In some cases defective castings may be remedied.

(1) Strains are removed from castings by annealing. This is usually necessary only with steel castings, or chilled cast-iron castings.

(2) A warped casting may be straightened by weighting it and building a charcoal fire under it to heat it red hot. Provision must be made not to let the weight bend the casting more than is needed.

(3) A small hole caused by sponginess may be drilled out and plugged. A small blow hole or small collection of blow holes may frequently be remedied in the same way.

(4) Cracked or broken castings may in many cases be repaired by "burning on" by electric welding, or brazing.

The Steel Foundry.