Metal casting is a technique that can be dated back to the 3rd millennium BC and has sustained minimal changes since then.
From lost wax casting to sand and die casting, let us take you into a journey of discovery of the different techniques.
From metal forming to CNC milling, bending, turning, spinning and calandering, machines offer an incredible range of working with a versatile material like metal.
CNC milling process allows the creation of 3d generated drawings into a solid block of metal.
The sharp cutting tool attached to the machine arm moves through the metal trimming or drilling into the material.
This is very time consuming and expensive process and it is mostly used for small production batches, for prototyping or for small components.
CNC and machine turning use a lathe to create parts or whole furniture with cylindrical features: final parts with axial and radial holes, grooves and slots. A lathe is a machine tool used primarily to shape solid pieces of metal. While the workpiece is held and rotated by the lathe, a tool is advanced into the work causing the cutting action and the exceed material removal. The CNC turning process allows to automate the process as the live cutting tool is moved by the robot arm. The technique is mostly used to manufacture small furniture elements.
Laser cutting is a technology that allows metals and some non metallic materials to be cut with extreme precision.
A continuous cut is produced on 2d metal plates by moving the laser beam or workpiece as the referenced CAD file.
These processes can be used to form complex shapes out of different types of ductile metal tubings or metal plates.
Traditional machines bend the work piece into the shape of a die, and multiple bends and angles are possible.
Computer controlled bending is the evolution of the traditional method, where the process is carried out by CNC press brakes that can be programmed in its movements and angles.
Bending is used to fold metal sheets to an angular shape. Sheet metal calendering process is done thanks to machines called calenders that have a series of rollers whose axes are parallel to each other. The metal sheet is inserted between the rollers: depending on the distance and the curvature to which the calender rollers are set, objects of different shapes and thicknesses can be obtained. Shapes can range from cylinders to cones.
Metal spinning also called spin forming or metal turning is a manufacturing technique that allows to shape discs or tubes into an axially symmetric form by rotating it at high speed. Spinning can be performed by hand or by a CNC lathe.
There are many different welding techniques. The most common one is a high heat process which melts the base material with the addition of a filler material. The high heat creates a weld pool of molten material, that once is cooled off, forms a joint stronger than the parent metals. In Arc welding, the joint is created by using electricity, this creates enough heat to melt the metals only near the welding point. SMAW or stick welding, MIG welding and TIG welding all exemplify arc welding. Welding can be used to join brass, iron, stainless steel, aluminium.
When high quality and repetitive welding are necessary it’s possible to use a welding robot station. The robot sits on a welding table and is completely automated to perform both the weld and handling of the parts.
Patina is a thin layer of tarnish that forms on the surface of copper, brass and bronze as a result of oxidation or other chemical processes.
The artisans intuitive and expert hands manage the chemical process by soaking, rubbing and drying each individual piece.
The final colour is the result of a complex balance between chemicals and the time the metal has been exposed to them.
To achieve a good finish, the pieces need to be sanded. The process starts with a rough abrasive and each subsequent stage uses a finer one until the desired finish is achieved. The rough sanding removes imperfections on the metal surface, whilst the finer abrasives leave progressively finer lines invisible to the eye. Different degree of polishing can be performed on all metals: dull polish, satin polish, bright polish and the irresistible sparkle of a full mirror polish.
Varnishing offers infinite possibilities when choosing a finish, ranging from liquid metal to oxidation and power-coating.
Liquid metal is a process of cold metalization applied by spray, allowing to realise finishings with a metal effect on metal, wood, or mdf. When used on a modelled substrate can replicate the effect of metal casting.
An open flame applied directly on metal can achieve amazing colours and textures when used by the expert hand of a craftsman. The texture consists of ripples and ridges which are created by melting the metal surface and controlling the position and timing of the flame application. This process is very time consuming and requires great ability in controlling the amount of Oxygen and therefore the intensity of the torch flame.
The technique for making Damascus steel had been lost to the centuries, and only recently some makers have brought this process a new life.
The Damascus steel technique requires the craftsman to take several different alloys of steel and iron, forge or cast them together, and then work and fold that steel until it forms a desired patterned appearance.
Embossing, stamping, chasing, hammering and hand engraving are applied on malleable materials that can be shaped by the use of heath combined with tools and hammers of different sizes and shapes.
These techniques are very ancient and have been extensively used worldwide as they require very simple and inexpensive tools.
Etching is a technique that uses strong acid or mordant to cut into the metal surfaces.
By protecting parts of the metal surface is possible to create decorations and drawings incised in the object.