Mould, mend and make

September 17th 2016

The method that I am going to share with you today can be used in some cases to give that old piece of jewellery a new lease of life. It does not suit all pieces but when it does it can make the restoration process far more affordable.

The starting point

For this method to work the piece of jewellery needs to still have enough detail so that it can be redefined, traced over. By that I mean finer shapes and outlines need still be visible to a degree. What I am referring to here will become a little clearer as we progress through this example.

This silver Elephant ring my customer wanted in gold. In general the lines and marking on the top of the ring for the elephant and tree branch needed to be redefined, sharpened up.


Other things we need to mend

Some more major areas to be repaired were the band was too thin and the inside of the ring which had been hollowed out. Fortunately for this process neither of those areas had any detail other than general shape.

Creating the mould

Knowing that I would be replacing the band I removed it from the silver ring and then created a mould of the remaining top half. I attached some supports to the top of the ring and then packed it in soft rubber that cures on high heat. Once the rubber is cured the mould is then split into two and the ring removed as shown below.

The base attached to the ring in the previous step would create a cavity that would allow me to inject wax into the mould and give me an impression of the ring.

Doing some mending in wax

With the wax impression I could now add a thicker band and build up the inside of the ring by melting wax onto it. I could also remark some of the details in the top using engraving tools.

Turning that wax into Gold

To turn that wax into gold we set up the ring inside a flask that is then filled with heat resistant investment enclosing the wax.

You can see here the flask now filled with the white heat resistant investment. On this day I would be casting 3 flasks.

Once filled the flask is left to stand. Before placing in an oven at high heat the rubber base is removed exposing the wax so that it can dissipate from the flask once it reaches melting temperature and higher.

This photo of a flask that has been in the oven for a while shows the wax melting onto the rods below.

As the oven temperature rises any remaining wax is burnt out leaving a cavity in the flask the same shape as the ring. The flash from my camera hides it but the metal in this picture is red hot.

In the next photo you can the see the red hot precious metal after it has been injected into the flask.

Comparing the old to the new

To divest the ring the hot flask is plunged into water. As the powder falls apart the new metal ring is exposed and ready to be cleaned, more details redefined and then finished. The new 18ct yellow gold ring can be seen here next to the much thinner original band I removed at the start from the sterling silver original.

The inside of the ring is also void of any cavities and now totally solid.

All done and a lot heavier

The transformation of this ring took it from a weight of 3.7 grams in sterling silver to 6.5 grams in 18ct yellow gold. This increase in weight is due to both the repairs/modifications done and also the denser properties of 18ct gold.

This method is not suitable for all pieces but if there is enough detail left in an old piece of yours it might make a restoration a more affordable option compared to making the ring from scratch.

Info, Restore, RingsDavid Taylor