Step 5 · Solder the Joints
Place the fire-resistant cloth behind the work area to shield walls and other materials from the flame. Put on your safety glasses and gloves. Light the propane torch and begin heating one of the T-fitting joints. Heat the fitting, not the pipe itself, moving the flame constantly to distribute heat evenly. When the flux begins to bubble and smoke, touch the tip of the lead-free solder to the joint seam, opposite the flame. The hot fitting will melt the solder and capillary action will draw it into the joint, creating a complete, silver ring. Remove the solder and then the flame. Let the joint cool without disturbing it. Repeat this process for all three joints on the T-fitting and the cap on the air chamber.