For light scratches, a little Flitz Polish on a microfiber with some gentle rubbing will generally do the trick. Just make sure to use as little polish as possible and remove any remaining polish with a soft cloth.
Many people who don't know how to make aluminum shine without polishing it will use WD-40, a Scotch-Brite pad, and some elbow grease to achieve a brushed look. The result is a bit more hazy and gray than you'd find with something that's been polished to look like chrome.
Rather than fixing the original scratch, use of any abrasives (including mechanical polishing) will only cause further damage to the anodized finish. There is no way to restore an anodized finish other than by completely removing the coating and re-anodizing the whole case.
Anodized Aluminum – Just Say No
Removing regular anodizing requires the use of dangerous caustic chemicals, while removing “hard anodizing” actually requires sanding off the coating to get down to the bare metal. Again, in most cases, it really isn't worth it.
Simply combine equal parts water and white vinegar in a spray bottle and apply the mixture to the aluminum surface. Then use a soft cloth to wipe the surface clean. To increase the shine, you can also use a fine grain steel wool buffing pad to smooth the surface even further.
Sanding. If you have a plain aluminium window frame that does not feature a special surface or texture, then sandpaper might be able to solve your problem. You should take care, though, and be sure to use the finest sandpaper that you have so that you don't damage your window frame further.
Depending upon the thickness of the metal, and the depth of the scratches, you can buff them out using VERY fine sandpaper, followed by emery cloth, followed by a soft cloth with a bit of abrasive powder such as aluminum oxide 1200 grit or finer.
Vinegar is an effective resource to clean aluminum. Mix one part white vinegar with one part water to create an acidic solution. The solution can then be used in different ways depending on the object being cleaned. To clean and shine an exterior, dip a cloth into the mixture and scrub the object clean.
Here are some additional tips that can be helpful when cleaning aluminum. You shouldn't use baking soda or an alkali-based cleaner on aluminum. These cause discoloration of the metal.
This is the most famous "trick", used to clean scratches on metal, as well as glass. Wet a clean cloth, on which you place a little toothpaste. Dab the scratches in the grain direction, and let it dry. Rinse with clean water before drying thoroughly with a soft, microfiber cloth.
Squeeze a small drop of metal polish onto a microfiber cloth. Scrub the metal polish into the affected area and the surrounding aluminum surfaces using back and forth motions and going with the grain of the aluminum. Keep rubbing until the polish disappears into the metal and the surface looks nice and shiny.
Toothpaste. You don't need a toothbrush for removing scratches from glass, but a small dab of toothpaste may help. Use the non-gel white kind. One that contains baking soda would be best.
As a material, aluminium has properties that make it very scratch-resistant for use in gates. Pure aluminium is soft and prone to scratching and denting easily. But garden gates are made from aluminium alloys which have blended the metal with others like magnesium, silicon, and zinc to make it much stronger.
If they are very fine surface scratches you can try automotive fine polishing compound and wax. Be careful. Regular clear and color anodizing is only . 0005 inches thick in the coating(one half thousandths).
While cleaning aluminium is a relatively straightforward task, there are some things to be aware of before you get started, and certain substances to steer clear of. Avoid alkaline cleaners such as ammonia – these chemicals can damage the surface of aluminium products, causing discolouration.
Aluminium is a reactive metal, reacting easily with acids and alkalis. Thus, acetic acid will dissolve it. Therefore, it is not recommended to store vinegar dishes in aluminium containers.
Apply a small amount of aluminum polish to the surface of your metal. Then, with a clean paper towel or cloth, wipe the surface using small, circular motions. After you remove the polishing residue, use another clean paper towel or cloth to buff the surface. When you do, use the same small, circular motions as before.
One of the most common ways to polish aluminum is by using a metal polish. This type of polish is readily available in most hardware stores and is relatively easy to use. Simply apply the polish to the aluminum surface and rub it in with a soft cloth.
If the anodic coating is damaged this will have a negative impact on any color anodizing. As a general rule, mild soap, alcohol, and acetone can be used to clean the surface.
Use an abrasive cleaning technique with a gentle soap. An abrasive cleaning sponge with mild dish washing liquid can work well. Do not use harsh acidic or alkaline cleansers because they may destroy the finish. Use solvents with care as they may stain the finish.