If a blade of the propeller is bent or part of the blade is damaged, then the balance of propeller will not be equal. This will put the propeller shaft and the stern seal under abnormal stresses and may cause more damage to the system. The efficiency of the Vessels will also decrease. Because the propeller is made of an Iron and Bronze alloy, underwater welding can not be performed to repair the damage.

As a temporary repair, the damaged area must be removed and the end profiled to obtain a uniform finish. To balance the blade, an equal amount of material must be removed from the opposite blade. To achieve this, accurate measurements of the damaged area must be taken.