Blackening aluminum at home - a simple recipe

Sometimes, to install exotic lenses on a camera, you have to order adapters for them from a turner. Mostly they turn me out of duralumin, aluminum and less often from steel. It is known that to increase the contrast in a photograph and to avoid stray light, you need to thoroughly blacken such a homemade adapter.

I have been looking for a long time for an acceptable method of blackening metal that could be used at home and obtain acceptable blackening quality.

The most affordable option seemed to be to buy a can of matte black paint and paint over the necessary parts. But even this method is not so simple. We need to prepare the environment, and definitely not in the apartment, but at least in the garage. And besides, the paint can be easily scratched.

I will generally keep silent about the anodizing method; it requires increased safety precautions and all sorts of experiments with sulfuric acid do not suit me.

Just recently I learned about the method of blackening with ferric chloride. Purely by chance - one person at the market said that he dips shiny parts in waste from etching printed circuit boards and thus gets a good blackening. I thought it was a good idea, but in general it’s not necessary to look for waste, it’s enough just to find ferric chloride (FeCl3) and make the same solution.

I found ferric chloride and ordered it online from a private seller on a bulletin board; a 200 g bag cost me about 50 UAH with postage.

I was pleasantly surprised, since ferric chloride is mainly sold for radio amateurs. I myself used to be interested in radio engineering, about 15 years ago, and I thought that now this industry had long been supplanted by Chinese ready-made radio solutions. It turned out that they were not forced out, since there is a supply for ferric chloride, there is also a demand. But I won’t go off topic, further on…

I ink aluminum, duralumin, steel and brass using this method. And I can say that it worked best with aluminum. The duralumin was slightly worse, but acceptable. The steel did not turn black, but became covered with a coating reminiscent of rust, it stopped shining, at least this way, it was still a little better than it was. The brass changed color a little - it became a little redder, stopped shining, became matte, but did not turn black.

Black oxide coating on aluminum and alloys

The method, outlined in the US patent, forms a layer of black oxide on the surface of aluminum or an aluminum alloy during just one processing step .
1. In the proposed technology, the surface on which the black oxide layer is to be formed is first cleaned to remove any oils and other components that may interfere with the formation of the oxide layer.

2. After cleaning, the surface is rinsed with tap water and then immersed for 30 minutes in the below solution, maintained at a temperature of 80°C to 90°C. The result is an acceptable black oxide layer having a thickness of about 500 A.

3. After treatment, the surface is washed with distilled water and then dried with air at room temperature.

Compositions of solutions for chemical oxidation of aluminum and aluminum alloys:

It is important to note that both methods provide a black coating not only on aluminum, but also on a variety of its alloys, including aluminum-manganese alloys (e.g. AA 3102), aluminum-silicon alloys (e.g. AA 4047) and aluminum-zinc alloys (e.g. ,AA 7072).

Source

Methods for removing scale from aluminum cookware

Aluminum cookware is susceptible to scale formation. This is due to the high content of heavy metal salts and lime deposits in tap water. To fix the problem and return the kettle, saucepan or can to shine and cleanliness, you need to properly clean and wash the products in a timely manner.

Vinegar

Algorithm for cleaning an aluminum kettle:

To get rid of the unpleasant vinegar aroma after cleaning, place an orange/lemon peel in a bowl, cover with water and leave for 15 minutes. This trick will create a pleasant aroma and freshness.

Lemon acid

Instructions for descaling aluminum:

Blackening aluminum at home: means, methods, procedures, tips

Due to the fact that most steel grades are susceptible to corrosion, they begin to rust when in contact with water. This can also happen if the product is placed in a room with high humidity. Of course, the corrosion process can be prevented if the steel surface is wiped dry every time. Anti-corrosion paint is mainly applied to metal products using a brush or by spraying.

However, this is not a solution to the problem if the design includes threaded connections or moving parts. The best option in such cases would be the bluing process. Despite the fact that rust does not form on aluminum, judging by the reviews, it happens that the owner wants to blacken this metal. This procedure can also be recommended for this purpose. It is also called blueing. But if we adhere to technical terminology, then this process is more correctly called oxidation. How to blacken aluminum? What will you need for this? You will find information on how to blacken aluminum at home in this article.

Features of bluing with citric acid

It is worth noting that bluing with citric acid is not very durable, so you should not use it for etching handles and knives that are regularly used in cooking. When the procedure is performed correctly, the color of the finished product is even and free of various stains, streaks and other imperfections. It is worth noting that when carrying out bluing it is necessary to pay special attention to several points:

1. Steel quality. High carbon steel lends itself best to bluing. Other types of steel may be painted in a lighter shade or have an uneven color.
2. When performing the procedure, it is necessary to have good ventilation, as harmful gases are released during the process. If bluing is done in the kitchen, be sure to turn on the hood or open the window.
3. The entire bluing process must be carried out under constant supervision, as it is recommended to turn the metal over every few minutes to ensure uniform etching.

If the bluing technology has not been violated, then after just half an hour or an hour you can get high-quality processed metal.

What is the essence of the procedure?

Before you start blackening aluminum at home, you should understand what the meaning of this process is. According to experts, its essence is to create conditions in which a film of iron oxide would form on a metal surface. Depending on which method of aluminum bluing was chosen, its thickness can range from 1 to 10 microns. There are three ways to influence metal. Consequently, blackening of aluminum at home can be thermal, acidic or alkaline. In the first case, the product is heated, and in the other two it is processed in an appropriate solution. During bluing, the tarnish colors on the surface will change. The master only needs to decide on the desired color of oxidation and stop the process in time.

Characteristic

The melting point of materials is determined by their purity. Due to its lightness and good ductility, aluminum is suitable for various technological procedures. Under the influence of high temperatures, a reaction with oxygen occurs.

An oxide film appears on the surface of the metal, protecting it from oxidation and corrosion. During melting, aluminum changes its structure, so it needs a protective coating. With sudden cooling, additional internal stress and shrinkage appear.

About ferric chloride

Judging by the reviews, some home craftsmen etch printed circuit boards and thus obtain a liquid for blackening aluminum. Next, shiny metal parts are lowered into this mining for a certain time. Those who are interested in how to blacken aluminum at home can be advised not to complicate the process by etching the boards, but to immediately acquire ferric chloride to make the required solution. You can work with this method both with aluminum and with duralumin, steel and brass.

Judging by the reviews, aluminum surfaces are best blackened. With duralumin the situation is somewhat worse. Steel ones, according to the craftsmen, practically do not blacken. However, they develop a specific coating that can be confused with rust. However, the steel surface is no longer so shiny and looks much better. Brass products after treatment in ferric chloride also do not become black, but acquire a matte reddish tint.

aluminum bluing

Greetings to forum members, I don’t know if this topic has been raised, but I wanted to know whether it’s realistic to bury aluminum in a house.
conditions? Try Aluminum Black or Aluminox for blackening aluminum surfaces.

I’m also interested, has anyone tried to coat an MP-153 box with the following composition: Aluminum Black (the box seems to contain aluminum), is it worth taking this burnishing?

I blued it with duralumin, the effect even after thorough degreasing is poor, everything is stained, gets dirty and wears off quickly. Everything can be solved by sanding the surface and immediately applying a burnisher (before oxidation begins). Rub thoroughly in several layers, then wipe with oil. It turns out smooth, doesn’t wash off so quickly, but the coating is scratch-resistant.

I once read about this method: take egg white, let it sit for a day, then apply it to an aluminum part and let it dry. Then heat the part until red hot. After cleaning, the part will turn black. I haven’t tried it myself, I can’t say how realistic the method is.

AP topic, once again - who blued the MP-153 box with this composition?

dropped an aluminum part into a pan with “Whiteness”, the housewives add the product for washing. After 10 minutes I took it out.. it’s black, like it’s from Africa. the coating does not wear off.

drMoro

I took it out for 10 minutes... it’s black, like it’s from Africa.

Here’s a man who blued a luminium pistol with a fully written recipe and photos: https://guns.allzip.org/topic/87/376775.html

don't miss the topic, AP AP AP

On the contrary, I would like to scrub the aluminum pot. it is all black, covered in soot after 3 years of use on fires. You can wash it with anything, but it’s still blued on the outside.

akira82, well then you need to create a topic “HOW TO OPEN YOUR BOILER”)))))

The point is, rather, not in the bleach, but in the sweatpants that were in the pan

drMoro

As you say. Need data. Brand of “whiteness” (ours or imported), pure or in solution, heated or room. We know the time.

I want to give some advice to the community. It’s not really an advertisement, it’s just a person collecting orders (I ordered), including a solution for bluing aluminum, but not everyone goes to that thread. Maybe someone will be interested. https://guns.allzip.org/topic/54/890044.html

drMoro Whatever you say. Need data. Brand of “whiteness” (ours or imported), pure or in solution, heated or room. We know the time.

Not all aluminum has a blue finish. I held one sample - black. And the next day I lay there and at least fuck the village

thomas60

Not all aluminum has a blue finish. I held one sample - black. And the next day I lay there and at least fuck the village

Yes sir. for example, an aluminum basin for washing clothes turned black after adding ammonia water to soaked clothes. but a tube made of aluminum alloy ad-31 does not turn black like that. For aluminum, you need either anodizing or chemical zinc plating followed by blackening of the galvanized coating.

Source

How to burnish with iron chloride? Where to begin?

If small-sized aluminum products are to be processed, then you can limit yourself to 15-20 grams of this substance. Blackening aluminum at home using ferric chloride consists of several stages. First of all, you should prepare everything for work. First, ferric chloride is diluted with water. It is important that the mixture is easy to spread. To make it thick and not spread, you need to take a small amount of water. Next, the solution must be given time to brew. During this time, you can prepare the product itself for bluing: remove dirt and dust from its surface, and then degrease it. Judging by the reviews, it is enough to wash it under the tap with soap.

Progress

If the solution is prepared and the aluminum surface is cleaned, you can proceed directly to bluing. You will have to work with a stick with cotton wool wound at one end.

Using this stick, scoop up the mixture and apply it to the desired area. At the same time, you need to make sure that it does not spread, but remains in place. Afterwards, the product should be left for some time, without interfering with the chemical reaction. To make it flow faster, experts recommend diluting ferric chloride with warm water. According to home craftsmen, aluminum will turn black within 10 minutes. Aluminum products will have to be burnished longer - the chemical reaction will take half an hour.

Video

To understand the nuances of cleaning aluminum, watch the following videos:

Young mother, wife and part-time freelancer. Being a lawyer by training, I am accustomed to collecting and providing the most complete and reliable information. Constantly improves in the professional field and strives for personal growth and development.

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The habit of using an automatic washing machine “sparingly” can lead to the appearance of an unpleasant odor in it. Washing at temperatures below 60℃ and short rinses allow fungi and bacteria from dirty clothes to remain on internal surfaces and actively multiply.

Threads made of gold and silver, which were used to embroider clothes in the old days, are called gimp. To obtain them, the metal wire was pulled for a long time with pliers to the required fineness. This is where the expression “to drag out the rigmarole” came from - “to do long, monotonous work” or “to delay the completion of a task.”

Before removing various stains from clothing, you need to find out how safe the selected solvent is for the fabric itself. It is applied in a small amount to an inconspicuous area of ​​the item from the inside out for 5-10 minutes. If the material retains its structure and color, you can move on to stains.

How to blacken with olive oil and egg white?

The essence of this method is as follows. First, the aluminum part is carefully polished with fine-grained sandpaper. Next, it is degreased in a soda solution. Then olive oil is applied to the product and heated using an alcohol lamp. It is very important that the flame does not produce soot. Heat treatment should be carried out until a black color appears on the surface. During this time, the oil will burn out and will have to be reapplied. According to experts, the part will have to be lubricated often. Afterwards the surface is cooled and wiped thoroughly. The method using an egg is practically no different from this procedure. The only difference is that it is not olive oil that should be applied to the surface, but beaten egg white. It is advisable that it sit in a warm place for a couple of days before bluing. When it dries sufficiently on the part, it begins to be heated until red hot. At the end, the protein should fall behind, and the aluminum underneath will turn black.

How to bury an aluminum device

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#1 WhiteRus

• User
• 1,427 messages
• Voronezh city
  SOGMP

  Friends, I bought an airsoft pistol for the occasion. Painted.

  From here there are a couple of questions for knowledgeable comrades:

  1. Is paint stripper from a hardware store suitable to remove this Chinese paint from the barrel (HFC device brand)?

  2. How to inexpensively bury a pistol. Material - aluminum alloy (silumin, most likely)?

  Anodizing will not work. I don’t think very well about all these “ammonium nitrates” and other “ethyl-alkane-propyl”. Recommend something simple and effective. I read somewhere that the bluing effect can be achieved by throwing the detailing into “Belizna” chlorine bleach. Who knows?

  #2 Storm2200

• User
• 37 messages

• City: St. Petersburg

I won’t say anything about bleach, but in nature there are all sorts of compounds for chemically coloring aluminum. There are doubts about “cost-effectiveness”.

#3 WhiteRus

• Voronezh city
  SOGMP

  Aluminum burners (I read on specialized forums) burnish aluminum. And they refuse to burnish the aluminum-silicon alloy (silumin). As a result, half a mower into the wind and at the finish line - a spotted gray light.((((

  I won’t say anything about bleach, but in nature there are all sorts of compounds for chemically coloring aluminum. There are doubts about “cost-effectiveness”.

  I read this thread half an hour ago))) Thank you.

  #4 Storm2200

• User
• 37 messages

• City: St. Petersburg

Isn’t it easier to polish it and turn it into a chrome version?

#5 WhiteRus

• Voronezh city
  SOGMP

  Isn’t it easier to polish it and turn it into a chrome version?

  and for a refresher on the GV with a chrome-plated Mauser)))) We will scare the red ones with the shine)))

  #6 Trofim

• User
• 3,372 messages

• City: Prokhladny - Moscow

Isn’t it easier to polish it and turn it into a chrome version?

Not an option for recon

#7 WhiteRus

• Voronezh city
  SOGMP

  Not an option for recon

  the paint looks terrible squalor((((

  Chemists. Respond! Is it really true that no one blued the strike pipes for the recons?

  #8 Uncle Misha

• User
• 159 messages

• City: Nizhny Novgorod region.

I wish you all good health! Only paint is not expensive. Buy MATTE black paint in a can. Sold in auto stores. The parts must be sanded using “zero” sandpaper. Pay special attention to concave corners. Degrease the surface very well. Paint the part and let it dry well, about five days! So that the paint does not just dry, but hardens. After that, take a rag and rub the part. You can add a little oil.

#9 WhiteRus

• Voronezh city
  SOGMP

  I wonder if “clover” or some other inexpensive drug will turn him off?

  #10 Vyazemsky

• User
• 111 messages

• City: Kaliningrad

#11 Arthur

• City: Chelyabin

Blued MP-40 from Denix / pre-sanded and degreased / with Aiuminum Biack Metal Finish

The bluing turned out to be a well-saturated black color. It wore off in 1.5 years. Cheaper and better to paint, there is a post above.

#12 WhiteRus

• Voronezh city
  SOGMP

  Blued MP-40 from Denix / pre-sanded and degreased / with Aiuminum Biack Metal Finish

  The bluing turned out to be a well-saturated black color. It wore off in 1.5 years. Cheaper and better to paint, there is a post above.

  Those. Let’s apply the finish directly to the “bare” metal, and it will be the black color of the desired blued look?

  #13 Igor2000

• User
• 1,010 messages

• City: St. Petersburg
• 4th.ID

Yes, only right away until the metal oxidizes. Well, as was said above, such “blueing” is quickly erased. Then it will be necessary to repeat it periodically.

#14 WhiteRus

• Voronezh city
  SOGMP

  First I’ll cut off a piece from the long magazine (making it short, according to Feng Shui). And I will experiment. The topic with bleach really intrigued me)))

  Then I heat it with a burner and into oil. If there is no effect, I’ll buy this Amer’s gun)))

  #15 IGORIANGRAY

• User
• 491 messages

• Rostov-on-Don
  Azov Red Navy

  Post edited by IGORIANGRAY: 04 March 2016 - 13:28

  #16 WhiteRus

• User
• 1,427 messages

• Voronezh city
  SOGMP

  Aluminum is an intermediate metal, so doing something “quickly” after degreasing (again, depending on what) to prevent the surface from oxidizing will not work. Interacting with chlorine is an option, but most likely you need ferric chloride. The solution is made by mixing with water in equal parts. This is a cheaper but effective option. The most realistic and expensive one is anodizing. Therefore, in your case, don’t bother, just paint it with matte black enamel, using a regular aerosol can. But pre-degreasing is necessary (alcohol is best

  Degrease with alcohol? Monsters!

  Ferric chloride (in many sources) gives a dark gray color. And I just want to get rid of him. Initially, the device was painted by cross-eyed people in a dark gray, miserable look ((((

  #17 Gard

• User
• 221 messages

• Moscow city
• 421.FGTr./501.IR

Blued MP-40 from Denix / pre-sanded and degreased / with Aiuminum Biack Metal Finish

The bluing turned out to be a well-saturated black color. It wore off in 1.5 years. Cheaper and better to paint, there is a post above.

The same, the same and the same blued. He set up a whole chemical laboratory at home. Everything is well coated, it can be wiped off with difficulty, in the “regular” places!

#18 bim6

• Moscow city

Anything is possible, but the process will be difficult.

We deposit copper electrolytically.

We deposit iron on copper.

And the iron is brilliantly blued with the same clover, etc.

#19 Hans Lehmann

• City: Königsberg
• FRONTKJEMPER

I couldn’t bury the original aluminum support rail on the MP with anything. I just painted it with matte black paint and made it look a little old. Poor. I removed and installed the original unpainted one, I like it better. The post from bim6 will probably be the most optimal for silumin.

#20 komdiv Wolf

• Moscow city

I blued the src TT. First, I removed the paint with the cheapest remover from auto parts (in the form of an aerosol, I don’t remember the name). After coating with remover, the paint comes off in flakes; after wiping with a rag, the metal is clean. The only caveat is that it is better to carry out this work outside, the wash is very toxic.

At first I tried to blue the frame with clover; the frame sucks, but the blueing doesn’t give a damn, there’s no trace at all. Then I bought Aluminum
Black.
Now things have become more cheerful with her. True, it still blued slowly; it was necessary to apply the composition several times, but the required appearance was achieved. The coating turned out to be quite natural, but not very durable. The pistol quickly acquired a shabby, entourage look (worn like a combat pistol on the edges). However, over the course of a year, the coating retained a completely acceptable appearance.

Post edited by komdiv Wolf: 05 March 2016 - 23:11

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About copper plating

A galvanic method is provided for surface painting. Thanks to the copper layer, the product will be more attractive in appearance. This explains why copper plating is used predominantly in design projects. In addition, the copper layer provides the metal with high electrical conductivity. Copper plating can be the main process, the task of which is to create a surface layer. This galvanic method is also used as an intermediate operation when it is necessary to apply another metal layer to the surface. For example, if you need to perform silver plating, chrome plating and nickel plating.

What will you need for work?

According to experts, you can blacken aluminum using this method at home. However, first you need to acquire the necessary equipment and materials. First of all, prepare a source of electric current. A KBS-L battery rated at 4.5 volts is quite suitable for this purpose. Some craftsmen recommend 9-volt Krona batteries. You can also use a car battery or a low-power 12-volt rectifier.

To be able to regulate and smoothly stop the process, you will need a rheostat. The electrolyte solution will be contained in a neutral glass container or wide plastic container. It will be possible to supply current to the solution through anodes.

How to prepare the solution?

For high-quality electroplating you need to stock up on the following chemicals:

• Copper sulfate. 20 g will be enough.
• Hydrochloric or sulfuric acid (2-3 ml).

To prepare an electrolyte solution, these substances are dissolved in distilled water. Experts advise using at least 1 liter. Read more about how to blacken aluminum with copper sulfate at home.

Process description

Judging by the reviews, the procedure will go without problems if you follow the following sequence of actions. First of all, the part is cleaned and degreased. Then the product must be lowered into an empty container. Now you can connect the negative terminal to the aluminum. An electrolyte solution is prepared in a separate container. Next, the insulation is removed from one end of the stranded copper wire. It should look like a brush.

The other end of the wire is connected to the positive terminal. The blackening procedure consists of moistening the brush in the prepared solution and passing it over its surface without touching the workpiece. Finally, the aluminum product is washed and dried.

Source

Aluminum anodizing

Recently, structures and products made from anodized (abbreviated as anod.) aluminum profiles are increasingly in demand. Due to their beautiful appearance and benefits, anodized aluminum products are used in various fields of design and construction.

The oxide (anodic) film cannot protect the metal from the destructive effects of corrosion due to its large porosity, small thickness and low mechanical strength.

The most proven and reliable method of protecting metal and its alloys from harmful corrosion is the process of anodic oxidation in sulfuric acid solutions. This process is also called aluminum anodizing. The oxide layer, which is obtained by electrolytic method, has a density 200-2000 times greater than that of natural oxide films. Compared to other coating methods (varnishing, painting, covering the surface with polymer films), anodizing aluminum in black or any other color eliminates the problems of peeling and under-film corrosion.

Methods for removing carbon deposits from aluminum

Carbon deposits are a common phenomenon for aluminum cookware. Removing the remains of burnt food and returning the product to its natural shine and cleanliness is quite difficult, given the softness and capriciousness of the metal. However, it is possible to cope with the problem using available means and small tricks.

Dentifrice

To remove carbon deposits from the bottom of the pan, sprinkle it generously with tooth powder and sprinkle with a little water. Leave the container like this overnight, and in the morning remove dirt with a silicone spatula or soft sponge.

Laundry soap and vinegar

To clean carbon deposits, use the following effective method:

PVA and soap

Method for removing serious contaminants:

Other methods of dealing with soot

To remove minor stains, use one of the following methods:

Anodizing of parts

During the anodizing process, specialists perform preliminary mechanical processing of the aluminum profile, during which pressing defects are smoothed out (including scratches, stripes, scratches) and a matte, uniform surface is obtained.

Depending on the required surface quality of the finished metal parts, they are processed with a stream of shot or brushes made of stainless steel (grinding). In the first case, a more uniform and matte surface is obtained, in the second, the effect of a “combed” coating is achieved.

During treatment in a degreasing bath, surface contamination of the metal profile, oils and fats are eliminated.

From the profile surface during processing in an etching bath:

• aluminum oxide, which was formed under the natural influence of the environment, is removed
• foci of corrosion in the initial stage and small abrasions are etched off

As a result of anodization, optical alignment of the metal surface is achieved.

After etching in a clarification bath, all surface sludge is removed. The surface is now ready for oxidation (or anodizing process).

Then, under the influence of current (electric), a regular anode is grown. film, the thickness of which is 15-20 microns. The film grows inward and on the surface. This ensures corrosion protection and durability of the coating.

Grown anode. the film has a porous structure. It becomes hard after passing through a compaction bath containing hot water: the pores close.

To create a high-quality color film (color anodizing), before the seal bath, the aluminum profile is passed through a dye bath. The result is a porous anode. the whip acquires the required color.

Various requirements are imposed on the final quality of the processed surface of the profile, therefore the following is done:

• oxidation without mechanical treatment
• oxidation with mechanical treatment

When aluminum is anodized without pre-treatment, aesthetic requirements for the surface are achieved using chemical methods. Oxidation with mechanical processing allows you to obtain high-quality special effects on the surface of a metal profile.

Oxidation. Oxidation process. Aluminum oxidation.

What is Oxidation?! Thermal oxidation.

We already know that some oxide films formed as a result of corrosion prevent further destruction of the metal. Metals that are easily subject to corrosion destruction: aluminum, magnesium and zinc are resistant to atmospheric conditions, since due to easy oxidation, a strong oxide film is formed on their surface. Taking advantage of these properties of oxide films, artificial oxide films are often created, this is called oxidation . It is widely used to protect firearms, machine tools, various devices, etc. With this coating, the parts acquire a characteristic black or blue color. Products made of iron, steel, aluminum and its alloys are usually subjected to oxidation.

There are two ways to oxidize steel parts:

— Wet ( chemical oxidation );

— Dry ( thermal oxidation ).

Chemical oxidation. Oxidation solution.

The most common chemical method for obtaining a protective film on products made from iron. Chemical oxidation is carried out in alkali solutions to which nitrate and nitrate salts of alkali metals are added.

Precautionary measures

To work with molten aluminum, you must use personal protective equipment. All exposed areas of the body, hands, and face must be protected.

REFERENCE! It is best to use welding gloves; they can withstand temperatures of more than 600 0 C. This means of protection is the most basic, since the possibility of molten metal getting on your hands is very high.

It is also better to use goggles and a mask to avoid hot elements coming into contact with your face and eyes. To protect the entire body, you can find a metallurgist suit that has high fire resistance. When cleaning aluminum welding flux, a chemical respirator is used.

Aluminum blackening method

#1 NetSkater

A question the answer to which will be of interest to many DIYers - how to blacken aluminum? Requirements: 1. Durability of the blackening - so that it does not peel off from minor scratches. The autonitro paint doesn’t fit, it peels off. 2. Do not wipe it with your hands or detergents for optics (alcohol, gasoline). Painting over it with a marker is also not suitable. 3. To have a smooth black matte surface. 4. To simply apply - anodizing and various complex chemistry, for which you have to run halfway across the city - is also not very special..

Maybe there are ready-made chemical compositions, such as gel for bluing steel - all sorts of Liquid Blue (but only for aluminum)? Please advise.

#2 Guest_Not the Hermitage_*

1) Our company offers a number of services, including anodizing of aluminum parts prone to oxidation in air. Our partners and clients have become agricultural enterprises and automobile factories, food industry enterprises and advertising firms, trading organizations and construction companies, as well as just PEOPLE from housewives and fishermen to ultralight aviation enthusiasts. +7 Moscow, st. Klara Zetkin, 29 https://www.intormetall.ru/ https://www.intormetall.ru/prof6/1/

Blackening of aluminum radiators. To increase the heat transfer efficiency of the radiator, its surface is usually made matte and dark. An accessible method of blackening is treating the radiator in an aqueous solution of ferric chloride. To prepare the solution, an equal volume of ferric chloride powder and water is required. The radiator is cleaned of dust and dirt, thoroughly degreased with gasoline or acetone and immersed in the solution. Keep in the solution for 5-10 minutes. The color of the radiator is dark gray. Processing must be done in a well-ventilated area or outdoors.

2) ANODIZATION OF ALUMINUM AND ITS ALLOYS Parts and products made of aluminum and its alloys oxidize in air, resulting in the formation of gray spots on the surface that spoil the appearance.

Duralumin (aluminum) becomes more beautiful if it is anodized, which results in the formation of a thin passive layer on the surface that prevents further oxidation.

The anodized surface has a pleasant gray color. In addition, after anodizing, the aluminum product can be easily painted in any color using conventional aniline dyes.

First, prepare separately two saturated solutions - baking soda and table salt - in boiled water at room temperature. To obtain a saturated solution, dissolution must be carried out for at least half an hour, stirring the solution periodically. After this, the solutions must stand for 15 minutes and must be filtered. Then prepare the electrolyte by mixing nine parts by volume of a baking soda solution and one part by volume of a salt solution (9:1). The electrolyte is mixed well in a glass container. Before anodizing, the part is thoroughly cleaned with fine sandpaper, degreased (can be in a hot solution of washing powder) and washed in running water, after which it should not be touched with hands. Then the part to be anodized is immersed in an electrolyte solution, which should be in an aluminum container. As a current source, you can use an adjustable rectifier with a voltage of 12 V and a current of up to 2 A or a car battery. The “plus” of the current source is connected to the part, the “minus” is connected to an aluminum container with electrolyte. The current density should be about 15 mA/cm2. To fulfill this condition, the required current density must be multiplied by the surface area of ​​the part in square centimeters. The current value calculated in this way is maintained by adjusting the current source. Anodizing lasts about 90 minutes until the part is covered with a bluish-gray coating. The anodizing process can be observed by the release of air bubbles and the appearance of a light gray coating on the surface of the anodized part. After anodizing is completed, the part is washed in running water and cleaned from electrochemical reaction products with a cotton swab dipped in a solution of potassium permanganate. After this, the surface of the part becomes smooth, with a light gray tint. The part is washed again in running water and dried in air. If desired, the part after anodizing can be painted in a solution of aniline dye. The dye solution contains 15 g of dye and 1 ml of acetic acid per 1 liter of water. Coloring is carried out in a solution heated to 60.80°C. The duration of exposure in the solution depends on the required color saturation and is usually 10.15 minutes. To fix the color, the painted part is kept in boiling distilled water for 1.1.5 minutes. To protect the part from mechanical damage, it is useful to paint it with colorless furniture varnish (NC).

Details

Technological process - video instructions

A refractory container (crucible) is used to heat the metal. Products are used from materials such as steel, porcelain, corundum, cast iron. At home, a container made of a wide iron pipe or a ready-made crucible is used. To make it, you only need a grinder and a welding machine. The volume of the crucible can be different and is selected individually; it heats up evenly. The metal must be crushed and melted during heat transfer.

The melting point must be reduced before heat treatment in order for the state of the metal to change more quickly. To do this, it is crushed into small parts. This is often followed by oxidation or combustion. Aluminum oxide is formed, which changes its state at higher temperatures. This substance is removed after remelting the metal along with the rest of the slag.

REFERENCE! When melting aluminum at home, you must avoid getting liquid into the crucible. This is because the evaporation of water can cause an explosion. Therefore, before lowering the metal into the crucible, you need to make sure it is completely dry.

Mostly aluminum wire is melted. To do this, it is divided into pieces with scissors, and then compressed with pliers. This method prevents the metal from being exposed to oxygen. If you do not plan to obtain high-quality parts, then grinding raw materials is not necessary.

If you need to produce molten aluminum at home, you will have to model the casting technology yourself. The material must first be cleaned of dirt, slag and impurities. Large workpieces must be divided into several small ones. Casting is carried out according to the instructions; the most convenient option is used for melting. Slag must be removed from the surface of the fluid substance. Molten aluminum is poured into a mold, which must be broken after the metal has solidified.

Heat sources used

In order to melt aluminum at home, you can use:

1. Melting aluminum in a muffle furnace, which can be done independently. This method is very effective and allows you to quickly convert the metal into liquid form.
2. Blowtorch. It can be used to melt small amounts of aluminum.
3. Torch - rarely used.

The hearth is made of bricks, and the frame is made of a metal container. On one side, a drill is used to make a hole for oxygen supply. A hair dryer, vacuum cleaner or other similar device is connected to a metal tube. The crucible is placed in the hearth after the fire has been lit. For better heat treatment, the coals can also be placed on the sides. To avoid losing heat, you can make a lid, leaving a hole for the smoke to escape. It is not worth making a furnace if the metal needs to be melted only once.

Melting aluminum on a gas stove also takes place. An ordinary gas stove can heat metal to the required temperature. Small pieces of aluminum will melt in about half an hour.

A tin can is usually used as a crucible. The jar is placed in another jar so that the gap between the two is about one centimeter. This is necessary for uniform temperature distribution. In the larger jar, you need to make several holes to provide fire access. The diameter of these holes should be 3-4 cm in diameter. In this case, the divider on the burner does not need to be removed. In this way, you can achieve uniform heating of the aluminum can. The larger jar is covered with a lid to prevent heat from escaping.

Making a mold for casting - instructions

If you need to do something simple, then making a special mold is not required; the metal can be poured onto a steel sheet.

If the product is more complex, then you need a mold that can be made from the following materials:

• - clay;
• - plaster;
• - liquid glass;
• - sand;
• - coal ash.

There are two ways to pour the alloy into a mold - open and closed.

Open is the easy way. The metal that has been melted is poured into an ordinary container, cup, tin can, and so on. After the alloy has cooled, the blank is removed from the container. If it doesn't matter what shape the metal object will be, leave the aluminum on a durable surface.