Before you start welding you will want to preheat the aluminum to help the panel get up to a similar temperature as we’re welding. On thin gauge aluminum like this you will only need to pass the flame over the weld seam for a short time before beginning to weld. Start by aiming your flame at the center of the seam and as soon as you begin to see the metal get shiny at the very center of the seam you will want to begin dipping your filler rod. Once you get a puddle going you will want to move quickly and continue to feed rod into the “keyhole” you may see. The rod should flow into the seam with easy and lay flat. If the rod is just piling up on the surface you need to slow your travel speed down, add less filler rod, or get your flame closer to the surface to raise the welding temperature. Continue to dip in and dip out like we’re TIG welding.