Do this in the least seen section of the window.
Drilling holes in window frames.
Take a twist bit slightly larger in diameter than the hole you just drilled and gently hand twist it over the top of the hole.
You can buy fancy deburring tools to smooth sharp edges but before spending money on one try this trick.
Drilling holes in the double pane glass is the first step to removing the condensation by allowing air to access the area.
Small holes in a wooden window frame are repaired easily with wood filler or putty.
Position a stepladder near one side of the window.
Cut them a tad longer than that measurement and place them into both corners of that space.
Step 2 drill a hole in the diagonally opposite corner of both the interior and exterior panes of the window.
Place a curtain rod bracket at the desired location at one end of the window frame.
Drill a hole in the interior and exterior panes of the window using the drill and glass drill bit.
What i do is cut two 1 inch dowels or whatever small wood you have and fit it to the top of the window between the frame and the top of the window that is holding the ac.
If the pulled down window is holding the ac in i would not drill holes in the frame.
After drilling a hole in metal it s a good idea to remove any sharp edges or burrs left behind.