Gold electroforming
Gold electroforming: chemistry, design and fashion
Electroformed gold alloys
Gold electroforming is a well-established gold jewelry producing technique in the business, this technique gives the possibility to create light-weight jewels with an outstanding geometry freedom, and at the same time alloys with a great mechanical strength, fundamental to create jewels such as bracelets and fasion accessiories. This technique is composed of many phases.
Creating matrices in low-melting alloy and models preparation
Jewels are designed with computer modelling, starting from this the designers create models
(or print them) made in wax or brass. These models are put inside particular silicone rubbers
that adapt themselves to the shape of the jewel, so that inside of them a hole with the shape
of the jewel inside of it is created.
Models are taken out from the silicone rubber, inside of them there are the hollows that
reproduce the same shapes of the jewels; after this, rubbers are engraved and, using a
very particular spin-cycle oven, a low-melting-point alloy is put inside of them so that
the alloy fills up the hollows left inside the rubber by the model. Once the oven is
cold, rubbers are opened and identical copies of the jewels are inside of them, they're
called matrices.
Before getting electroformed, matrices are coppered with a specifical plating bath,
so they're put in a frame made of conductive metal and then in a copper plating bath.
Electroforming
After plating, a frame with identical coppered copies of the jewels onto it is obtained.
The frame is now ready to get into the electroforming machine, this is a completely automatical
process managed by the machine's software; the workmen gives the main input variables in the
machine, that are the jewel's karat and the weight that every piece should be. These inputs
are computed by the software that manages every aspect: working temperature, frame pilotage,
working time and currents. Once the process is finished, the frame can be taken out from the
machine and the frame has to be coppered again to get through the next part of the process.
Emptying and jewel finishing
After being coppered, the pieces are taken out from the frame. At this moment is necessary to
get out from the pieces the low-melting-point alloy inside of them, so the pieces need to be
holed in their surfaces and they're put inside a spin-cycle oven equipped with special disks,
so that pieces are empty, so that shells in gold and copper are obtained. These shells
get treated in a specific acid bath, so that the copper layers formed in plating baths are
taken out from the alloy. With this last emptying treatment, what we obtain are the shells
in gold alloy formed with the electroforming machine. This shells are treated in a specific
oven, so that the alloy - formed in an electro-chemical way - gets a high mechanical strength.
The jewels are now ready to get polished and finished, and are ready to be put on.
Further informations
Interested in gold electroforming? Contact us!
ESA s.r.l. gained a twenty-years experience in gold electroforming,
from plating solutions, develpoed in its laboratory, to a complete copnsulting
service to give technical assistence on every process' part of the gold electroforming
producing technique.