5.10 Weld-Cleaning Equipment
It is very important that the base metals in weldments be cleaned prior to welding. It is difficult to weld dirty or corroded surfaces. If this is attempted, the resulting welds will normally be of poor quality. Many types of equipment and tools have been developed to clean joints and welds. Cleaning may be done by using sandblasting machinery, rotary wire wheels, and tools such as chipping chisels, hammers, and wire brushes. Nonferrous metals may be chemically cleaned, especially in production welding situations. The amount and size of the welding done usually determines the kind of cleaning apparatus needed.
The slag that covers each weld bead must be removed before the next weld bead is laid, to prevent inclusions in the finished weld. The slag on the final bead must also be removed before the weld can be inspected or painted. This slag coating may be removed by a rotary wire wheel, or by tapping the slag with a pointed hammer, called a chipping hammer. In either case, suitable eye protection must be worn.
Chipping hammers are often double-ended, as shown in Figure 5-52. One end is shaped like a chisel for general chipping. The other end is shaped like a pick, for reaching into corners and narrow spaces. Another type of chipping hammer is shown in Figure 5-53.
The slag that covers each weld bead must be removed before the next weld bead is laid, to prevent inclusions in the finished weld. The slag on the final bead must also be removed before the weld can be inspected or painted. This slag coating may be removed by a rotary wire wheel, or by tapping the slag with a pointed hammer, called a chipping hammer. In either case, suitable eye protection must be worn.
Chipping hammers are often double-ended, as shown in Figure 5-52. One end is shaped like a chisel for general chipping. The other end is shaped like a pick, for reaching into corners and narrow spaces. Another type of chipping hammer is shown in Figure 5-53.
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