What should be done to the door track before the doors are hung?

Before hanging the doors on an elevator, it is essential to sand the door track. Sanding the door track helps to smooth out any irregularities or rough surfaces that could interfere with the proper operation of the door. A well-prepared surface ensures that the doors can glide smoothly along the track without binding or jamming, which is critical for both functionality and safety.

Sanding also helps to remove any oxidation or debris that may have accumulated on the track since it was manufactured or installed. By ensuring that the door track is smooth and free from imperfections, you help guarantee that the doors can open and close effectively and that they will seal properly when shut, contributing to the overall efficiency of the elevator system.

The other options, while they all might seem like reasonable considerations in different contexts, do not address the immediate need for preparing the door track prior to installation. Painting, sealing, or aligning may become necessary later in the process but do not provide the initial preparation required for optimal door operation.