5.4 GAS WELDING

• Basically, filler and base materials are heated to the point of melting by a burning a gas.

• Two common types are,

- oxygen-acetylene

- mapp gas

• These are suited to a few applications, but they produce by-products that can contaminate the final weld.

• Typically the flame is adjusted to give a clean burn, and this is applied to the point of the weld.

• A welding rod will be fed in separately to melt and join the weld line.

• Flux can be used to clean the welds.

• Process variables include,

- gas and oxygen flow rates

- distance from surface

- speed

- material types

- surface preparation of materials