Brilliant, my dear!
The MINOR S is the smallest member of the Ersa product family. The largest market for the mini soldering irons: Turkey, second-largest exporter of gold jewellery. Every year, Ersa dispatches around 1,000 MINOR S to the jewellery industry on the Bosporus.
In a shopping centre in Istanbul, dozens of jewellery makers working behind steel doors produce all kinds of gold jewellery – chains, earrings and rings. The production of a gold ring requires a ceramic mould, which is initially cast as a blank. This involves pouring melted wax into a rubber mould.
Experience at their fingertips
In order to maximise production efficiency, as many blanks as possible are brought together in a “wax tree“. This is where the MINOR S comes in – with 5 watt heating power at a maximum temperature of ca. 440 °C. The blanks are set into the wax trunk – the MINOR S melts a mini hole in the wax tree, into which the blank gating is inserted and fixed within seconds through solidification. Practiced jewellery makers speed up this process by blowing on it. This takes a lot of dexterity as the position and spacing of the blanks need to match exactly. If the spaces are too small, breaks result, leading to reworking – if spaces are too large, the unit number is reduced. Above all, the angle has to be right to harmonise with the flow of the liquid metal.
Hardening at 800 to 900 °C
The casting mould is ready, now comes the glamorous part in the form of gold, silver and so on. The wax trees are moulded in a metal cage and in ceramic. The form is hardened in the kiln at 800 to 900 °C. The wax runs out of the ceramic form, making way for the liquid metal. When the necessary temperature has been reached, the hot mould is clamped into a pressure casting machine. The liquid metal finds its way into the cavities in the ceramic; the pieces of jewellery take shape – in the form of the wax tree, now in precious metal. The parts are released from the gate and pass on to finishing: trimming, buffing, polishing, mounting, engraving – finished. Nice to think that the mini-soldering iron Ersa MINOR S produces so many treasures!