Place the hardware into your bucket of warm water/vinegar/soap solution and leave it there for 30 minutes or so. Then take out, rinse with clean warm water and then dry. This should loosen any dirt and can be used on a variety of hardware, such as door hinges, escutcheons, and letterboxes.
Dampen the soft cloth in the warm soapy water and rub over the handle, going from side to side and top to bottom. Take your dry cloth and dry the handle from top to bottom to avoid any streaks. To maintain the gloss of your handle, apply a thin layer of wax or polish using another cloth.
If you encounter tarnished brass, create a paste using equal parts of lemon juice and baking soda. Apply this mixture to the brass door handles and let it sit for a few minutes before wiping it off with a damp cloth. Rinse with clean water and dry with a soft cloth to restore the shine.
Place the doorknob in the laundry tub and sprinkle some fine salt on its surface. Get the green scourer and put some cleaning vinegar on it and start scrubbing the surface. Keep adding the solution for stubborn spots. Rinse in clean water once the doorknob has regained its finish.
Applying vinegar to rust dissolves the oxide and leaves behind a water-soluble salt that you can remove easily. It is called neutralisation, and this reaction happens between rust and acetic acid, which is why cleaning vinegar helps remove iron oxides from household surfaces and objects.
With the hardware fully wet, sprinkle on a powdered cleaning product so the metal is completely covered. If you are using vinegar and baking soda, first brush the hardware with a layer of vinegar, then sprinkle on baking soda. When it starts to fizz, you will know it is working.
For Heavy Tarnish:
Opt for a paste of baking soda and lemon juice or vinegar and flour. Let it sit for 30–60 minutes before rinsing and polishing.
The best bet, once chrome has been washed with soapy water and dried, is to use a metal polish or chrome cleaner to get rid of any pitting or discolouration. A cheaper option, though, is to use some kitchen tin foil and a light oil or polish instead.
Aluminum is the common material used for foiling the door knobs. But why wrap door knobs in foil? It proves to be good for enhanced security and blockage of the static electricity from the doorknobs to the human body.
Scrub: Using a polishing agent (my favorites are Barkeeper's Friend or Brasso) and 0000-grade steel wool gently polish the tarnish and grime off of the hardware. A toothbrush is also helpful for getting into the nooks and crannies. Polish: Take a soft cloth or rag, and use it to dry and polish the hardware.
ADCA president Paul Woodfin says that a 19th century doorknob can sell for anywhere from $20 to hundreds of dollars. If you have a high-quality antique bronze doorknob in good condition, you may be in luck — Woodfin claims these can net you a payday of over $1,000.
Soak your cabinet hardware in a bucket of warm water, vinegar, and a little mild dish soap for 30 to 60 minutes. Then remove, wipe, and rinse with warm water. Use a soft toothbrush to remove any stubborn grime. This works great for dirty hinges, too.
Vinegar can dull brass if left on the surface for too long or if the brass is scrubbed too hard with vinegar. Use vinegar sparingly when cleaning brass, and always use it mixed with water or other products to minimize the abrasiveness.
Flour/Vinegar Paste: Mix one teaspoon of salt into a 1/2 cup of vinegar. Add flour until the liquid becomes a paste and spread over the brass. Let the mixture sit for up an hour then rinse and buff the piece.
The surface roughness is increased in the presence of H2O2 compared to the untreated brass. This increase in surface roughness is characteristic of dezincification of brass or dealloying in other alloys [3]. The increase in surface roughness becomes more pronounced with the increase of H2O2 concentration.
Clean Oxidised Door Handles - In Summary
To effectively clean and maintain the shine of your door handles, use material-specific solutions such as lemon juice and baking soda for brass, soap and water for chrome, and white vinegar and olive oil for stainless steel.
Mix 1/4 salt (cup, TBSP, tsp, etc.), 1/4 (cup, TBSP, tsp, etc.) flour, and enough vinegar to make a thick paste. Use a soft cloth (I use microfiber.) to rub the paste on the surface of the copper. Buff until the oxidation is removed.
For a regular cleaning that you might perform weekly, Cohoon suggests mixing warm water with vinegar in a spray bottle and spraying knobs with the mixture. From there, wipe away the grime and excess solution with a microfiber or soft cloth.
First, remove dust or debris from the surface with a soft cloth or brush attachment to a vacuum cleaner. Then, use warm water with a mild detergent or soap to create suds. Gently scrub the knob using these suds and rinse off with clear water.
One nontoxic method is to fill an aluminum pan with hot water, salt and baking soda, stir until it is all dissolved, and then soak the pieces until a chemical reaction occurs that removes the tarnish. This technique is faster than hand cleaning but may cause pitting and remove the more desirable tarnish called patina.