Chips are small, hard, randomly-shaped abrasive particles which will loosen scale and rust from tank walls, thereby augmenting the action of solvent chemicals to remove/suspend internal contamination. This material can be used in steel or aluminum tanks and with various adjunct solvents EXCEPT TANK ACID which will attack the chips and produce excessive gassing. Aluminum oxide has been successfully used for tank tumbling for 40 years. Use 25-35 lbs. per tank.