First of all, when the cleared surface stain steel doors, using soft cloth wipe, is very easy to scratch the surface with a hard cloth. When the stain is too heavy, use neutral detergents, toothpaste or furniture cleaning agent, after going to the stain, then dry-erase (don't rinse). Note that soaked in neutral reagent or rag with water not on the surface of steel doors placed for a long time, otherwise it will damage surface immersed, discoloration or peeling of surface finishing materials. Steel-wood door edges and not excessive scrubbing, or it will cause edges and peeling paint.