Ways to restore rusty iron. How to restore any rusty old tool in "ideal Product data nanoprotech universal

Corrosion is the main enemy of everything that is metal - from the fence to the car body. The fact is that the corrosive process is irreversible, irrevocably destroying metal products. Therefore, it is so important to “intervene” in this process and stop it, which can be done with the help of a rust remover, or, as it is also called, a “rust converter”.

What is rust remover

Rust remover - a concentrate of chemically active substances that stop the rusting of the metal and protect its surface from corrosion.

The basis of this product is orthophosphoric (phosphoric) acid (up to 48% depending on the brand of the manufacturer). In addition, inhibitors are introduced into the product for more comfortable work with the drug, because, as you know, this acid can burn the skin and destroy teeth.

Rust converter functions:

• "Eating" corrosion products and stopping the subsequent rusting of the metal.
• Removes acid stains from products and coatings made of copper, brass, aluminum and other types of metal.
• Restores the porous surface of corroded metal.
• Well wets the metal surface.
• Improves adhesion of primer and other coatings after treatment.

The concentrate is highly soluble in water, so it can be diluted to the desired state. For example, if the rust on the surface is negligible, you should not use the product in a concentrated state.

How to use rust remover

Depending on the degree of rust and the type of metal to be cleaned, the rust remover is used in different concentrations. The exposure time of the preparation applied to the scale also differs.

1. Purification of ferruginous metals severely damaged by corrosion.

To remove a thick layer of rust, you need to take part of the concentrate and dilute it in three parts of water. Mix thoroughly and apply with a stiff brush to damaged metal or lower metal products with scale into the resulting solution. The exposure time in both cases is from 25 minutes to an hour.

After the time has elapsed, the cleaned surfaces and products must be thoroughly rinsed with water and dried completely. For a better effect, you can cover the treated surfaces with a moisture-displacing composition.

1. Cleaning of non-ferrous metals, severely damaged by corrosion.

To remove rust from non-ferrous metals, it is necessary to prepare a solution of rust remover and water in a ratio of 1/7 or 1/10, depending on the degree of damage to the metal by scale.

Thoroughly treat products and surfaces with the finished solution, leaving the product to act for 20-60 minutes. Then rinse thoroughly clean water treated surfaces and allow to dry completely.

1. Purification of ferruginous metals slightly damaged by corrosion.

In this case, the solution is prepared in the following proportion: one part of the concentrate to 15-20 parts of water. Thoroughly mix and treat rusty items and metal surfaces. Leave to act for up to 40 minutes.

To speed up the process of cleaning metal from rust, the solution can be heated to 60 degrees, then apply it for its intended purpose and wait half the standard exposure time.

At the end of the procedure, wash the products and surfaces with water, dry thoroughly and treat with a water-repellent composition.

In every house, among household utensils, interior items, there are materials, tools or parts made of metal. They are practical, wear-resistant, but sooner or later they corrode. How to prevent this process? How to treat metal so that it does not rust?

There are several methods that allow you to extend the life of iron parts and objects. The most effective way is chemical treatment. These include inhibitor compounds that coat metal objects with a thin film. It is she who allows you to protect the product from destruction. Such drugs are often used for preventive purposes.

Consider the main methods to prevent corrosion:

• mechanical removal of rust;
• chemical treatment;
• anti-corrosion agents;
• folk remedies for rust.

mechanical cleaning

To perform mechanical treatment against corrosion manually, it is necessary to purchase a metal brush or coarse abrasive paper. Items can be processed dry or wet way. In the first version, the usual scraping of rust occurs, and in the second, the skin is wetted in a solution of white spirit or kerosene.

It is also possible to carry out mechanical cleaning of rusting materials using hardware, such as:

• Bulgarian.

• Sander.

• Electric drill with a metal brush attachment.

• Sandblasting machine.

Undoubtedly, manually you can clean the surface more thoroughly. But it is used in small areas. Hardware materials will speed up the workflow, but they can also harm details. During processing, a large layer of metal will be removed. Most best option which gently removes corrosion - sandblasting machine. Such equipment has its own small drawback - high cost.

When processing objects with sandblasting equipment, the metal surface does not grind off, but retains its structure. A powerful sand jet gently removes rust.

Chemical treatment

Chemicals are divided into two groups:

• Acids (the most popular orthophosphoric);
• Rust converters.

Acids are often used to mean common solvents. Some of them have an orthophosphorus composition, which allows you to restore rusting material. The way to use the acid is quite simple: wipe the iron or metal from dust with a damp cloth, then remove the remaining moisture, apply a thin layer of acid with a silicone brush on the object.

The substance will react with the damaged surface, leave it for 30 minutes. When the part is cleaned, wipe the treated area with a dry cloth. Before use chemicals put on overalls from rust. In the course of work, take care that the composition does not get on your exposed skin.

Orthophosphoric acid has a number of advantages over other compounds. It gently acts on metal objects, removes rust and prevents the appearance of new areas of infection.

Rust converters are applied to the entire metal surface, thus forming a protective layer that will further prevent corrosion of the entire object. After the composition dries, you can open it with paint or varnish. Today, a large number of converters are produced in the construction industry, the most popular of them are:

• Rust modifier Berner. Designed for processing bolts and nuts that cannot be dismantled.

• Rust neutralizer VSN-1. Used in small areas. Neutralizes rusty spots, forming a gray film that can be easily wiped off with a dry cloth.

• Aerosol "Zincor". The degreasing composition allows you to restore objects that are in rust, forms a protective film on the surface.

• It is a fast acting gel that does not run and removes any type of corrosion.

• Converter SF-1. Used for cast iron, galvanized, aluminum surfaces. Removes rust, protects the material after processing, extends its service life up to 10 years.

Most of the anti-corrosion agents consist of toxic chemical compounds. Make sure you have a respirator. So you protect the mucous membrane of the respiratory tract from irritation.

The use of anti-corrosion compounds

Rocket Chemical, one of the leading chemical companies, offers a wide range of anti-corrosion products. But the most effective is a line of five substances:

• long acting inhibitor. Treated metal products may be all year round on the street. At the same time, they are protected from any weather influences that provoke a corrosive process.

• Protective lithium grease. The material is applied to the surface to protect and prevent rusting. It is recommended for application to door hinges, chains, cables, rack and pinion mechanisms. Forms a protective film that is not washed off by precipitation.

• Waterproof silicone grease. Due to its silicone composition, the lubricant is applied to metal surfaces with elements of plastic, vinyl and rubber. Dries quickly to form a thin, sheer, non-tacky finish.

• Rust spray. The drug is used to treat hard-to-reach places, designed for deep penetration, protects products from the reappearance of rust. Widely used for processing threaded connections and bolts from corrosion.

• A solution that removes corrosive stains. The composition of the solution includes non-toxic substances. It can be used for processing building materials and various kitchen utensils. How to make a knife not rust? Feel free to process it with a solution, leave it for 5 hours, then wash it well with a detergent. And the knife is ready for use again.

In the video: rust destroyer WD-40.

Folk remedies

What to do if chemicals Allergy, and rust from metal objects should be cleaned? Don't despair, there are many folk remedies, which are in no way inferior to factory preparations:

• Cilit is a cleaner for plaque and rust in the bathroom and kitchen. This gel is often applied to faucets, faucets, if the knife is rusting or other metal appliances. It is also used to remove corrosion from any iron and metal products. But it should be remembered that it chemical composition may corrode the paint.
• A solution of kerosene and paraffin. It must be prepared in a ratio of 10:1. Leave to brew for a day. After we process the objects damaged by rust, leave for 12 hours. Finally, clean the treated area with a dry cloth. This method is suitable for building materials and tools.
• Coca Cola against rust. Its alkaline composition corrodes corrosive stains. To do this, immerse the item in a container with a drink or dampen a rag. Leave for a day, then rinse the item under running water.

As you can see, nothing is impossible. Therefore, choose a more acceptable option for yourself in order to return the original look to metal products.

Top 5 Ways to Remove Rust (1 video)

In connection with the appearance of a certain gas, causing an instant burning cough. This article is the identification of this gas. The article is replete with formulas; the number of formulas is due to the non-triviality of both the electrolysis process itself and the rust itself. Chemists and chemists, help bring the article to full compliance with reality; it is your duty to take care of the "little" brothers in the event of a chemical hazard.

Let there be iron Fe 0:
- if there was no water on Earth, then oxygen would fly in - and made oxide: 2Fe + O 2 \u003d 2FeO (black). The oxide oxidizes further: 4FeO + O 2 = 2Fe 2 O 3 (red-brown). FeO 2 does not exist, these are schoolchildren's inventions; but Fe 3 O 4 (black) is quite real, but artificial: supplying superheated steam to iron or reducing Fe 2 O 3 with hydrogen at a temperature of about 600 degrees;
- but there is water on Earth - as a result, both iron and iron oxides tend to turn into the base Fe (OH) 2 (white ?!. It quickly darkens in the air - is it not a point below): 2Fe + 2H 2 O + O 2 \u003d 2Fe(OH) 2 , 2FeO + H 2 O = 2Fe(OH) 2 ;
- further even worse: there is electricity on Earth - all these substances tend to turn into the base Fe (OH) 3 (brown) due to the presence of moisture and potential difference (galvanic couple). 8Fe(OH) 2 + 4H 2 O + 2O 2 = 8Fe(OH) 3 , Fe 2 O 3 + 3H 2 O = 2Fe(OH) 3 (slowly). That is, if iron is stored in a dry apartment, it rusts slowly, but holds on; increase the humidity or wet it - it will become worse, and stick it into the ground - it will be very bad.

Preparing a solution for electrolysis is also an interesting process:
- first, the analysis of the available substances for the preparation of solutions is carried out. Why soda ash and water? Soda ash Na 2 CO 3 contains Na metal, which is much to the left of hydrogen in a number of electrical potentials - which means that during electrolysis the metal will not be reduced at the cathode (in solution, but not in melt), and water will decompose into hydrogen and oxygen (in solution). There are only 3 variants of the reaction of the solution: metals much to the left of hydrogen are not reduced, weakly to the left of hydrogen they are reduced with the release of H 2 and O 2, to the right of hydrogen they are simply reduced at the cathode. Here it is, the process of copper plating of the surface of parts in a CuSo 4 solution, galvanizing in ZnCl 2, nickel plating in NiSO 4 + NiCl 2, etc.;
- to dilute soda ash in water stands in calm, slowly and without breathing. Do not tear the package with your hands, but cut it with scissors. After that, the scissors must be put in the water. Any of the four types of soda (food, soda, washing, caustic soda) takes moisture from the air; its shelf life, in fact, is determined by the time of accumulation of moisture and clumping. That is, in glass jar shelf life - eternity. Also, any soda generates a sodium hydroxide solution when mixed with water and electrolysis, differing only in the concentration of NaOH;
- soda ash is mixed with water, the solution becomes bluish in color. It would seem that a chemical reaction has taken place - but not: as in the case of table salt and water, the solution does not have a chemical reaction, but only a physical one: the dissolution of a solid in a liquid solvent (water). You can drink this solution and get mild to moderate poisoning - nothing fatal. Or evaporate and get soda ash back.

The choice of anode and cathode is a whole undertaking:
- it is advisable to choose the anode as a solid inert material (so that it does not collapse, including from oxygen, and does not participate in chemical reactions) - that is why stainless steel acts as it (I read heresy on the Internet, I almost got poisoned);
- it is pure iron that is the cathode, otherwise rust will act as an excessively high resistance electrical circuit. To place the iron to be purified completely into the solution, you need to solder or screw it to some other iron. Otherwise, the metal of the iron holder itself will take part in the solution as a non-inert material and as a section of the circuit with the least resistance (parallel connection of metals);
- not yet specified, but there should be a dependence of the flowing current and electrolysis rate on the surface area of ​​the anode and cathode. That is, one M5x30 stainless steel bolt may not be enough for fast withdrawal rust from the car door (to realize the full potential of electrolysis).

Let's take an inert anode and cathode as an example: considering the electrolysis of only a blue solution. As soon as voltage is applied, the solution begins to transform to the final one: Na 2 CO 3 + 4H 2 O \u003d 2NaOH + H 2 CO 3 + 2H 2 + O 2. NaOH - sodium hydroxide - mad alkali, caustic soda, Freddy Krueger in a nightmare: the slightest contact of this dry substance with wet surfaces (skin, lungs, eyes, etc.) causes hellish pain and fast irreversible (but recoverable with a mild degree of burn ) damage. Fortunately, sodium hydroxide is dissolved in carbonic acid H 2 CO 3 and water; when the water is finally evaporated by hydrogen at the cathode and oxygen at the anode, the maximum concentration of NaOH in carbonic acid is formed. It is absolutely impossible to drink or smell this solution, it is also impossible to poke your fingers (the longer the electrolysis, the more it burns). You can clean the pipes with it, while understanding its high chemical activity: if the pipes are plastic, you can hold them for 2 hours, but if they are metal (grounded, by the way) - the pipes will start to eat: Fe + 2NaOH + 2H 2 O \u003d Na 2 + H 2 , Fe + H 2 CO 3 \u003d FeCO 3 + H 2.

This is the first of possible causes suffocating "gas", physical and chemical process: saturation of air with a solution of concentrated sodium hydroxide in carbonic acid (boiling bubbles of oxygen and hydrogen as carriers). In the books of the 19th century, carbonic acid is used as a poisonous substance (in large quantities). That is why drivers who install batteries in the car get damaged by sulfuric acid (in fact, the same electrolysis): in the process of overcurrent to a highly discharged battery (the car has no current limit), the electrolyte boils for a short time, sulfuric acid comes out together with oxygen and hydrogen in the cabin. If the room is made completely airtight, due to the oxygen-hydrogen mixture (explosive gas), you can get a good blow with the destruction of the room. The video shows broads in miniature: under the action of molten copper, water decomposes into hydrogen and oxygen, and metal is more than 1100 degrees (I can imagine how the room completely filled with it stinks) ... About the symptoms of NaOH inhalation: caustic, burning sensation, sore throat, cough, shortness of breath, shortness of breath ; symptoms may be delayed. Feels like it fits perfectly.
...at the same time, Vladimir Vernadsky writes that life on Earth without carbonic acid dissolved in water is impossible.

We replace the cathode with a rusty piece of iron. A whole series of funny chemical reactions begins (and here it is, borscht!):
- rust Fe (OH) 3 and Fe (OH) 2, as bases, begin to react with carbonic acid (released at the cathode), obtaining siderite (red-brown): 2Fe (OH) 3 + 3H 2 CO 3 \u003d 6H 2 O + Fe 2 (CO3) 3, Fe (OH) 2 + H 2 CO 3 \u003d FeCO 3 + 2 (H 2 O). Iron oxides do not participate in the reaction with carbonic acid, because. there is no strong heating, and the acid is weak. Also, electrolysis does not restore iron at the cathode, because. these bases are not a solution, but the anode is not iron;
- caustic soda, as a base, does not react with bases. Necessary conditions for Fe(OH) 2 (amphoteric hydroxide): NaOH>50% + boiling in nitrogen atmosphere (Fe(OH) 2 + 2NaOH = Na2). Necessary conditions for Fe (OH) 3 (amphoteric hydroxide): fusion (Fe (OH) 3 + NaOH \u003d NaFeO 2 + 2H 2 O). Necessary conditions for FeO: 400-500 degrees (FeO + 4NaOH \u003d 2H 2 O + Na 4 FeO 3). Or maybe there is a reaction with FeO? FeO + 4NaOH = Na 4 FeO 3 + 2H 2 O - but only at a temperature of 400-500 degrees. Okay, maybe the sodium hydroxide removes some of the iron - and the rust just falls off? But here is a bummer: Fe + 2NaOH + 2H 2 O \u003d Na 2 + H 2 - but when boiling in a nitrogen atmosphere. What the hell is a solution of caustic soda without electrolysis removes rust? But he does not remove it in any way (I poured out exactly a transparent solution of caustic soda from "Auchan"). It removes grease, and in my case, with a piece of matiz, it dissolved the paint and primer (the resistance of the primer to NaOH is in its performance characteristics) - which exposed a clean iron surface, the rust simply disappeared. Conclusion: soda ash is needed only to obtain acid by electrolysis, which cleans the metal, taking rust on itself at an accelerated pace; sodium hydroxide seems to be out of business (but will react with debris in the cathode, cleaning it).

About foreign substances after electrolysis:
- the solution changed its color, became "dirty": with reacted bases Fe(OH) 3 , Fe(OH) 2 ;
- black plaque on the gland. First thought: iron carbide Fe 3 C (triiron carbide, cementite), insoluble in acids and oxygen. But the conditions are not the same: to obtain it, you need to apply a temperature of 2000 degrees; and in chemical reactions there is no free carbon to attach to iron. The second thought: one of the iron hydrides (saturation of iron with hydrogen) - but this is also not true: the conditions for obtaining are not the same. And then it came up: iron oxide FeO, the basic oxide does not react with either acid or caustic soda; and also Fe 2 O 3 . And amphoteric hydroxides are layers above the basic oxides, protecting the metal from further penetration of oxygen (they do not dissolve in water, they prevent the access of water and air to FeO). You can put the cleaned parts in citric acid: Fe 2 O 3 + C 6 H 8 O 7 \u003d 2FeO + 6CO + 2H 2 O + 2H 2 ( Special attention on the release of carbon monoxide and on the fact that acid and metal eat on contact) - and FeO is removed with an ordinary brush. And if you heat the highest oxide in carbon monoxide and do not burn out, then it will restore iron: Fe 2 O 3 + 3CO \u003d 2Fe + 3CO 2;
- white flakes in solution: some salts that are insoluble during electrolysis either in water or in acid;
- other substances: iron is initially "dirty", water is not initially distilled, dissolution of the anode.

The second of the possible causes of suffocating "gas" is a physical and chemical process: iron, as a rule, is not pure - with galvanization, primer and other third-party substances; and water - with minerals, sulfates, etc. Their reaction during electrolysis is unpredictable, anything can be released into the air. However, my piece was so small (0.5x100x5) and the tap water (weakly mineralized) is unlikely to be the cause. Also, the idea of ​​the presence of foreign substances in the soda ash itself has disappeared: only it is indicated on the packaging in the composition.

The third possible cause of asphyxiating gas is a chemical process. If the cathode is restored, then the anode is bound to be destroyed by oxidation, if not inert. Stainless steel contains about 18% chromium. And this chromium, when destroyed, enters the air in the form of hexavalent chromium or its oxide (CrO 3 , chromic anhydride, reddish - further we will talk about it), a strong poison and a carcinogen with a delayed catalysis of lung cancer. The lethal dose is 0.08g/kg. Ignites gasoline at room temperature. Released when welding stainless steel. The horror is that it has the same symptoms as sodium hydroxide when inhaled; and sodium hydroxide already seems like a harmless animal. Judging by the description of cases of at least bronchial asthma, you need to work as a roofer for 9 years, breathing this poison; however, a clear delayed effect is described - that is, it can shoot both 5 and 15 years after a single poisoning.

How to check if chrome stood out from stainless steel (where - the question remains). The bolt after the reaction became more shiny than the same bolt from the same batch - a bad sign. As it turned out, stainless steel is such as long as chromium oxide exists in the form protective coating. If chromium oxide was destroyed by oxidation during electrolysis, then such a bolt will rust more intensively (free iron will react, and then chromium in the composition of untouched stainless steel will oxidize to CrO). Therefore, he created all the conditions for the rusting of two bolts: salt water and a solution temperature of 60-80 degrees. Stainless steel grade A2 12X18H9 (X18H9): it contains 17-19% chromium (and in stainless iron-nickel alloys, chromium is even higher, up to ~ 35%). One of the bolts turned red in several places, all places - in the contact zone of the stainless steel with the solution! The reddest one is along the line of contact with the solution.

And my happiness was that the current strength was then only 0.15A during electrolysis, the kitchen was closed and the window in it was open. It was clearly imprinted in my mind: to exclude stainless steel from electrolysis or to do it in an open area and at a distance (there is no stainless steel without chromium, this is its alloying element). Because stainless steel is NOT an inert anode during electrolysis: it dissolves and releases poisonous chromium oxide; sofa chemists, kill yourself against the wall until someone dies from your advice! The question remains, in what form, how much and where; but taking into account the release of pure oxygen at the anode, CrO is already precisely oxidized to the intermediate oxide Cr 3 O 2 (also poisonous, MPC 0.01 mg / m 3), and then to the higher oxide CrO 3: 2Cr 2 O 3 + 3O 2 \u003d 4CrO3. The latter remains an assumption (the necessary alkaline environment is present, but whether strong heating is needed for this reaction), but it is better to play it safe. Even blood and urine tests for chromium are difficult to do (they are not in the price lists, not even in the extended general blood test).

Inert electrode - graphite. It is necessary to go to the trolleybus depot, take pictures of the discarded brushes. Because even on aliexpress for 250 rubles per pin. And this is the cheapest of the inert electrodes.

And here is 1 more real example when the sofa electronics led to material losses. And to the right knowledge, really. As in this article. The benefits of sofa idle talk? - hardly, they sow chaos; and have to clean up after them.

I tend to the first reason for the suffocating "gas": the evaporation of a solution of sodium hydroxide in carbonic acid into the air. Because with chromium oxides, it is hose masks with mechanical air supply that are used - I would have suffocated in my miserable RPG-67, but it was noticeably easier to breathe in it at the very epicenter.
How to check for chromium oxide in the air? Start the process of water decomposition in a pure solution of soda ash on a graphite anode (pick out from a pencil, but not every pencil contains a pure graphite rod) and an iron cathode. And take a chance to inhale the air in the kitchen again after 2.5 hours. Is it logical? Almost: the symptoms of caustic soda and hexavalent chromium oxide are identical - the presence of caustic soda in the air will not prove the absence of hexavalent chromium vapor. However, the absence of odor without stainless steel will clearly give the result of the presence of hexavalent chromium. I checked, there was a smell - a phrase with hope "hooray! I breathed caustic soda, not hexavalent chromium!" can be broken into jokes.

What else was forgotten:
- how do acid and alkali exist together in one vessel? In theory, salt and water should appear. There is a very subtle point here, which can only be understood experimentally (did not check). If all the water is decomposed during electrolysis and the solution is isolated from salts in the precipitate - option 2: either a solution of caustic soda or caustic soda with carbonic acid will remain. If the latter is in the composition, the release of salt under normal conditions and the precipitation of ... soda ash will begin: 2NaOH + H 2 CO 3 \u003d Na 2 CO 3 + 2H 2 O. The problem is that it will dissolve in water right there - sorry, the taste cannot be tasted and compared with the original solution: suddenly the caustic soda has not completely reacted;
- Does carbonic acid interact with iron itself? The question is serious, because. the formation of carbonic acid occurs precisely at the cathode. You can check by creating a more concentrated solution and doing electrolysis until a thin piece of metal is completely dissolved (did not check). Electrolysis is seen as a more gentle rust removal method than acid pickling;
What are the symptoms of inhaling explosive gas? No + no smell, no color;
- Do caustic soda and carbonic acid react with plastic? Make identical electrolysis in plastic and glass containers and compare the turbidity of the solution and the transparency of the surface of the container (did not check on glass). Plastic - became less transparent in places of contact with the solution. However, these turned out to be salts, easily scraped off with a finger. So, food plastic does not react with the solution. Glass is used to store concentrated alkalis and acids.

If you inhale a lot of burning gas, regardless of whether it is NaOH or CrO 3, you need to take "unithiol" or a similar drug. And it works general rule: no matter what poisoning occurs, no matter what strength and origin it may be, drink plenty of water in the next 1-2 days, if the kidneys allow. Task: remove the toxin from the body, and if this is not done by vomiting or expectoration, give additional opportunities to do this to the liver and urinary system.

The most annoying thing is that this is all the 9th grade school curriculum. Damn, I'm 31 years old - and I won't pass the exam ...

Electrolysis is interesting in that it turns back time:
- a solution of NaOH and H 2 CO 3 under normal conditions will lead to the formation of soda ash, while electrolysis inverts this reaction;
- iron in natural conditions is oxidized, and is restored during electrolysis;
- hydrogen and oxygen tend to combine in any way: mix with air, burn and become water, absorb or react with something; electrolysis, on the contrary, generates gases of various substances in their pure form.
The local time machine, nothing else: returns the position of the molecules of substances to their original state.

According to the reaction formulas, a solution of powdered sodium hydroxide is more dangerous when it is created and electrolyzed, but more effective in certain situations:
- for inert electrodes: NaOH + 2H 2 O = NaOH + 2H 2 + O 2 (the solution is a source of pure hydrogen and oxygen without impurities);
- reacts more intensively with organic materials, there is no carbonic acid (fast and cheap degreaser);
- if iron is taken as an anode, it will begin to dissolve at the anode and be reduced at the cathode, thickening the iron layer on the cathode in the absence of carbonic acid. This is a method of restoring the cathode material or coating it with another metal when there is no solution with the desired metal at hand. Rust removal, according to experimenters, also goes faster if iron is made the anode in the case of soda ash;
- but the concentration of NaOH in the air during evaporation will be higher (you still need to decide which is more dangerous: carbonic acid with caustic soda or moisture with caustic soda).

Earlier I wrote about education that a lot of time is wasted in school and university. This article does not change this opinion, because an ordinary person will not need matan, organic chemistry or quantum physics in life (only at work, and when I needed matan 10 years later, I learned it again, I didn’t remember anything at all). But inorganic chemistry, electrical engineering, physical laws, Russian and foreign languages- this is what should be a priority (still introduce the psychology of the interaction of the sexes and the foundations of scientific atheism). Here, I did not study at the Faculty of Electronics; and then bam, locked up - and Visio learned to use, and MultiSim and some of the designations of the elements learned, etc. Even if I studied at the Faculty of Psychology, the result would be the same: I got stuck in life - bit into it - figured it out. But if at school the emphasis on natural sciences and languages ​​\u200b\u200bis been strengthened (and they explained to young people why it was strengthened), life would be easier. Both at school and at the institute in chemistry: they talked about electrolysis (theory without practice), but about the toxicity of vapors - no.

Finally, an example of obtaining pure gases (using inert electrodes): 2LiCl + 2H 2 O = H 2 + Cl 2 + 2LiOH. That is, first we poison ourselves with the purest chlorine, and then we explode with hydrogen (again, to the issue of the safety of the emitted substances). If there was a CuSO 4 solution, and the iron-metal cathode would drop out of the base and leave an oxygen-containing acid residue SO4 2-, it does not participate in the reactions. If the acid residue did not contain oxygen, it would decompose into simple substances (which is seen in the example of C 1 - , which is released as Cl 2).

(added 05/24/2016) If you need to boil NaOH with rust for their mutual reaction - why not? Nitrogen in the air is 80%. The effectiveness of rust removal will increase significantly, but then this process must definitely be done outdoors.

About metal hydrogenation (increase in brittleness): I did not find any formulas and adequate opinions on this topic. If possible, I will set up the electrolysis of the metal for several days, adding a reagent, and then I will knock with a hammer.

(added 05/27/2016) Graphite can be removed from a used salt battery. If it stubbornly resists disassembly, deform it in a vice.

(added 06/10/2016) Metal hydrogenation: H + + e - = H ads. H ads + H ads \u003d H 2, where ADS is adsorption. If the metal has necessary conditions dissolve hydrogen in itself (this is a number!) - then it dissolves it in itself. The conditions for the occurrence of iron have not been found, but for steel they are described in the book of Schrader A.V. "Influence of Hydrogen on Chemical and Petroleum Equipment". In Figure 58, page 108, there is a graph of the brand 12X18H10T: at a pressure comparable to atmospheric pressure and a temperature of 300-900 degrees: 30-68 cm 3 / kg. Figure 59 shows dependencies for other steel grades. The general formula for steel hydrogenation is: K s = K 0 e -∆H/2RT, where K 0 is the pre-exponential factor 1011l/mol s, ∆H is the heat of dissolution of steel ~1793K), R is the universal gas constant 8.3144598J/(mol ·K), T - medium temperature. As a result, at room temperature 300K we have K s = 843 l/mol. The number is not correct, you need to double-check the parameters.

(added 06/12/2016) If caustic soda does not interact with metals without high temperature, it is a safe (for metal) degreaser for pallets, pans and other things (iron, copper, stainless steel - but not aluminum, teflon, titanium, zinc).

With hydrogenation - clarifications. The pre-exponential factor K 0 lies in the range 2.75-1011l/mol·s, this is not a constant value. Calculating it for stainless steel: 10 13 C m 2/3, where C m is the atomic density of steel. The atomic density of stainless steel is 8 10 22 at / cm 3 - K 0 \u003d 37132710668902231139280610806.786 at. / cm 3 \u003d - and then everything is stuck.

If you look closely at the Schrader graphs, you can make an approximate conclusion about the hydrogenation of steel in OH (reducing the temperature by 2 times slows down the process by 1.5 times): approximately 5.93 cm 3 / kg at 18.75 degrees Celsius - but the time of penetration into the metal of such a volume is not indicated. In the book by Sukhotin A.M., Zotikov V.S. "Chemical resistance of materials. Handbook" on page 95 in table 8 shows the effect of hydrogen on the long-term strength of steels. It makes it possible to understand that the hydrogenation of steels with hydrogen at a pressure of 150-460 atmospheres changes the ultimate strength by a maximum of 1.5 times in the interval of 1000-10000 hours. Therefore, it is not necessary to consider the hydrogenation of steels during electrolysis in well as a destructive factor.

(added 06/17/2016) Good way disassembling the battery: do not flatten the case, but dissolve it like a tulip bud. From the positive input, piece by piece, bend down the parts of the cylinder - the positive input is removed, the graphite rod is exposed - and smoothly unscrewed with pliers.

(added 06/22/2016) The simplest batteries for disassembly are Ashanov's. And then in some models there are 8 circles of plastic to fix the graphite rod - it becomes difficult to pull it out, it starts to crumble.

(added 07/05/2016) Surprise: a graphite rod is destroyed much faster than an anode made of metal: in just a few hours. Using stainless steel as an anode is the best solution, if we forget about toxicity. The conclusion from this whole story is simple: electrolysis should be carried out only in the open air. If this role is outdoor balcony- do not open the windows, but pass the wires through the rubber door seal (just press the wires with the door). Taking into account the current during electrolysis up to 8A (Internet opinion) and up to 1.5A (my experience), as well as the maximum voltage of the PC PSU 24V, the wire must be rated for 24V / 11A - this is any wire in insulation with a cross section of 0.5mm 2.

Now about iron oxide on an already machined part. There are parts that are difficult to crawl into to erase black plaque (or an object under restoration, when you can’t rub the surface with an iron brush). When analyzing chemical processes, I came across a method for removing it with citric acid and tried it. Indeed, it also works with FeO - the plaque disappeared / crumbled for 4 hours at room temperature, and the solution turned green. But this method is considered less sparing, because. acid and metal eats up (cannot be overexposed, constant monitoring). Plus, a final rinse with a soda solution is required: either the acid residue will eat up the metal in air, and an undesirable coating will be obtained (an awl on soap). And you need to be careful: if as much as 6CO is released with Fe 2 O 3, then what is released with FeO is difficult to predict (organic acid). It is assumed that FeO + C 6 H 8 O 7 \u003d H 2 O + FeC 6 H 6 O 7 (formation of iron citrate) - but I also release gas (3Fe + 2C 6 H 8 O 7 → Fe 3 (C 6 H 5 O 7) 2 + 3H 2). They also write that citric acid decomposes in light and temperature - I can’t find the correct reaction in any way.

(added 07/06/2016) I tried citric acid on a thick layer of rust on nails - it dissolved in 29 hours. As expected: citric acid is suitable for the purification of metal. For cleaning thick rust: apply a high concentration citric acid, high temperature (up to boiling), frequent stirring - to speed up the process, which is inconvenient.

A solution of soda ash after electrolysis, in practice, is difficult to regenerate. It is not clear: add water or add soda. The addition of table salt as a catalyst killed the solution completely + the graphite anode collapsed in just an hour.

Total: coarse rust is removed by electrolysis, FeO is pickled with citric acid, the part is washed soda solution- and it turns out almost pure iron. Gas in the reaction with citric acid - CO 2 (decarboxylation of citric acid), a darkish coating on iron - iron citrate (cleans off easily-medium, does not perform any protective functions, soluble in warm water).

In theory, these methods of removing oxides are ideal for recovering coins. Unless weaker proportions of reagents are needed for a lower solution concentration and lower currents.

(added 07/09/2016) Conducted experiments with graphite. It is during the electrolysis of soda ash that it collapses extremely quickly. Graphite is carbon, when dissolved at the time of electrolysis, it can react with steel and precipitate iron carbide Fe 3 C. The condition of 2000 degrees is not met, however, electrolysis is not NU.

(added 07/10/2016) In the electrolysis of soda ash using graphite rods You can not increase the voltage above 12V. A lower value may be needed - keep an eye on the graphite breakdown time at your voltage.

(added 07/17/2016) Discovered the local rust removal method.

(added 07/25/2016) Instead of citric acid, you can use oxalic acid.

(added 07/29/2016) Steel grades A2, A4 and others are written English letters: imported and from the word "austenitic".

(added 10/11/2016) It turns out that there is another type of rust: iron metahydroxide FeO(OH). It is formed when iron is buried in the ground; in the Caucasus, this method of rusting strip iron was used to saturate it with carbon. After 10-15 years, the resulting high-carbon steel became sabers.

The find must be protected from impacts and other loads. After removal from the earth, irreversible changes begin in the find. The method should be started within a few days. If this is not possible, then it can be stored by creating the same conditions as in the ground. It is harmful to store in water, kerosene, dry room.

Immediately before applying the method, it is necessary to remove the earth with the help of alkali ("Mole"). To do this, fill the find for 1 hour with an alkali solution, then rinse with water. You don't need to use any brushes. Hereinafter, we protect our hands and eyes. Alkali is not compatible with Aluminium, Magnesium, Zinc.

Furnace and reactor

The reactor must be welded on all sides with a strong, reliable hermetic seam. The plug must be secured with bolts that can be easily replaced. The plug must not be sealed. Optimal Thickness reactor walls 2 mm for ordinary steel or 1 mm for stainless steel. The shape of the reactor should be such that the finds are inside at the same, if possible, minimum distance from the walls on all sides.

Charcoal is used as carbon, crushed to granules, the size of peas. Such coal gives a lot of dust, which is very harmful. Therefore, for mass work, it is better to use activated coconut charcoal for water filtration.

Container for boiling

Boiling tank is a welded rectangular trough made of ordinary sheet steel with a lid and a tap for draining.

Algorithm

1. First warm-up

2. After warming up, all rust is restored to pure iron powder. The color of the find should change from red to light gray. If the color is light gray, then you can proceed to step 3. If the color is black, then this means that the rust has not been reduced to iron, but to iron oxide II. In this case, you need to take measures to increase the temperature and / or holding time and repeat step 1

3. Finds are placed in a vat and filled with alkali (Mole). Cooking time 30 minutes - 1 hour of active boiling. After cooling, drain the alkali, rinse the finds with running water without removing them from the container.

4. Wear rubber gloves. Prepare sandpaper, files, needle files, hacksaw blade, knife. cook running water. Under the action of alkali, powdered iron turns into a gel. Using any of the listed tools, we level the gel on the surface of the find, like butter on bread. We carefully cut off the growths, open the holes, clean the bushings. Rinse periodically with running water. This item saves time and makes plumbing work easier later, but can only be done before the gel has hardened. Usually an hour +/- after cooking the gel hardens and in this case you should immediately go to step 5. If the find has complex shape and / or requires disassembly, go straight to step 5.

5. Place the finds in a vat and pour in the vinegar. Concentration: 3 bottles of 0.2 liters of vinegar essence per 5 liters of water. Acid flows into water and not vice versa. Soak in vinegar for at least 1 hour. The color of the finds should change from gray to black with a purple tint.

6. Drain the vinegar, rinse the finds with water and pour alkali again. Soak for less than 1 hour, rinse with water, lay out the finds and dry. It is not necessary to rinse with water too thoroughly, because the alkali residue on the finds will only protect them until the next heating in the oven. This item is needed only so that the finds do not rust again.

7. Second warm-up

8. Locksmith work. After the second heating, the high-density iron powder areas are converted into metallic iron, the low-density iron powder areas are not converted into metallic iron. Locksmith work is reduced to the removal of powdered iron and the alignment of the restored metallic iron. Often, solderings form at the site of the growths, which also need to be cut down. Most often, a large solder is formed near the sink, in addition, the entire surface of the find can be covered with many small solders that need to be removed. In general, at this stage, the subject needs to be given a final look. Complex mechanisms need to be disassembled and processed each part separately. You need to work carefully, because the restored fragments at this stage have a low hardness, and thin places, edges and edges can be broken under the pressure of the file. Another warm-up is required to normalize the reduced metal and turn into “ringing”, but the surfaces must be clean, white with a metallic sheen. If at this stage it is not possible to bring the find to the final finishing appearance, then paragraph 7 is repeated, and then the plumbing work continues. As steps 7-8 are repeated, the restored fragments harden, turn into a "ringing" and firmly adhere to the surrounding metal. In the case of using electric welding, it is also necessary to repeat steps 7 - 8 to homogenize the welded metal with the historical one.

9. Final warm-up. After the final warm-up, the find should acquire a bright white dazzling color over the entire surface. For cleaning from dust and obtaining a uniform optical reflection, a stainless steel nozzle with a bold pressure is used or polished if necessary. If the find has a dark or uneven color over the entire surface, then step 9 must be repeated, taking measures to eliminate the lack of temperature and / or time.

10. Conservation. For preservation, I use a hot solution of paraffin in turpentine. I personally do not like this preservative, because under it the finds acquire a lead color. Its big plus is that it allows you to quickly pass quarantine.

11. Quarantine. The find is placed in a dry room like a city apartment. If salts remain in the depths, then after 2 weeks a local spot of saturated reddish color will appear on the surface of the find around a small crack or shell. Most often this is observed in massive objects and is a consequence of a lack of temperature and / or time in step 9. If at the stage between points 9 and 10 water, splashes, drops of sweat got on the find, or it was affected by high humidity, then after 2 weeks a thin, not bright coating of red flowers will appear on the surface. In either of these two cases, points 9 and 10 must be repeated.

12. Hardening, bluing, darkening, debugging mechanisms, installation on wood

13. Repeat steps 9 and 10 if necessary.

offline granddad

granddad

• Moscow city

Production of a furnace for the restoration of iron in a carbon environment

Small artifacts can be restored in an ordinary village brick oven which includes a small reactor, but for the restoration of blades, gun barrels, the home furnace is too short. Sergei made a special furnace for a large reactor and showed the technology of its manufacture.

The design of the furnace is exactly how I imagine it based on experience, without pretensions to the only possible option.

The furnace should provide long-term heating of the object up to 1000C. The optimum temperature range is 900-1000C. In the case of processing objects decorated with non-ferrous metals or having parts made of non-ferrous metals, the temperature must be below the melting point of the non-ferrous metal.

A pipe was taken to make the furnace large diameter. You can buy used. The length of the pipe is such that any gun or saber placed in the reactor enters into it with reserves.

Three air ducts are installed to improve draft and uniform heating of the long furnace.

I installed dampers on the nozzles that make it possible to reduce traction and thereby increase the effective operating time of the stove without opening the damper for laying firewood.

The main thing in any furnace is good traction, which is provided by a high straight pipe. The higher the pipe, the better the traction. The pipe diameter must not be less than 180 mm.

Grids and blower, an integral part of any stove.

Hangers for fastening the reactor.

Furnace insulation. Our furnace is not for heating, but for creating an optimally high temperature inside the furnace of 900-1000 degrees and heating the reactor placed in it. To achieve high temperatures, we “insulate” the oven with mineral wool.

We also isolate the oven door and weld it.

The furnace is ready, you can start restoration.

The found gun of the 1812 model of the French soldier rather resembled a piece of pipe, and shapeless parts to it, which in the air will very quickly begin to crumble. We carefully removed everything that rings under the metal detector coil from the ground, and without cleaning it, as it is, put it into the reactor together with the ground. We hang it on hangers. We load the stove with wood and set it on fire.

Shotgun after restoration.

Shotgun lock before restoration and after restoration.

How does the metal behave some time later after such treatment? Will it corrode intensely?

Rust spots may appear if you put wet artifacts in the reactor. Spots appear after two weeks. Also, if the item has been exposed to rain. Every drop of rain will leave a red coating. In any case, you need to use paraffin for conservation, since in some apartments the humidity is not less than in a barn. Local corrosion also appears due to insufficient heating temperature, especially if the object is massive and this applies to finds preserved with paraffin. I use this fact as a quality test. If you place a finished object preserved with paraffin in a damp shed, then corrosion centers will not appear at all if the transformations have taken place safely in the deep layers. In general, the metal behaves a little more resistant than non-galvanized nails. Surprisingly, there are items that do not rust at all even in a wet barn for six months.

For conservation, you can use bluing, which was described earlier on this site.

P.S. This method was tested on many artifacts and showed excellent results. Many things, even such miniature ones as needles and carnations from the time of Ivan the Terrible, have perfectly recovered and restored their properties. Needles can be sewn even now. I want to thank Sergey for the story and practical advice about the much-needed method of restoration.

offline granddad

granddad

• Moscow city

For restoration, you will need an iron box with a bolted lid, crushed charcoal (on which we fry kebabs) and a rustic oven.

So, in order. The find, first of all, must be preserved in the form in which it was discovered with pieces of earth, if you dug it up, and rust. It is not necessary to try to "forcibly" clean it from the earth or from exfoliating rust mechanically or in any other way.

If you fished an item out of a pond, wrap it in bandages like a mummy. This will prevent the metal from flaking as it dries.

In an iron box, let's call it a "reactor", crushed charcoal is poured so that our iron objects do not come into contact with the walls of the reactor. The reactor is completely filled with coal, closed with a lid and placed in a melted oven on a pillow of orange coals and overlaid with firewood on all sides. pay attention to temperature regime, the "reactor" must be red-hot.

After about 2 hours, it is necessary to remove the “reactor” from the oven and allow it to cool completely. Please note that only completely dried items are loaded into the reactor.

No metal is subject to such strong destruction in the soil as iron and its alloys. The density of rust is about two times less than the density of metal, so the shape of the object is distorted. Sometimes it is impossible to determine not only the shape of objects, but also the number of objects. When rust is formed in the soil, particles of the earth, organic substances, which gradually become overgrown with corrosion products, get inside it. All this distorts the shape of the object and increases its volume. After being removed from the soil, iron objects must be immediately restored.

Land clearing. The object is soaked in water or cleaned in a 10% solution of sulfamic acid, which dissolves the silicate constituents of the soil, but does not interact with iron and its oxides. When cleaned in acid, the item may disintegrate into fragments that were previously cemented by the earth. Areas of the object that are not cleared of the ground after the first treatment are sprinkled with dry crystalline acid (without removing the object from the resulting solution). Soil deposits are removed with a hot solution of sodium hexametaphosphate. After cleaning, rinsing in tap water and then in distilled water is sufficient.

Having cleared the object from the earth, it is determined in what state the metal is - in active or stable.

Stabilization. Iron objects after being removed from the soil during storage are quickly destroyed. Almost all the changes that could occur under these conditions occurred in the soil with metal, and a certain thermodynamic equilibrium between the metal and the environment was established. After being removed from the soil, the object begins to be affected by a higher oxygen content in the air, different humidity, and temperature changes. One of the main reasons for the unstable state of iron archaeological objects during storage is the presence of active chloride salts in the corrosion products. Chlorides enter from the soil, and their concentration in the object may be higher than in the surrounding soil due to specific reactions that occur during electrochemical corrosion. A sign of chloride salts is the formation of dark rusty moisture droplets at a humidity above 55% in place of an increased chloride content due to its high hygroscopicity. When dried, a kind of fragile shell with a shiny surface is formed. The presence of such dried rust does not mean that the chloride stimulant has ceased to be active. The reaction started elsewhere, and the destruction of the object continues.

To detect chlorides in corrosion products, the object is placed in a humid chamber for 12 hours. If chlorides are found, the metal must be stabilized. Without stabilization, an object may actually cease to exist (crumble into many shapeless pieces) within one or several years.

Then the presence of a metal core or its residues is determined, since an active destruction process occurs in objects with preserved metal, which reacts with chlorine ion. To determine the metal in an object, use:

1) magnet;

2) radiographic method (interpretation of radiograms is not always unambiguous);

3) measurement of the density of an archaeological object. If the specific gravity of the object is less than 2.9 g/cm3, then the object is fully mineralized; if the specific gravity exceeds 3.1 g/cm3, then the object contains metal.

Stabilization by complete cleaning from corrosion products. The complete removal of all corrosion products also leads to the removal of active chlorides. If the metal core is sufficiently massive and reproduces the shape of the object, then a complete cleaning of the iron object by electrolytic, electrochemical and chemical methods is possible.

Stabilization while preserving corrosion products. The shape of an object with a small iron core should be preserved even at the expense of oxides, bringing them to a stable state. Therefore, most important operation, on the thoroughness of which the future safety of the object depends, is its desalination, the removal of chlorine-containing soluble compounds or their transfer to an inactive state.

We give almost all the methods used to stabilize the archaeological, oxidized iron, since only by experience can you choose the best option for the most complete desalination for the restored group of objects.

Rust converter treatment. To stabilize the rust of an archaeological iron object, a tannin solution is used (as in the restoration of museum iron), the pH of which is lowered to 2 with phosphoric acid (approximately 100 ml of 80% acid is added to 1 liter of solution). This pH ensures the completeness of the interaction of various iron oxides with tannic acid. A wet object is wetted with acid solutions six times, after each wetting the object must dry in the air. Then, with a solution of tannin without acid, the surface is treated four times with intermediate drying, rubbing the solution with a brush.

Removal of chlorides by washing in water. The most common, but not the most effective way removal of chlorides, is leaching in distilled water with periodic heating (organ method). The water is changed every week. Washing in water is lengthy, for example, massive objects with a thick layer of corrosion products can be washed for several months. To control the process, it is important to periodically determine the content of chlorides with a sample of silver nitrate.

Cathodic reduction treatment in water. More effective than washing in water is desalination by reductive electrolysis using current. Under the influence of an electric field, a negatively charged chlorine ion moves to a positively charged electrode. Thus, if the negative pole of the power source is connected to the object, and the positive pole is connected to the auxiliary electrode, then the desalination process will begin. First, ordinary water is poured into the bath. tap water with the required conductivity. The objects are placed in an iron mesh, which is wrapped with filter paper, which is a semi-permeable partition for chlorides. A lead plate is used as the anode. The anode area should be as large as possible, this allows you to speed up the process. The current density is 0.1 A/dm2. When the unit is connected to the network, a significant amount of a cloudy substance is first formed, consisting of sulfates and carbonic salts in the water. Gradually, the formation of these salts stops. As it evaporates, distilled water is added to the bath.

Alkaline wash. The use of a 2% sodium hydroxide solution for washing reduces the desalination time, which is caused by a higher mobility of the OH- ion, which allows it to penetrate into the corrosion products. The solution is heated to 80-90°C at the beginning of the washing; intermittent agitation speeds up flushing”; The solution is replaced with fresh every week.

Alkaline sulfite treatment. The treatment is carried out in a solution containing 65 g/l of sodium sulfite with 25 g/l of sodium hydroxide at a temperature of 60°C.

The reductive treatment causes the dense ferric compounds to be reduced to less dense ferrous compounds, i. e. to an increase in the porosity of corrosion products and, accordingly, an increase in the rate of removal of chlorides.

Treatment ends with boiling in several changes of distilled water.

Heating to red heat. The method of heating to red heat is used for objects in which almost all of the metal has turned into corrosion products. This method was first used in the restoration of metals by Rosenberg in 1898. However, it is still used by some restorers. The sequence of operations is as follows: the object is dipped in alcohol and dried in a vacuum cabinet. Then they are wrapped in asbestos and wrapped around with a thin wire of pure iron, the asbestos is moistened with alcohol. An object is heated in a conventional oven at a rate of 800 ° per hour. During heating, corrosion products are dehydrated, turning into iron oxides, chlorides decompose. Then the object from the oven is transferred to a vessel with a saturated aqueous solution of potassium carbonate and kept in it for 24 hours at 100°C. Then washed in distilled water with periodic heating. The water changes every day. The duration of such washing is selected empirically.

After restorative processing and washing, it is recommended to treat the object with tannin according to the method already described.

Mechanical processing of an archaeological iron object. The next step in the restoration of oxidized archaeological iron objects or objects in which the metal core is small in relation to the mass is mechanical processing - the removal of irregularities, swellings, etc. to give integrity to the form. In some cases, the brittleness of oxidized iron is so great that it is impossible to process it mechanically without preliminary strengthening. To strengthen, it is necessary to treat with tannin, as described above, soak with wax or resins. With proper tannin treatment, the object acquires strength sufficient for mechanical processing. It is more reliable to carry out the impregnation in a vacuum when heated.

For mechanical processing, files, sandpaper, burs, etc. are used. If iron oxides are present on the object in the form of magnetite, which is very hard, then diamond or corundum tools are used for processing. During machining, it is unacceptable to cut out an object from a piece of oxides, the shape of which can only be assumed. It is better to stabilize the archaeological find.

If a metal core is preserved in an archaeological iron object, the corrosion products must be completely removed, even if the surface texture turns out to be damaged by corrosion. It is possible to clean such an object after a preliminary study by any chemical method or restoration with or without current.

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