The stainless-steel sink surface has a resistance to hold water and, for this reason, can appear some "water ponds", simply eliminable with an absorbent cloth. This particularity is due to the water viscosity, to its chemical composition and to the sink finishing: situation that is more accentuated during the first life months of the sink. The water is withheld for the cohesion between the two elements. To verify this case, it’s enough to observe, for example, as the water drops are withheld even in a vertical wall, like a mirror a glass. It is important to pay attention also to the quality of water, not only for the quantity of limestone but, also for the percentage of iron that, when high, may cause dark marks similar to rust.
It's always necessary to keep in mind that eventual reddish spots, or other spots, improperly named rust, are due only to the degradation or to the oxidation of external material to the sink itself. Sometimes, also foods can mark the steel (lemon, for example). Therefore, not leave acidic foods, or with a high percentage of salt, in contact with the sink for a long time. Kitchen salt too, if it is laid on the steel for a long time (also one week) creates some halos, up to arrive, in extreme cases, to corrosion. This is due when cleaning is neglected.
Just a few important measures will ensure that a stainless steel sink remains unchanged over time: