How to remove anodizing from aluminum

12 aluminum cleaning products, how and with what to clean aluminum

Aluminum is a fairly light and durable metal, and therefore is often used in the kitchen as the main material from which cookware is made. When plaque appears, it becomes unpleasant to cook in it, and it is impossible for safety reasons, and therefore the question arises of how to clean aluminum until it shines.

Cleaning features, general recommendations

Heating of aluminum cookware occurs evenly and does not require much time. After some time, carbon deposits begin to appear on aluminum cookware and traces of oxide become noticeable. Most often, they try to clean aluminum using dishwashing detergent, but it can only remove external dirt and grease.

Dishes made from this material should only be washed cold, since they can easily be damaged when hot. If a hot metal is immersed in cold water, it will become deformed, and therefore you should try to avoid such a failure.

You should not try to clean burnt food immediately using iron sponges and other objects. To make the task easier, you just need to pour warm water and wait about half an hour. During this time, the food will get wet and can be removed using a regular dishwashing sponge.

It is not recommended to wash aluminum cookware in the dishwasher, since the dishwasher uses hot water during the washing process, which can damage the material. To avoid deformation, it is recommended to wash aluminum cookware by hand with warm water.

You should not use strong acids in the process, as they will not be able to restore the shine of the dishes, and may harm them. It is also not recommended to clean it with metal sponges, which leave scratches on the dishes.

Cleaning aluminum cookware

The main disadvantage of aluminum is its softness. It is very easy to damage and also leave scratches on it. Even with frequent washing with a melamine sponge, the surface will soon begin to become matte, as a large number of micro-scratches will remain on it.

1. To restore shine, you need to use borax, ammonia and GOI paste. The latter needs to thoroughly rub the aluminum, and then, using a rag soaked in solvent, thoroughly rub the cutlery.
2. Aluminum cookware can be cleaned with such products as soap, ammonia, table vinegar and table salt.
3. Soot, oxide and other contaminants that accumulate on aluminum cookware can be easily removed using soft foam sponges or polymer bristles, microfiber or cotton cloths, and rags. It is necessary to ensure that they do not contain rougher and harder materials that can leave scratches.
4. A good aluminum cleaner is a special product designed for cleaning glass or porcelain. They do an excellent job, gently removing dirt and adding shine to the dishes.

Remove carbon deposits

Cleaning oxides and carbon deposits is also quite simple. This will require funds and products that many people have in their homes. Moreover, such cleaning does not take much time and does not require serious effort.

1. Aluminum is clarified using brine from cucumbers, fermented milk products such as milk and kefir. It is necessary to pour the available product into the dishes that need to be cleaned for half a day. Most often they leave it overnight so that you can simply wash the dishes in the morning. If you need to clean some objects from carbon deposits, they can be placed at the bottom of the container that was filled. Cleansing occurs thanks to the acids found in these products.
2. A sour apple will help clear carbon deposits and remove oxidation. The fruit needs to be cut in half and rubbed onto the desired surface until shiny. The acid will corrode all dirt, and therefore, after rinsing with water, the item will shine.
3. Contaminants can be removed using a saline solution. You need to take salt and water in equal proportions, and the first ingredient should be completely dissolved. Using a sponge, you need to apply the solution to the item that requires cleaning, leave it in this state for a while, and then rinse thoroughly with water.

Remove corrosion and oxide

Cleaning aluminum objects - a flask, dishes, coins - is quite simple if you know the easiest methods to do it. It is recommended to use traditional methods rather than standard dishwashing detergents, which will not cope with heavy stains.

Cream of tartar

You can remove blackness from aluminum using cream of tartar. Cleaning aluminum from oxide and corrosion with this product is quite simple: you just need to pour hot water into a bowl, dissolve the stone in it and add a small amount of citric acid. You need to bring the resulting solution to a boil, let it cool and wipe all the walls with a soft cloth.

We also recommend reading: How to remove the smell of burning in an apartment

Cream of tartar can be diluted with water to form a paste that can be rubbed onto dishes like a cleaning powder. This will help restore the shine to the material.

Table vinegar

Using 9% table vinegar, aluminum can be easily cleaned. This method is usually used for coins, but will actually clean more than just coins. If we are talking about dishes, then you just need to pour the solution into it and bring to a boil. Then let it cool and wash the item. If you need to clean other things, they should be boiled in this solution and then washed.

Soap solution

A soap solution helps get rid of light stains, but will not help restore the original appearance. You need to dissolve a small amount of soap shavings in water, and then thoroughly wash the aluminum object with the solution. To add shine, mix ammonia and borax in a ratio of 1:3 and rub the surface, and then rinse thoroughly with water.

Baking soda

Baking soda can easily remove stains of any complexity. To do this, you need to make a paste out of it by adding a small amount of water, and then just gently rub it for a couple of minutes, depending on the complexity of the contamination. After this, the remaining natural powder is easily washed off with clean water.

Glue and soda

You can clean aluminum from oxidation using a homemade product. You will need to take 100 grams of baking soda and office glue for 10 liters of hot water. All this must be mixed and the required items immersed in this solution. You need to keep the item in such a product for at least three hours, and then clean it well with a sponge.

Recommendations and care tips

Before using aluminum cookware for the first time, it is recommended to calcine it thoroughly. To do this, it is recommended to pour a small amount of sunflower oil and a tablespoon of salt into the bottom of the pan, and then keep it on the fire for a while, stirring the salt. After completing the procedure, it is recommended to wait for the dishes to cool, after which they should be washed thoroughly.

It is not recommended to use abrasive products when washing, as they can remove the protective layer, which will subsequently cause the dishes to darken. If the dishes previously contained dairy products, eggs or dough, then you must first wash the dishes with cold water, and only then use hot water.

If you boil clean water or potato broth in an aluminum container, it may darken. In order for the dishes to acquire shine, you need to add a small amount of ammonia to it each time you rinse. It is also not recommended to store such types of products as pickles and mushrooms in dishes made of this material. And you can’t ferment cabbage in it either.

It is necessary to protect dishes made from this material from mechanical damage, since aluminum bends and breaks easily. This point especially applies to lids. If you follow these few care rules, products made from this material will delight you with cleanliness and shine for a long time.

Source: https://InfoUborka.ru/stati/chistka-alyuminiya.html

Cleaning aluminum from oxides: 20 best folk and chemical remedies

In every home you can find products that are made of durable aluminum. Most often, frying pans, saucepans, fittings, sinks and window frames are made from this metal. Over time, the aluminum surface oxidizes, and therefore every person should know all the features of cleaning aluminum from oxides.

Features of the material

Aluminum is a metal whose surface is painted silver with a slight white tint. This material has certain features that you should familiarize yourself with in advance. These include the following:

• High level of density. Products made from this metal are very durable and are not subject to mechanical damage.
• Good thermal conductivity. This figure is almost the same as that of silver, gold or copper.
• Protection from corrosive plaque. Aluminum structures never rust, but instead of rust, oxide may appear on their surface.

How to clean at home

There are several effective means that will help you clean the aluminum surface from the formed oxide at home.

Soda

To eliminate oxidation that has appeared on the aluminum surface, you can use baking soda. The main advantage of this product is its accessibility, since soda powder is available in almost every home.

Before you begin removing oxides, you need to prepare a solution. To do this, add 150 grams of soda to 300-400 milliliters of water. The mixture is stirred until a thick paste forms. Treat the damaged surface with the prepared mixture and wash it off with water.

Coca Cola

Many people believe that carbonated drinks can only be used as a drink, but this is not true. Housewives use them to remove rust and oxidation from metal surfaces. Among the most effective drinks is Coca-Cola, which will help restore an aluminum product. To remove oxides, the damaged coating is placed in a container with effervescent liquid and left for 40-60 minutes. If there is a lot of oxidation, the procedure is extended to 2-3 hours.

Sorrel

Some people use only oxalic acid, but even fresh sorrel leaves will help remove oxides. First, you need to place a bunch of sorrel leaves in a small saucepan and fill them with cold water. Then the container is placed on a gas stove and boiled for half an hour. When the liquid boils, the aluminum product is soaked in it.

The procedure lasts an hour and a half, after which the soaked surface is rinsed and wiped dry.

Lemon acid

Effective agents that help quickly eliminate oxidation include citric acid. It is added in the amount of two tablespoons to a liter container filled with cold water. Then the solution is brought to a boil, boiled for half an hour and removed from the gas stove. To remove newly appeared traces of oxides, wipe the surface with a sponge soaked in a solution of citric acid. To remove old oxidation, the product will have to be soaked in liquid.

Apple

Fresh apples contain trace elements that help remove oxidized stains from any metal surface. Using this method is very simple. It is enough to cut one apple into two equal parts, and then rub it on the oxidized mark. After 40-50 minutes, the treated coating is washed with soapy water and dried. If the stains remain, the procedure is carried out again.

Mustard powder, vinegar and salt

Sometimes, to eliminate blackening on the surface of aluminum products, products prepared from several components at once are used. A solution made from mustard powder, vinegar and salt is considered effective. The components are mixed to obtain a homogeneous mixture, after which a sponge is soaked in it and the oxidation is wiped off. 20 minutes after application, everything is washed off with warm water.

Salt

Aluminum cookware can be cleaned using table salt. To do this, add 85 grams of salt to a liter of heated water. The components are mixed until the salt particles are completely dissolved in the water. Then soak a cloth in the liquid and wipe the contaminated area. Before using the product, rinse it thoroughly to remove any remaining salt.

Acids

Effective anti-oxidation agents include products that contain natural acids. Most often, people use cucumber pickle, yogurt or regular kefir. Fill the container with any of the listed products, after which the aluminum part is soaked in it. After 10-15 hours, it is removed, rinsed and wiped off from remaining oxidized contaminants.

Sour milk, kefir, brine

These products contain natural acids that effectively fight oxidation. Brine, sour milk and kefir do not have to be mixed, and therefore these products can be used separately. They are poured into a small pan, after which an aluminum part is placed in it. It soaks for about three hours. This is enough to eliminate even old oxides.

Soda and glue

Sometimes serious oxidation appears on the metal, which is difficult to eliminate. In this case, it is better to use a product made from glue and soda. To create it, pour four liters of water into a pan, after which 80 grams of soda and 2-3 tablespoons of adhesive liquid are added to it. The prepared solution is boiled for forty minutes, and then the aluminum part is wiped with the created liquid.

Ketchup

Regular ketchup made from tomatoes will help remove minor oxidized traces. This is an unusual method that housewives do not use very often. The main advantage of this method is that after its use the aluminum surface will begin to shine.

To remove dirt, apply a thin layer of ketchup to the surface and leave it there for 10-15 minutes. After this, it is washed off with running water, and the part is wiped with a dry towel.

Onion

Oxidation that appears on a metal surface can be eliminated using an ordinary onion. To do this, pour water into a saucepan and add a few onion heads. Then the mixture is boiled for 40-50 minutes, after which the part is soaked in the boiled onion liquid. You can also not boil the onions, but simply cut them and wipe the contaminated surface with them.

Garage Recipes

There are several garage recipes that will help you make anti-oxidation products.

Boiling soda

Ordinary boiled water will help remove new traces of oxide. The liquid must be boiled in a small saucepan in advance. Then the boiling water is poured into a basin in which all parts that need cleaning will be soaked. The soaking time lasts about 3-4 hours. Then all products are washed and wiped from any remaining water. If the oxides have not disappeared, you will have to use other, more effective means.

Borax

A dense oxidized film can be removed using a special pharmaceutical borax. To restore an aluminum product, perform the following steps:

• add 10-15 grams of borax to a glass of water;
• stir 3-4 drops of ammonia into the mixture;
• treat the metal coating with the prepared liquid;
• after forty minutes, the remaining composition is washed off from the surface.

Sodium hydroxide

You can remove a layer of stubborn dirt with caustic soda. The advantages of this procedure include the fact that it is easy to carry out at home. The product in an amount of 150-200 grams is added to 7-8 liters of water and mixed thoroughly. It is necessary to use heated water, the temperature of which is 60-80 degrees. The part should be washed with the prepared sodium solution.

Household chemicals

The most effective way to clean aluminum cookware is to use household chemicals. The most commonly used drug is “Mole,” which is used to combat blockages in drain pipes. A few spoons of powder are added to half a liter of water. Oxidized parts are placed in the created solution for two minutes, and then cleaned with a brush and soapy water.

Anodizing as a method of protection

When using this technique, you will have to add purified water mixed with sulfuric acid to a plastic container. A special power source is then connected to the electrolyte bath and to the workpiece. Electricity will be passed through the electrolytic solution. The procedure lasts 35-45 minutes, after which the product is washed to remove loose dirt.

Rules for caring for aluminum cookware

There are several recommendations that will help you properly care for aluminum cookware:

• Products must be washed after each use;
• The dishes should be stored in rooms with an average level of air humidity;
• When washing, do not use abrasive products.

Conclusion

Over time, products made from aluminum begin to oxidize and become covered with dark spots. To get rid of them, you will have to familiarize yourself with common effective methods for cleaning aluminum coatings.

Source: https://hozzi.ru/chistka/alyuminiya-ot-okislov

Cleaning and Maintaining Your Anodized Aluminum Trim

As with any prefabricated building material, aluminum requires reasonable care before and during installation, as well as periodic cleaning and maintenance after installation.

Although anodized aluminum is exceptionally resistant to corrosion, discoloration and wear, its natural beauty can be marred by harsh chemicals, abuse or neglect.

We recommend you the website of the Profile Center company; on the official website of the manufacturer you can buy a Z-shaped aluminum profile for tiles and steps.

Such conditions usually only affect the surface finish and do not reduce the service life of the aluminum. All exterior surfaces collect varying amounts of soil and dirt, depending on the geographic area, environmental conditions, finishes, and location on the building.

These factors and the owner's attitude towards the surface's appearance will determine the type and frequency of cleaning required. An aluminum cleaning schedule should be integrated with other cleaning schedules for efficiency and savings.

For example, glass and an aluminum curtain wall can be cleaned at the same time.

Cleaning may be required more frequently in one geographic area than another when appearance is of utmost importance. Industrialized areas will require more frequent cleaning than rural areas. Seasonal precipitation can influence washing frequency by removing water-soluble deposits and less adherent soil.

In foggy coastal areas, frequent cycles of condensation and drying can lead to the accumulation of salts and dirt in the atmosphere, which can cling tenaciously to the surface. In climates where precipitation is low, the possibility of atmospheric surface washing is minimal.

For example, Los Angeles, with its unique combination of limited rainfall, temperature fluctuations, smog and condensation, requires aluminum to be cleaned more frequently than other urban areas with more frequent precipitation.

In both wet and dry climates, sunken and sheltered areas tend to become more contaminated due to lack of rain flushing. More frequent and longer periods of condensation also occur in protected areas, increasing soil adhesion.

This especially applies to soffit areas on eaves, bottoms of façade panels, closed column caps, etc. Periodic maintenance prevents long-term soil buildup, which under certain conditions can accelerate the weathering of the finish.

Cleaning anodized material rulers

Cleaning procedures for aluminum should be initiated as soon as possible after installation is completed to remove construction soil and accumulated environmental contaminants and discoloration.

Selecting a cleaning solution

Like painted surfaces, anodized surfaces should be cleaned using mild soap solutions to maintain their original beauty. Products that are safe to use with bare hands can be safely used, including most commercial cleaners. The cleaning solution should be applied with a soft cloth, sponge or brush. Avoid using strong acidic or alkaline cleaners.

Cleaning work should begin at the top of the building and continue down to ground level in a continuous fall. Using a strong spray of water, wash the area the width of the step or scaffold as you clean from top to bottom.

Because surface soils can be light or heavy, several more stringent cleaning procedures may be used depending on the severity and strength of the soil. Only a trial and simplest soil removal procedure is the one that should be used.

Easy soil removal

For light soils, the simplest procedure is to flush the surface with water using moderate pressure. If soil is still present after the surface has dried, you should try brushing or sponging and spraying with water at the same time.

If the soil still sticks, you should use a mild detergent with a brush or sponge. Washing should be done with even pressure, first horizontally and then vertically.

After washing, the surfaces must be thoroughly rinsed by spraying with clean water.

If it is necessary to remove oil, wax, polish or other similar materials, it is recommended to use MEK or a similar solvent for cleaning.

Special care should be taken when using these types of solvents as they may damage organic sealants, gaskets and finishing materials.

These solvents should never be used on anodic surfaces protected by clear organic coatings unless the organic coating has deteriorated and must be removed.

Source: http://moydomovoy.com/ochistka-i-uxod-za-vashej-anodirovannoj-alyuminievoj-otdelkoj/

How to remove oxidation from aluminum on an engine?

Let's pour some liquid over the KPE, and then use a stream of warm water to wash everything off under pressure. Engines are washed in this way perfectly. If only we could find something for aluminum.

A suitable liquid is caustic soda or potassium - alkali (not lye). Works perfectly without any jet. Everything becomes like new. White matte color. Be careful with dilution. Read about the process on the internet.

Search in railway battery services, etc.

If you can't find it in its pure form, it is found in drain cleaning fluids. It works too.

* Products made of aluminum and its alloys are etched in alkali solutions of different concentrations depending on whether their surfaces are polished (metal polishing) or unpolished: polished surfaces are etched in 1-2%, and unpolished ones are etched in a 5-10% caustic solution sodium hydroxide at a temperature of 60-70°C for 1-1.5 minutes.

The degreased part is immersed in the solution and immediately removed or wiped with a dampened swab, and after drying, wiped with a clean rag. To brighten aluminum, the oxide film is easily removed by a mixture of borax solution (50 g/l) and 25% ammonia (5 ml/l).

Aluminum products pickled in alkali are washed and illuminated for 5-10 minutes with a solution of nitric acid (concentrated) in water (30-40 and 100 parts by weight, respectively). When brightening products made of silumin - aluminum alloys with silicon (alloy AL2, AL4, AL9, VAL5) - add 1-3% hydrofluoric acid to nitric acid and treat them for 5-10 minutes.

After acid etching, the part is washed in cold and then in hot water.

Aluminum parts are etched in nitric acid only after its chemical oxidation. In electroplating, aluminum is treated in other solutions after alkali.

*
To make aluminum cookware shine like new, prepare the following composition. For half a bucket - a bucket of warm water 100g. silicate glue (sold in office supplies) and 100 g of soda ash (sold in hardware stores). Bring all this to a boil and add our dishes to the composition. Boil for 20-30 minutes, then turn off and leave the dishes in the composition until cool. (At the same time, you could also put gas burners there.)

*
Boiling a weak solution of baking soda in a darkened aluminum pan will give the inside of the pan a nice matte white color.

A suitable liquid is caustic soda or potassium - alkali (not lye).

If you can't find it in its pure form, it is found in drain cleaning fluids.
It works too. How it works, cheap and cheerful, I used a liquid called Mole

Questions about how and how to clean aluminum are relevant for many.

Aluminum products are distinguished by their lightness, convenience and beautiful shine, but as a result of use they quickly darken, become covered with plaque or oxide, which spoils the aesthetic appearance and interferes with the full use of the item. To restore the shine and purity of aluminum, use folk remedies and special household chemicals, follow the recommendations for care and use.

General recommendations

Aluminum is a soft metal that requires careful handling during operation and cleaning. To clean products from various types of contaminants and not damage the material, follow simple recommendations:

1. Do not use metal scrapers or brushes, hard scourers or sharp objects . These tools damage the surface, leaving scratches and other unsightly marks. After such treatment of the dishes, aluminum particles can get into the food, which will negatively affect the taste of the dish and its benefits.
2. Do not clean aluminum alloy products with abrasive agents (sand, powder).
3. Kitchen utensils should be washed only after they have cooled down . Hot metal deforms when interacting with water, and it is almost impossible to return its original appearance on your own.
4. such as acids or alkalis for cleaning They spoil the aesthetic appearance, and the resulting chemical reaction can lead to the release of toxins or heavy metals that are hazardous to health.
5. To achieve the desired effect, choose a cleaning method and cleaning product based on the type and degree of contamination .
6. Do not wash aluminum cookware in the dishwasher . Temperature changes negatively affect the metal and increase the risk of deformation and corrosion.
7. To make the product shiny, polish the surface with a sponge dipped in a solution made from borax and ammonia in a ratio of 3:1.

Do not wash aluminum cookware in the dishwasher.

How to clean aluminum oxide at home

Aluminum is susceptible to oxidation. As the product is used, the oxide layer grows, which leads to the appearance of dark spots that cover the entire surface or individual parts.

  Which is harder, aluminum or brass?

You can clean oxide and blackness at home using available folk remedies :

1. Soda . Dissolve the product in a small amount of water to obtain a paste. Apply the mixture to the stain and work the surface in a circular motion.
2. "Coca Cola" . Fill the item with soda and after 1.5 hours wash it with water.
3. Sorrel . Place a bunch of fresh sorrel in a container that needs cleaning and fill it with water. Place the dishes on the stove and boil the mixture over low heat for 30 minutes. Drain the solution and rinse the product.
4. Lemon acid . In a saucepan, combine 2 tbsp. l. citric acid and 1 liter of water. Boil the solution for 15-25 minutes, depending on the degree of contamination, and then wash the container with clean water.
5. Apple . Rub the darkened, oxidized mark with half the fruit and leave for half an hour for the malic acid to take effect. After the time has passed, wash the container with detergent.

Source: https://varimtutru.com/kak-ubrat-okislenie-s-alyuminiya-na-dvigatele/

Anodizing Aluminum Surface

When interacting with atmospheric oxygen, aluminum almost instantly oxidizes with the formation of a thin (less than 0.1 micron) film of Al2O3 oxide on its surface. Despite such a small thickness, such an oxide layer has a fairly high density and protects the metal itself from further oxidation.

To increase the thickness and improve the physical and chemical properties of the oxide coating, industry uses the so-called oxidation, i.e. the artificial creation of a metal oxide film on the surface of the product by carrying out an oxidation-reduction process.

In general, oxidation is applied to many metals (and alloys based on them) and non-metals (for example, Si), distinguishing between thermal, chemical, electrochemical and plasma oxidation methods.

The oxidation of products made of aluminum and its alloys primarily means electrochemical oxidation, or anodic oxidation. In industry and modern literature, the term “anodizing” is most often used to designate this process.

Thus, anodizing - anodic oxidation - of aluminum products (and alloys based on it) is the electrochemical oxidation of the aluminum surface of the product in order to create on it a durable oxide film that has protective (or protective-decorative) properties in relation to this product .

Process mechanism

Let us consider the mechanism of formation of an oxide film on an aluminum surface during its oxidation under the influence of an electric current.

Rice. 1. Diagram of an electrolytic cell for anodic oxidation of aluminum. (1) – anode; (2) – cathode; (3) – container with electrolyte; (4) – anode contact; (5) – direct current source; (6) – anodized products; (7) – electrolyte solution.

Closing the circuit initiates a flow of electrons and negatively charged ions towards the anode, while protons move in the opposite direction. As a result, the following processes occur on the electrodes:

At the cathode: 6H+ + 6e_ → 3H2 (hydrogen gas is released)

At the anode: 2Al0 + 3H2O – 6e- → Al2O3+6H+ (the surface of the product is oxidized)

The total reaction of anodic oxidation of aluminum is written as follows: 2Al + 3H2O Н+,☇ Al2O3 + 3H2

The amount of aluminum oxide formed directly depends on the amount of electricity consumed, i.e. transit time and current density. The nature of film formation is largely determined by the nature of the electrolyte used.

In particular, when anodizing in a solution of sulfuric acid, an oxide layer is formed according to the following scheme.

At the first stage, a thin layer of aluminum oxide is formed (the so-called “barrier layer”), and then a relatively thick porous film with a hexagonal cellular structure is formed (Fig. 2.)

After the film reaches a given thickness (usually 15–20 microns), the process is stopped, and the resulting porous structure is smoothed out by hydration, which makes the oxide layer stable under various external influences. In industrial terminology, this procedure is called “compaction”.

The porosity of the oxide film turned out to be useful from the point of view of the decorative properties of anodized products, since such a structure makes it possible to introduce dyes into the surface layer by, for example, physical adsorption. It is enough to immerse the anodized workpiece, which has not yet undergone the compaction procedure, into a solution of the appropriate dye to obtain a product of the specified color.

Moreover, the coloring obtained in this way significantly improves in its physical properties in comparison with classical (liquid or powder) painting, due to the localization of the light-absorbing substance deep in the pores, and not on the surface of the metal.

Currently, there is a wide range of soluble dyes used for decorating anodized products, both by physical adsorption and under the influence of an electric field (electrolytic coloring of anodized aluminum and its alloys).

Rice. 2. Structure of the aluminum oxide layer obtained by anodic oxidation in a sulfuric acid solution of 18 – 20 wt%.

Preliminary surface treatment before anodic oxidation

The final appearance and quality of products that have undergone the full technological cycle of anodic oxidation are largely determined by the composition of the alloy being processed, the history of the production of workpieces and the preliminary preparation of the surface before anodizing.

As a rule, an aluminum workpiece (cleaned from oil, mechanical and other types of contamination) is subjected to a chemical etching procedure, primarily designed to remove the natural Al2O3 layer from the surface.

Depending on the type of etching solution, the surface texture of the final product varies from slightly satin (with varying degrees of residual gloss) to deeply matte. In some cases, chemical etching is combined with mechanical processing (brushes, abrasive belts, grinding wheels, etc.), leading to an ordered (directional) surface structure.

The use of mechanical processing makes it possible to obtain a more reproducible result and eliminate defects in the alloy that chemical action cannot cope with.

According to the European classification [ISO 7599:2010(E)], there are nine methods of pre-treatment of anodized products, including either only chemical or only mechanical effects, or a combination of both. Two of them - the so-called "E0" and "E6" - are the most common types of chemical etching that do not require mechanical processing.

The first one is the simplest. In this case, the surface is only degreased and roughly etched. All defects (scratches, etc.) remain visible, and the products have a natural metal color. In the case of E6, mechanical defects are visually smoothed out and the surface becomes matte.

For this reason, this type of etching is often called "matting" or "satinizing".

Currently (especially in the case of anodizing aluminum profiles), matting is carried out in alkaline solutions with various additives at a high concentration of dissolved aluminum. In this case, a relatively large amount of aluminum passes from the surface of the products into the solution (50 – 100 g/m2). Due to the fact that defects are only smoothed out, but not completely eliminated, acid “matting” is sometimes used.

After the etching process, a dark coating (sludge) appears on the surface of the products, due to the content of alkali-insoluble components in the alloy (some oxides, intermetallic compounds, silicon, etc.). The resulting sludge can be removed by immersing the products in a 25 - 50% HNO3 solution.

At room temperature, 3–5 minutes of such treatment is sufficient to obtain a plaque-free surface.

The process of cleaning up pickling sludge is called “clarification” (equivalent terms “deoxidation”, “picking”, “neutralization” are also often used in the literature and industry).

Currently, most enterprises refuse to use nitric acid to brighten the anodized surface and prefer to use sulfuric acid in combination with special additives for these purposes. Using a H2SO4-based clarification solution containing Alfideox 75 allows you to:

• get rid of problems associated with the content of toxic derivatives of nitric acid in wastewater;
• reduce the redox activity of wastewater;
• avoid contamination of anodizing and electrolytic dyeing solutions with nitrates;
• eliminate rinsing baths before anodizing, resulting in significant savings in water and work space in the workshop;
• use waste anodizing electrolyte, i.e. significantly reduce the cost of preparing a bath.

Thus, clarification is the final stage in preparing products for anodic oxidation.

Final processing

Products that have undergone a full cycle of preliminary preparation are sent to an anodic oxidation bath, in which a forced growth of an aluminum oxide film on the surface occurs. The mechanism of formation of the oxide film has already been discussed in detail above, so we will immediately move on to the processes of final processing of the anodized surface.

As already mentioned, the resulting oxide layer has a porous cellular structure, which, on the one hand, forces one to take special measures to smooth it out (compact the pores), and on the other hand, it turns out to be useful from the point of view of imparting decorative properties to the product, since it makes it possible to introduce dyes into the surface layer. In modern technological processes, there are three main methods of painting aluminum products that have undergone anodic oxidation:

• Adsorption coloring (the not entirely correct term “chemical” coloring is often used), based on the physical adsorption of dye molecules by a porous surface;
• Electrolytic coloring is the deposition of a substance that absorbs visible light into a near-surface layer under the influence of an electric field;
• Interference coloring (a relatively new and promising direction in industrial anodizing) is a method of giving a product a particular color, which is based on the interference of light rays refracted in pores with different optical properties. The use of dyes in the classical sense of the word is not implied here.

At the final stage of the entire anodizing technological chain, the procedure for compacting the anode layer is carried out. Filling the pores of the cellular structure is usually carried out either by hydration, treating the products with hot demineralized water or steam, or by reaction with inorganic salts. The first method is currently the most common.

It is based on the absorption of water molecules by the pores with the subsequent formation of boehmite [AlO(OH)], “cementing” the cellular structure. It should be noted that as a result of such treatment, a powdery deposit is formed on the surface (the so-called “sealing deposit”), to prevent which special chemical composites are introduced into the solution in advance.

The macroscopic parameters of the hot water compaction process have a strong influence on the quality of the final result. Particular attention should be paid to temperature, pH of the environment and the degree of purification of the water used.

So, the temperature should tend to the boiling point; permissible range of pH values ​​5.6 – 6.6; The degree of water purification should be maximum, and the presence of impurities such as phosphates and silicon compounds is unacceptable.

Due to the fact that the temperature of the hot compaction bath is maintained at a high level, this process, on the one hand, is quite energy-intensive, and on the other hand, it imposes certain instrumental difficulties associated with the constant evaporation of the bath’s contents. Both of these factors increase production costs. These problems can be partially solved by using various techniques.

To reduce evaporation, for example, it is recommended to cover the surface of the solution with special polymer floats. In general, the current situation has prompted the development of alternative low-temperature methods for compacting the anode layer, and in recent years, techniques for filling the pores of the cellular structure by reaction with cobalt or nickel salts are increasingly used.

As an example, here is a diagram of the chemical reaction underlying cold compaction using the special additive Alfiseal 982: Al2O3 + 2NiF2 + 4F- + 3H2O → Al(OH)F2 + 2Ni(OH)2 + OH- + AlF63-

The most effective from the point of view of the optimal price-performance-quality ratio is considered to be the scheme for final processing of an anodized surface, combining sequentially the processes of cold and hot compaction with the use of appropriate chemicals and additives.

This allows you to significantly reduce the cost of additional heating of baths and the average processing time of products with high quality. However, it should be taken into account that in most cases the combined compaction requires a short final drying time, and the waste wash water contains heavy metal ions (in particular nickel).

The latter fact should be taken into account when designing treatment facilities.

Source: https://alufinish.ru/articles/282-anodirovanie-alyuminievoj-poverkhnosti

How to remove black anodized aluminum - Articles

Anodizing creates a hard layer on the metal that makes it more durable and weather-resistant, but over time anodized surfaces develop scratches that cannot be cleaned or polished.

Like most things, the darker the color, the more imperfections appear, making black anodizing one of the worst colors to show scratches and tinnitus.

Since anodizing is a chemical process in selection, another chemical process is required to remove the anodized aluminum; this process is much simpler.

directions

Color anodizing makes aluminum clotheslines more durable (image by grands et petits by Patrick EMIN from Fotolia.com)

1. Remove aluminum parts from other items if possible. If you can't do this, cover nearby items with plastic and tape to prevent them from being damaged during the anodizing removal process.

2. Fill a 4-quart container with warm water and add 1 tablespoon of drain cleaner.

3. Mix drain cleaner in water and place the aluminum parts in a container. If you cannot remove the parts, apply the cleaner directly to them using a sponge.

4. Remove parts from container every 1-2 minutes to clean off soot, called soot, with a cloth. Place the parts back into the container and repeat the process every 1-2 minutes until the anodizing is removed. For non-moving parts, wipe with a cloth every minute to remove soot and reapply the cleaner with a sponge. Repeat this process every 1-2 minutes until all anodizing has been removed.

5. Rinse parts thoroughly with cold water. Rinse the pieces separately in a container or with a hose. Spray the attached parts with water or wash with a sponge.

tips

• Wear gloves and safety glasses when handling cleaning products.

warning

• Use the drain device only in a well-ventilated area.
• Removing the anodizing reduces the durability of aluminum. It must go through the anodizing process again to have the same durability as before.

What you need

• Plastic sheets
• Adhesive tape
• 4 liter container
• Drain cleaner
• sponge
• rag
• Hose or water bottle

Source: https://ru.laermfeuer.org/remover-anodizacao-preta-aluminio-como_205423-10875

How to clean aluminum: how to clean technically oxidized metal from paint or cleaning sulfate on a burnt pan until it shines

Aluminum is believed to be resistant to corrosion, but this is not true. Aluminum is a highly reactive metal. Under the influence of oxygen and moisture, it oxidizes.

This process is accelerated due to aggressive environments and the presence of certain materials near aluminum. As a result, the metal darkens and becomes covered with a loose layer of oxides. Let's try to figure out how to clean aluminum from oxidation and what is needed for this.

How to properly wash aluminum cookware

Among all types of kitchen utensils, most housewives choose aluminum cookware. This is easy to explain - this metal heats up very quickly, the heating is uniform, the dishes withstand wear well, are light in weight, which is very convenient during operation.

Aluminum products have a bright shine, but over time this shine is lost - the metal becomes covered with grease, white coating or dark spots.

To clean kitchen utensils, most women use a regular dishwashing detergent. There will be an effect, of course, but it will be insignificant. There are several secrets that allow you to wash aluminum more effectively:

• You only need to wash dishes that have cooled completely. If you wet hot metal, there is a risk of deformation.
• If there are burnt food residues inside the pan, fill the pan with warm water and add detergent to it. Next, the water should be left for about an hour. After this, burnt food remains will come off easily.
• You should not try to clean dishes with acids and alkalis - after such cleaning, dark areas may form on the surface. It must be remembered that alkali and acid deprive aluminum of its shine.
• It is better to wash products made of this metal by hand - if you wash it using hard brushes and metal sponges, then traces will certainly remain on the surface.

How to clean aluminum from corrosion products and oxides

Let's see how to remove corrosion, oxidation, soot, plaque and other contaminants:

• To combat dark spots, use sour milk, kefir, and brine. Fill the bottom with any of these products and leave for 12 hours. Then you need to rinse the product thoroughly under running cold water. Next, all the darkening will be washed off with a regular rag.
• Soot removes sour apple well; you can also use lemon. To do this, cut it in half and rub half over the surface to be cleaned. Due to the action of acids, carbon deposits can be removed very quickly.
• You can remove the oxide using salt and warm water. The solution is prepared in equal proportions. The water temperature can be any, the most important thing is that the salt is completely dissolved in it. Then, using this solution and a sponge, you can clean the surface.

Vinegar is an effective remedy

This method of caring for aluminum cookware and products is quite simple and effective. You need to take vinegar or vinegar essence. Soak wipes in the liquid and clean the contaminated area. Vinegar will easily remove oxides of varying complexity.

If the dirt does not budge, then treat the part in boiling vinegar. The liquid is brought to a boil and then cooled. When the vinegar has cooled, you can start cleaning the part being processed. If the contamination is severe, then the product is boiled in vinegar.

Soda and glue against old oxides

You can clean oxides and carbon deposits using these substances. At home, you can prepare a very strong product that will not only make the aluminum part clean, but also give it a new look.

Hot water is poured into the container, and then baking soda and glue are added to it. The ingredients are taken in the following proportions: for 10 liters of water you need 100 g of soda and 100 g of office glue.

All components must be mixed thoroughly.

You also need a small bar of regular soap, grate it and add it to water with glue and soda. The workpiece is placed in the prepared solution for 2-3 hours. Then, when time has passed, you need to rinse the product in water and wipe dry with napkins. This method will remove the oxide film.

Recipes from the garage

Some car parts are also made of aluminum. They often undergo oxidation and require cleaning. Car enthusiasts have developed effective ways to clean parts even from complex oxides:

• Take a liter of water for 2 tablespoons of soda. The product is immersed in the solution and then boiled. The process should be controlled. After just 10 minutes of cleansing, a visible effect appears. It may take several boils to get aluminum perfectly clean.
• You can remove the oxide film from aluminum using borax. For 10 g of substance you need a few drops of ammonia. It is enough to apply the solution to the surface of the aluminum parts and let it dry (about 30 minutes). After this, wipe the part with a dry cloth.
• Caustic soda cleans aluminum well. You need to prepare a solution: take 1-2 teaspoons of caustic soda per 1 liter of water. A part is placed in the resulting mixture and a violent chemical reaction is formed. Within five minutes there will be no trace of an oxide film on the surface. Next, all that remains is to rinse the treated parts with water.

Source: https://xn----8sbna6aihebzq3cl.xn--p1ai/drugoe/rekomendatsii-o-tom-chem-ochistit-alyuminij.html