Kitchen sink
Usually stainless steel, and the surface in a house most exposed to the two things that damage stainless steel: chlorides and abrasion.
Precautions
- Rinse thoroughly afterwards
- Never mix with other cleaning products
Start here
What this is, what tends to go wrong with it, and what to do about it.
Made from
Which part are you cleaning?
These parts take different answers. Cleaning one the way you clean another is a common way to damage this.
- Sink waste
Where the smell actually comes from, and the place two drain products from opposite families can meet each other out of sight.
Household plastics, Chrome plating
Things not to use here
What tends to go wrong
What hard water leaves behind when it evaporates instead of being wiped away. A mineral film, not dirt, and the fix is at the drying stage.
Why it is difficult: Water hardness, Evaporative deposition
A hard, chalky calcium carbonate deposit left by hard water. Dissolved by acids, essentially untouched by detergents.
Why it is difficult: Water hardness, Crystallisation, Adhesion and cohesion
- Fingerprintsvia its material
Skin oils transferred by touch. A greasy soil rather than a dirty one, which is why water alone does not shift them and why they return immediately.
Why it is difficult: Surfactancy
- Rustvia its material
Hydrated iron oxide from corroding iron or steel. Distinguish a surface deposit, which cleans off, from active corrosion of the item itself, which does not.
Why it is difficult: Corrosion and passivation, Why old stains are harder, Adhesion and cohesion
- Burnt-on food and carbon depositsvia its material
Food heated until it carbonised and bonded to the surface. Time and softening do the work; scouring powder does the damage.
Why it is difficult: Contact time, Carbonisation, Adhesion and cohesion, Why old stains are harder
- Greasevia its material
Fats and oils, which water alone cannot lift. Removed by surfactants, by heat, by solvents, or by alkalis that convert the fat into soap.
Why it is difficult: Why oil resists water, Emulsification
- Heat tintvia its material
The rainbow or brown bloom on stainless steel that has been heated. Not a deposit and not dirt: the metal's own surface oxide, thickened by heat.
- Mouldvia its component
A living growth, not a stain. Killing it and removing the staining are two separate jobs, and neither addresses the moisture that caused it.
Why it is difficult: Porous and non-porous surfaces, Moisture control and recurrence, Cleaning, sanitising and disinfecting, Organic load, Surface roughness
The science behind this: Corrosion and passivation, Water hardness, Chloride attack, Cleanability is designed in
In detail
A stainless steel sink concentrates almost every hazard the material has. Salt from cooking water, bleach used to freshen a drain, and dishwasher tablets dissolved in a bowl all put chloride in prolonged contact with the passive layer, which is the specific condition that produces pitting corrosion rather than the general dirt a sink looks like it has. The trade association's guidance is unusually direct about the domestic case: soaking stainless sinks or cookware in dilute bleach solutions for long periods, overnight for instance, is stated to be inadvisable, and surfaces should be washed after food preparation because salt residues cause pitting over time. Abrasion is the other half. A sink is where scouring pads live, and wire wool leaves particles of ordinary carbon steel embedded in the surface which then rust — producing what looks like a stainless sink rusting and is actually a contaminant corroding on it. Sinks also accumulate hard-water marking faster than most surfaces, for the ordinary reason that they are wet several times a day and usually left to dry themselves.
Related
- Kitchen sink has the component Sink waste
- Kitchen sink is made from Stainless steel
- Kitchen sink is commonly affected by Water marks
- Kitchen sink is commonly affected by Limescale
Hacks and claims involving this
- Steel wool for stubborn marks on stainless steel Does not work
- Leaving bleach in the sink overnight Does not work
- Drying a surface prevents water marks Supported
- Washing soda as a general-purpose cleaner Disputed
Sources for this page
Sources
Cleaning methods for stainless steel
British Stainless Steel Association · Trade or professional body
Relied on for: That soaking stainless steel sinks or cookware in dilute bleach for long periods is not advisable, and that salt and concentrated salt and vinegar mixtures may cause pitting over time. (states this directly)