The T6 heat treatment of aluminum extrusion profiles containing charge weld zones presents unique challenges, as solution temperature governs both the solute dissolution efficiency and the thermal stability of the weld interface. This study systematically investigates the influence of solid solution temperature (500°C, 530°C, and 560°C, each for 6 h) within a T6 cycle on the mechanical properties, microstructural evolution, and electrochemical corrosion behavior of extruded AA6061 hollow panels, considering both panels without and with charge weld joints. Macrostructural and microstructural analyses, Vickers hardness profiling, uniaxial tensile testing, three-point bending, and potentiodynamic polarization tests in 3.5 wt.% NaCl solution were performed on skin and fin regions of all specimen groups. Solution treatment at 560°C induced severe blistering and surface cracking attributed to entrapped hydrogen expansion under diminished hot strength, rendering those specimens structurally compromised. A solution temperature of 500°C was identified as optimal, yielding the most favorable combination of grain refinement, precipitate homogeneity, hardness, tensile strength, and corrosion resistance in base-material panels. Relative to the as-extruded condition, T6 treatment at 500°C increased Vickers hardness from 90-91 HVN to131-136 HVN, ultimate tensile strength from 303-318 MPa to 378-440 MPa, bending strength from 238-421 MPa to 318-489 MPa, and reduced the corrosion rate from 0.037-0.10 mm/y to 0.009-0.019 mm/y. Application of the T500 condition to charge-welded panels demonstrated that T6 heat treatment substantially recovered weld-zone hardness and tensile performance toward base-material levels, while also improving corrosion resistance relative to the as-extruded weld condition. Tensile strength of the weld region increased from 266-283 MPa to 380-387 MPa, bending strength from 127.5-276 MPa to 176-370 MPa, and corrosion rate decreased from 0.54-0.77 mm/y to 0.37-0.66 mm/y. These findings establish quantitative process-structure-property relationships for T6-treated AA6061 hollow extrusion panels and provide practical guidance for optimizing solution treatment parameters in lightweight structural applications that incorporate charge weld joints.