Step 4 · Clean, Flux, and Dry-Fit Components
Thoroughly clean the outside of the two cut pipe ends and the inside of all three openings of the copper T-fitting using emery cloth. The copper should be shiny. Also, clean one end of your 12-inch pipe section and the inside of the copper cap. Once clean, use a flux brush to apply a thin, even layer of soldering flux to all cleaned surfaces. Assemble the pieces for a 'dry fit': slide the T-fitting onto the pipe ends and insert the 12-inch air chamber pipe into the top of the 'T'. Place the cap on the air chamber pipe. Ensure everything fits snugly and is aligned correctly.