Question

Discuss Arc Welding and Gas Welding fixtures and some considerations when making them

Answer 1

1. Gas Welding Fixtures

In case of gas welding the heat loss from the weld area must be kept to a minimum as heat loss may result in development of cracks in the weld. To avoid this most of the fixture parts must be far away from the weld line. This can be achieved by keeping the contact area of the clamps and fixtures as small as possible. When welding materials like aluminum and copper, they could be excessive heat loss even with a minimum contact area. To prevent this, the fixture can be tack welded at points far away from the main weld line.

Some considerations for making a Gas welding fixture:

1. The fixture must b rigid to keep the work piece flat to prevent distortion
2. must have minimum contact area at points of fixing
3. fixture material must be heat resistant
4. fixture must retard the flow of heat

2. Arc welding fixture:

Unlike gas welding, arc welding involves more heat concentration along the weld line. As such, the fixture for arc welding must permit heat dissipation, as well as providing support and alignment to the parts being welded.

Some considerations for making a Arc welding fixture:

1. the fixture must provide the necessary force for proper alignment of parts without causing unnecessary strain
2. support must be provided by the use of backing bars which must be parallel to the weld lines
3. fixture must not hinder the accessibility to the weld area
4. backing bar must also be designed in a way to prevent distortion