Cast iron has been a go-to material for skillets, pans and other cook wear for centuries because of its affordability, durability and near ideal properties as a heat conductor. Although cast iron is durable, it can nonetheless suffer damage.
To avoid damage, never put the cast iron skillet in a dish washer and do not allow it to rust. After washing, make sure to completely dry the skillet.
Usually, damage can occur in two forms. Warping can occur from weight or pressure bending the cast iron, but it's more likely to occur over time as the uneven alloy of the cast iron succumbs to changes that occur during cooking. Cracking or breakage of a skillet is more serious as well as more common due to cast iron's uneven structure which allows for the formation of grains along which the cast iron material can fracture.
Either form of damage to a cast iron skillet will require welding, so it is inadvisable to attempt it unless you have previous welding experience.
- The first step is clean the area around the fracture. Any grime remaining on the cast iron surface once the welding is attempted will lower the purity of the resulting alloy, destabilizing it and promoting further breakage.
- To clean the skillet, seal the cast iron in an airtight area such as a garbage bag along with a cup of ammonia. Leave it inside the plastic bag for three to four days, and then scrub away the loosened grime for a complete chemical removal of buildup.
- The second step after cleaning the fractured area is to go about actually welding the fissure.
- If the damage is in the form of a crack or break: Start by drilling holes approximately 1/4 centimeter or 1/8 of an inch in diameter at the ends of the crack. Fire the cast iron to a temperature of at least 315 degrees C (600 F). Weld along the damage with a nickel alloy, and then gently work the metal with a hammer for a minute to stabilize it against further damage. Gently cool the skillet over several hours to avoid cracking from changing temperature.
- If the damage is in the form of a dent: Fire the cast iron around the metal to a temperature of at least 315 degrees C (600 F) or until malleable. Gently work the metal back into shape with a hammer. Gently cool the weld over several hours.