Arc Spray Equipment
Arc spray (sometimes referred to as twin wire arc spray) is a process that uses an electric arc to melt wires.
The molten metal is then atomised with compressed air to create a spray stream that applies the coating onto the surface being sprayed.
Anti-corrosion or engineering coatings can be applied by arc spray and changing between the two is quite simple.
Arc spray systems are commonly considered to be easy to operate and also to automate.
Metallisation have a full range of arc spray systems for hand-held and fully automatic / robotic applications.
FAQs About Arc Spray
The process where by two wires (hence a common term for the process is Twin Wire Arc Spray), are fed into the pistol and electrically charged, one positive and one negative.
The wires are forced together and form an electric arc, melting the wire. Compressed air, passing through a nozzle, atomises the molten metal and sprays it onto the workpiece. There are three methods of wire feeding, push, pull and push/pull. The higher the current rating of the system, e.g. 350A, 700A etc., the higher the spray rate.
High deposition rates and easy to use equipment make arc spraying an attractive thermal spray solution.
On a typical handheld arc spray pistol, there is a trigger to start the wire feed. The head is held around 150mm from the substrate and moved sideways to deposit a consistent coating thickness in a similar way to paint spraying.
Different Personal Protective Equipment to paint spray is needed for the arc spray process as UV light and metal fume are produced.
Spray transfer MIG (or MAG) welding uses a larger standoff distance and the filler material is transferred as a fine mist into the weld pool. As with most welding applications, the heat affected one is more liable to corrosion and thermal spray can be used to protect against this.
Arc spray is typically used with compressed air as the atomising gas; this is the most economical option but (typically) gives a small amount of oxide in the coating. If the feedstock is very reactive or the oxide levels need to be kept to an absolute minimum an inert (usually nitrogen or argon) atomising gas may be used or occasionally a completely inert chamber.
This is typically made up of a power supply, power cables and hoses to the spray head, a spray head and a twin wire drive system.
The process where by two wires (hence a common term for the process is Twin Wire Arc Spray), are fed into the pistol and electrically charged, one positive and one negative. The wires are forced together and form an electric arc, melting the wire.
Plasma arc spray coatings (plasma spray) are made by introducing the feedstock into a gas stream heated by an arc between two non-consumable electrodes. Power level, gas flow and gas mixture can be adjusted to control the particle temperature and velocity.
Anti-spatter spray is a product that reduces the amount of weld spatter that sticks to a surface.
Zinc is a common arc spray material for anti-corrosion and other purposes. A thermally sprayed zinc coating offers sacrificial protection to the substrate; it offers good service life in non-acidic environments below 60⁰C and can be supplemented with sealers and paints. Metallisation offers a full range of zinc wire in all sizes.