Skull Ring Diamond Eyes
Helen wanted an exact copy made of her husbands silver skull wedding ring.
This was a surprise for their 15th wedding anniversary (crystal), she asked me to set two diamonds into one of the skulls eyes for him. The ring didn’t fit him anymore, and he hadn’t worn it in a while. This allowed Helen to post it to me, ensuring the surprise was kept a secret! The best way to produce a replica of a piece of jewellery is to use the ancient art of Lost Wax Casting.
Here is how we used Lost Wax Casting to create the replica in 14ct rose gold, the ring also needed to be sized down to fit, so it was compressed after being cast in gold, but before the diamond eyes were set.
The first step is to prepare a rubber mould to encase the original silver ring in. You can see the rubber mould used to create a copy of his original silver ring. The first half of the rubber is cut and pressed into the metal casing, then the silver ring is filled with the same rubber. You will notice that the silver ring has a bar of silver welded to it. This will create the sprue – the part where the liquid gold will flow into the mould when being cast.
A second sheet of rubber is placed over the top of the ring, and the metal case is closed. The rubber is heated and subsequently melts into every part of the ring. The rubber is left to cool and then cut in half lengthways. This is done very carefully with a sharp scalpel, the rubber is very flexible, and its bent out of the way as its slowly cut away.
Then the original ring is removed. You can see the details of the skulls inside of the rubber mould. Getting this part of the process right, means that the wax copies, and in turn, the gold one, will be an exact replica.
Both halves of the rubber mould are held together, and liquid wax is squirted inside of the mould. Once the wax (blue version in the photo below) is cold, the mould is opened and the wax copy is carefully removed. Because this ring is quite a fine design, the wax kept breaking as it came out of the rubber mould. Our Mark was able to use a soldering iron to re-attach the pieces so the ring could be cast in one piece.
Once the wax replica is ready, it is attached to a main sprue; similar to a tree trunk. The additional smaller sprue that was attached to the original silver ring, creates one of the ‘branches’ for this wax ‘tree’. The job of the sprue is to create pathways for the molten gold to flow through, on its way to the actual ring part of the mould.
The wax ‘tree’ is made by hand and then covered with a metal tube. A substance called ‘investment’ (similar to plaster of paris) is poured over the top and left to dry out for 24 hours. The whole thing is heated and the wax runs out of a hold in the bottom and is ‘lost’. (Lost Wax Casting).
Now there is a recess inside, exactly the same as the original ring, with the pathway (sprue) for the gold to flow through.
Molten gold is ‘thrown’ into the mould and centrifugal force is used to spin the metal into every tiny detail of the mould. Everything is now very hot, and once spun, is plunged into cold water. The investment can’t cope with the temperature change, and bubbles away.
Leaving the gold ‘tree’ standing proud. The sprue is cut away with pliers and returned to the pot for re-melting in the next cast.
The silver is the original ring, the blue is the wax copy of the silver ring (created in the rubber mould) and the rose gold is the new replica of the original silver one (created by Lost Wax Casting).
The new rose gold ring was sent to Birmingham Assay Office for hallmarking, and then compressed down a finger size, so the new ring would fit her husband. Compressing or stretching rings can only be done to bands without stones set into it.
The final stage of this creation, was to hand set 2x diamonds into one of the skulls eyes, and give it a good clean and polish.
Helen mentioned that they would give the original silver ring to their son, so Mark cleaned and polished it like new for him. Helen was thrilled with the results. Apart from the actual metal, smaller finger size, and diamond eyes, – there is no difference between the two rings at all!