Procedure for Bronze Welding PDF Print E-mail

Procedure for Bronze Welding

by Cast Iron Weld & Repairs, Inc.


Preparation for bronze welding is made by grinding and removing all broken cast and cleaning parent metal with a rotary file, and shaping to a rounded V about 38 degrees to ¾ through the parent metal. The depth depends on whether the backside of the crack is open to welding. If it is, a cover-up weld is made on the backside.


The welding materials are: special flux, low temperature low fuming bronze, torch, and air peening hammers. The broken area is heated to a pre-determined temperature and the welding bronze is applied.

We bond in and weld out. Using a rosebud, heat the area to be prepared and the surrounding 12 inches on every side until the point of repair reaches approximately 525 degrees Fahrenheit. The casting 12 inches from the repair site is approximately 300 degrees Fahrenheit. Heat the place of repair to the bonding temperature of 1300 degrees. Apply low-fuming bronze until the broken area is filled.

Allow the casting to cool slowly while stress relieving the bronze every fifteen minutes. We peen the weld with air hammer to relieve bronze shrinkage and heat stress. The peening process is used several times while the casting is cooling, leaving weld in a dense, stress free condition.

The excess weld metal is ground down leaving the area smooth so the working stress in the normal operation of the casting will not be interrupted. The area is then dye checked and tested for leaks. The weld is stronger than the parent metal and is a permanent repair.

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