On the side glass I was working on, I spent about 20 minutes of concentrated sanding on each spot with each sanding pad, so Id say over an hr and a half just with the discs starting from most coarse to finest. With the slurry, It took about 30 minutes to get both sides done as it went quicker. First I went left to right, overlapping my passes, then up and down, doing the same thing. The stuff is like toothpaste and it covers well.