Aluminum oxidizes quickly, forming a dull gray film, which ruins its beautiful finish. Usually, aluminum oxide is easily removed with natural solutions including vinegar and lemon. Be careful, however, when using abrasive cleaners to scrub them, as they can scratch the metal. There is another more serious problem associated with the oxidation of aluminum called poultice corrosion and which is most evident on painted parts of boats.
Steps
Method 1 of 3: Clean aluminum oxide from kitchen utensils

Step 1. Brush off dirt and dust with a soft bristle brush
Before treating the corrosion, first remove all the residue covering it. Use a non-abrasive detergent, such as regular dish soap.

Step 2. Boil the charred residue
If you want to remove burnt food residue from the bottom of a pan without damaging it, pour a little water into it. Then put it on the heat and let the liquid boil for about 10 minutes. After that, remove it and use a wooden spatula to remove the leftover food which should soften. Repeat this until your pan is clean.
Do not use steel wool or scouring pads to get rid of food scraps that have stuck on your aluminum pans, otherwise they could get scratched and future cleanings would be more difficult

Step 3. Boil some vinegar or lemon juice in the pot
To remove oxidized aluminum on a saucepan, mix inside water with vinegar or lemon. Then put it on the heat and let the solution boil for 15 minutes. If needed, you can add small aluminum utensils inside the large pot to process them at the same time. Repeat this if necessary.
The mixture should consist of approximately 30 ml (2 tablespoons) of vinegar or lemon juice per liter of water

Step 4. Rinse your pan
Then dry it. Try running hot water over your pot to remove any traces of vinegar or lemon juice. Wipe it off at the end with a cloth to dry it.
Method 2 of 3: Clean aluminum oxide from larger areas

Step 1. Clean the surface with a soft bristle brush
With your accessory, try to remove all large particles and dust.

Step 2. Scrub the surface with a sponge and dish soap
Wet the sponge and apply a little detergent before rubbing the metal with moderate pressure. Sometimes with this simple operation, you may be able to clean the oxidized aluminum.

Step 3. Try rubbing with lemon
If with soap you couldn't solve the problem, try this citrus fruit. Cut it in half and sprinkle salt over the exposed pulp. Use this exposed part to rub the aluminum so that the action of the acid juice and grains of salt dissolve the oxidized layer. Do not apply a lot of pressure, as salt is abrasive.
You can also apply lemon juice and salt to a cloth to gently clean the surface

Step 4. Switch to an aluminum cleaner in the most severe cases
If the oxidation layer is difficult to remove, apply such a product to No. 0000 or 000 steel wool. Wear gloves and rub the difficult spots as gently as possible.

Step 5. Rinse the aluminum with a clean sponge
Do not allow detergent, lemon or other products to dry on the surface. Use a damp sponge with water only to remove all traces of soap.
Method 3 of 3: Avoid poultice corrosion

Step 1. Watch out for cracks in the paint
Be aware that although it may seem unattractive, the coats of paint prevent the formation of aluminum oxide and prevent poultice corrosion. When the paint begins to crack on aluminum that is often exposed to water, corrosion develops and eats away at the material.
This type of oxidation occurs as a white powder or a viscous substance of the same color

Step 2. Remove paint chips
Scrape off the paint where it started to crack. Slide a putty knife under the paint to lift it.
If you need to treat large areas, use 220 grit sandpaper to sand the paint. Try to create a kind of gradual transition at the edges between the painted parts and those that are not

Step 3. Use a multipurpose stripper to remove the wax layer
Dampen a cloth with this product and rub the area you just scratched.

Step 4. Apply an epoxy paint
Find one that is almost the same color as the rest of the paint. With a brush, apply a few coats of paint to obtain a thick layer. You do not need to apply a primer if it is a small spot that you want to paint.

Step 5. Apply sealant to the hardware
Movable materials such as fasteners and lifting beams often damage the surrounding paint when in motion. So the paints in these areas usually don't last long. Then apply a polyurethane sealant having a low adhesive power or based on polysulfide around these elements. Apply the product all around the equipment so that the paint cannot seep in and reach the aluminum.