Step 5 · Assemble the Joint
Immediately after applying the flux, push the copper pipe into the copper fitting until it bottoms out and is fully seated. Give the pipe a slight twist, about a quarter turn, as you push it in. This action ensures that the flux is spread evenly across both surfaces, creating a complete seal for the solder to follow. Use a clean rag to wipe away any excess flux that squeezes out of the joint.