silver
Keum-boo is the art of bonding pure gold foil over fine silver.  As the fine silver and 24k gold molecules heat up on a hotplate, the two metals are joined through the process of burnishing the metals together. The two metals bond by sharing oxygen molecules.

Materials

• Finished fine silver item (PMC or fine silver)
• 24k gold, 23 ½k, or 23k (can be purchased from Allcraft tools (212) 279-7077)
• Hot plate - with high, medium and low settings or a Ultra Lite Kiln with a coil cover
• Klyr Fire by Thompson Enamels or thinned Elmer’s Glue
• Small craft paint brush
• Burnishing tool
• Fine tweezers
• Heat resistant gloves (lightweight leather gloves)
• Long tweezers (12")
• Heat safe work area  or fiber board
• Small cup of water
• Paper towels

Note

Gold leaf is less expensive than gold foil because it is much thinner. This thinness also makes leaf more difficult to handle. It also requires the application of several layers of leaf to obtain the same appearance as foil.Gold foil is available through the PMC Connection at www.pmcc.com or by phone to Allcraft tools.

The Process 

Precondition: The silver item (PMC) piece is already, fired. Do not brass brush, burnish, or tumble the PMC. All areas that will have gold applied must be burnished.

• Align all tools so that they are easily accessible, 
• If needed, place a metal cover over the hotplate so as  to give it a smooth even heating surface. I use a sheet of think copper. 
• Preheat the hotplate to high.
•  Its up to temperature when a toothpick burns when placed against the burner.
• Apply watered down glue to the first area to have gold applied to it. 
• Place the gold foil inside a folded sheet of paper. 
• Cut the shape out with the foil inside the paper. 
• Remove the gold from the protective paper using tweezers and place it on the wet glue.  You can also pickup the gold with a wet craft brush and place it on the metal by painting the foil down against the metal.
• Smooth the foil against the metal using a craft brush. 
• Place the metal piece on the hotplate using tweezers. Allow it to heat up to temperature. 
• Hold the piece with long tweezers, gently dab at the gold with a burnisher.
• You will know its up to temperature (650˚) when the gold starts sticking down onto the metal.
• Apply even strokes across the gold so that every millimeter is burnished to the silver. 

Notice that the gold is shiny where it is burnished to the silver. If the burnisher becomes too warm cool it by dipping into water and then drying it with a towel. 

• Repeat the process of applying the gold to the silver as wanted. 
• Finish the piece by burnishing with a soft brass brush with soapy water. 

 Notice: Re-firing the PMC in the kiln or with a torch over 1110˚ allows the gold to alloy with the silver causing the gold to disappear!