Step 4 · Cut and Remove the Damaged Section
Equip your reciprocating saw with a new diamond grit or carbide-tipped blade designed for cast iron. With a firm two-handed grip, start the saw and bring the blade into contact with the first marked line. Apply steady, firm pressure and let the saw do the work. The process will be slow and may create sparks. Once the first cut is complete, repeat the process on the second mark. Have a helper ready to support the weight of the section as you finish the second cut, then carefully lower it into the bucket. Be prepared for some residual water to spill out.