In the OxyFuel backhand welding method, the torch precedes the welding rod, as shown in figure 11-5. The torch is held at approximately a 45 degree angle from the vertical away from the direction of welding, with the flame directed at the molten puddle. The welding rod is between the flame and the molten puddle. This position requires less transverse motion than is used in forehand welding.
Increased speeds and better control of the puddle are possible with oxyfuel backhand welding technique when metal 1/8 in. (3.2 mm) and thicker is welded, based on the study of speeds normally achieved with this technique and on greater ease of obtaining fusion at the weld root. Backhand welding may be used with a slightly reducing flame (slight acetylene feather) when desirable to melt a minimum amount of steel in making a joint. The increased carbon content obtained from this flame lowers the melting point of a thin layer of steel and increases welding speed. This technique increases speed of making pipe joints where the wall thickness is 1/4 to 5/16 in. (6.4 to 7.9 mm) and groove angle is less than normal. Backhand welding is sometimes used in surfacing operations.
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