Page 256 of 561

BRONZE 264

Unitor Bronze 264 is used to braze welding steel, cast iron, malleable cast iron, copper and brass with high copper content (red bronze) and also for welding brass and bronze. Use silver solder AG 60-252 for Yorcalbro and Cunifer.

Cast iron joint surfaces must be clean and bright (i.e. cleaned off with grinder). Graphite should be removed with a sharp tool or by means of chemicals. Clean off burr, round off sharp edges.

The use of bronze rod for joint brazing has become widespread as brazing is easier than ordinary welding and requires less heat. Brazing provides a tough, strong joint.

Bronze brazing requires thorough cleaning of the joint surfaces, good mating of the parts and correct working temperature.

Remove inside burr.

Choice of welding neck will depend on the thickness and size of the workpiece. Do not use too large a welding neck, or you may overheat the joint. The flame should be adjusted with a slight excess of oxygen (oxidising).

Apply Unitor Bronze Flux 261 PF paste to the rod and joint edges. Check the temperature by melting off a drop from the rod on the joint surface and move the torch in a circle around the drop until it melts and flows outwards. Repeat this process to form a continuous bead. Braze with Leftward technique.

Flux is corrosive, so any surplus after brazing should be cleaned off with hot water.

3.05 Bronze Flux 261 PF.

Melt of a drop.

Move the torch in a circle until the drop melts and flows outwards.

255