Casting
One master. Four hundred pieces that are all the same.
One master model becomes a rubber mould, and the mould becomes as many identical pieces as the order needs. It is the oldest idea in metalwork — lost wax — running on modern equipment.
The nine steps
Lost wax, which is roughly five thousand years old, running on vulcanisers and vacuum casters.
- 1
Master model
The original, in silver or brass, finished to the standard every copy will inherit.
- 2
Vulcanised rubber mould
The master is packed in uncured rubber and cured under heat and pressure, then cut open along a parting line chosen so the wax will release without tearing.
- 3
Wax injection
Molten wax is injected into the mould. Each shot is a wax replica of the master.
- 4
The tree
Waxes are assembled onto a central sprue like branches, so a whole tree fills from one pour.
- 5
Investment
The tree is set in plaster investment and left to cure solid.
- 6
Burnout
The flask is heated for hours until every trace of wax is gone and only the cavity remains.
- 7
The pour
Molten metal fills the cavity — by gravity, vacuum or centrifuge depending on the piece.
- 8
Break-out & cutting
The investment is quenched away, the tree recovered, and each piece cut from the sprue.
- 9
Filing & finishing
Sprue marks are taken down and the piece is filed ready for polishing and plating.
The one rule of casting
Whatever the mould records, it records for good
A scratch on the master is a scratch on all four hundred castings. A soft detail on the master is soft on every one. This is why the time goes into the master and into where the mould is cut — not into fixing pieces afterwards, one at a time, which cannot be done economically and often cannot be done at all.
Spend it on the master
An hour more on the original is an hour spread across every piece in the run. It is the cheapest hour in the whole job.
Cut the mould thoughtfully
Where the rubber is parted decides whether wax releases cleanly or tears a detail off every time.
Then it is arithmetic
Once the master and the mould are right, quantity stops being a quality question and becomes a scheduling one.
What to send, and what to tell us
A casting order goes wrong at the beginning or not at all.
Bring
The master model
Say
The metal and karat
Say
The quantity
Say
What happens after
Then it needs finishing
A casting comes out of the flask with sprue marks and a matte surface. What happens next is what decides whether the plating looks like anything.
Bring the master
Tell us the metal, the quantity and whether it goes on for polish and plate. We will tell you what the run takes.
Kanchwala Building, 3rd Floor, Room No. 28, 63 Dhanji Street, Zaveri Bazar, Mumbai 400003