AL7075 is a lightweight, strong aluminum alloy that is extremely sensitive to weld cracking. Most literature treats this alloy to be unweldable and advises against fusion welding it at any cost, while many other groups claim to produce quality welds in their everyday designs. Although research has been done on this alloy in the past, there still seems to be a void in the knowledge of what procedures can be used to weld it and which can not. The effects of filler metal dilution on the microstructure and mechanical properties of AL7075-T6 aluminum sheet were studied. Using 1/8-inch alclad AL7075 sheet and ER5356 filler, full penetration welds were made on workpieces with various included joint angles using an automated GTAW system. Testing was done in the as-welded, naturally aged, and post weld heat-treated conditions. The results show that by using a cracking resistant filler and by selecting the proper dilution ratios and PWHT, strong, dependable welds can be produced on thin Al7075 sheet.