A Metal spray gun is used for the thermal coating process which uses a single wire, cord, and powder for coating. This feed material is melted in an oxygen fuel gas flame or with the help of an electric arc. This molten metal is atomized by compressed air and impinges on the surface of the substrate.
For melting the coating material both flame and electric arc process is used. The electric arc process of a metal spray gun, the arc is generated between the cathode and anode. In metalizing gun coating material having opposite polarity is used.
In the electric arc process, two methods are used to forward the coating wire. One is an air drive and the other is electric arc drive. The air drive, compressed air is used to forward the wire and in electric drive, a motor is used to forward the wire which connected to the electric panel.
In the flame type compressed air is used with oxygen and acetylene gas to melting the coating material. Thermal spray gun LPG gas is also used sometimes at the place of acetylene with oxygen.
1. The gas head valve controls the flow of gases and air both the gas head and the drive turbine.
2. The speed control rings adjust the rate of wire feed.
3. The wire valve thumb-slide (trigger) causes the drive rolls to grip or release the wire.