When your windows and doors are old, do you want to replace them directly or continue to use them? What on earth can old aluminum windows and doors do? 1. Renovation of aluminum windows and doors. The methods commonly used in the renovation of aluminum alloy windows and doors are as follows: 1) No. 600 sandpaper is polished with soap water, and then self-sprayed varnish is used. 2) Angle grinder with steel wire wheel (fine wire) electric removal. 3) it is time-consuming and laborious to scru......