Step 8 · Cool and Clean
Allow the newly soldered joint to cool down naturally without being disturbed for several minutes. Do not try to accelerate cooling by quenching it with a wet rag or water. Rapid cooling can shock the metal, creating stress fractures in the joint that may lead to future leaks. Once the joint is cool enough to touch safely, use a damp rag to wipe away any remaining flux residue from the outside of the pipe and fitting. This step is important for aesthetics and also because leftover flux is acidic and can cause the copper to corrode over time, potentially weakening the pipe.