Getting real close to being finished with the tank. I saw somewhere online a guy saying it takes 6 hours to sand down a tank. I guess that's assuming there's no deep scratches. I've got around 20 hours into mine so far. He also said don't use power tools too, but I used a Dremmel on it's lowest speed with a sanding wheel to dig down to virgin plastic. Then I used a vibrating electric sander with 120 applying light preasure. You also have to move to another spot and let it cool as you go. Hand sanding only started after it was roughed out flat. It may seem like a lot of trouble, but good luck finding one of these early plastic tank in nice condition.