Method for repairing a metal casting having a crack or break therein

Abstract

A metal lock system is provided for securing a crack or break in a metal casting from further cracking, breaking, or leakage. The metal lock system includes a metal lock having parallel, flat top and bottom surfaces and a plurality of alternating large and small lobes, and a plurality of tapered lacing plugs. The metal lock is imbedded into an irregular recess of precision drilled bores disposed adjacently in intersecting alignment. This binds the crack or break from further separation while the crack or break is sealed by imbedding tapered lacing plugs into lacing bores which are drilled along the crack. The preferred lacing plug has a tapered shaft, straight threads, a shoulder, and a break-off groove. the preferred tapered lacing plug threads into lacing bores with straight threads and the shoulder seats the lacing plug by crushing the first few threads of the lacing bore. The head of the lacing plug breaks off at the break-off groove at a predetermined torque. Another embodiment of the metal lock system is used when precision drilling is not possible. With this embodiment, the metal lock is a bar having spaced grooves on opposite longitudinal sides. The metal lock is imbedded into an irregular recess carved from the casting which lies across the crack and securing plugs are disposed within the grooves to hold the lock in position.