Braze Welding of Cast Iron - Castings may be preheated to about 450ºC. A manganese bronze filler rod should be used with the bronze flux. To achieve good mechanical properties a nickel bronze rod may be used. Edges should be bevelled to 90"Vee. A short shoulder in the root of the Vee if provided helps preserve alignment. A blow pipe usually two sizes smaller than used for steel of the same thickness is used. The flame is neutral or slightly oxidizing. The leftward method is used with the blowpipe describing a regular semicircular movement throughout the entire welding. The blowpipe angle is 6070°C. If the job can be arranged to weld uphill 307ff' to the horizontal, better results are obtained.
