8 in. Blue Steel Blade Taping Knife

A:  Yes, all blue steel taping knives will rust. The blades have a protective coating on them when purchased. As they are used the coating is worn away exposing the blue steel. Blue steel is used because it is more flexible than stainless steel giving a better finish result. After using the taping knife simply wash the knife with water to remove drywall mud. Thoroughly dry the blade to prevent formation of rust. If available give the blade a spray of WD-40 to prevent rust until the next use. As a side note; if the blade does rust it does not harm the wall surface or negatively impact the wall.