What Is Cast Iron Brazing?

Brazing is often used to repair cast-iron parts.

Cast-iron brazing is a process used to repair or join cast-iron parts. Unlike welding, the base material is not melted during the brazing the process. The brazing material coats the edges of each part and holds the parts together after it hardens.

Why Brazing?

Cast iron is notoriously difficult to weld. Brazing can provide a structurally sound repair or joint for most cast-iron parts and is far easier to perform than welding.

Brazing Methods

Brazing can be performed by hand using a torch or for some automated production methods, performed in a furnace.

Brazing Materials

For brazing cast iron, nickel is the most commonly used filler material.

Cooling

Cast-iron parts that have been joined by brazing must be cooled very slowly to avoid thermal cracking. Pack the part in sand, which acts as an insulator, and allow to cool for several hours or several days, depending on the size of the part.

Benefits

Brazing results in better overall tolerances because the base metal is not melted. Because brazing is performed at a cooler temperature than welding, there is less potential for cracking or warping of the base part.

References

• Brazing Cast Iron