Electrolysis rust cleaning
Hello all. Many people have heard about the electrolytic method of cleaning rusted parts. But, probably there are those who have little idea about this extremely useful action, which can easily replace a brush and sandblasting. Here we have a very rusty but smooth disk. It was of course possible to work on it a bolter with a brush an hour and a half, but I went the way for the lazier – the method of electrolysis.
This requires: 1.Container for the solution – I bought a large basin of rubber (in principle any dielectric will do) 2.The substance, aqueous solution which will be the electrolyte – best of all baking soda, food or calcined, it does not cause chemical burns (like alkali) and washed easily, does not contribute to further corrosion (such as table salt, chloride ions, which then difficult to wash. 3. Water. 3. Water: Normal tap water.
4. a constant current source. Preferably between 12 and 24 volts and with current control and display. A battery charger or computer power supply will work.
I use an old 20 amp battery charger with current and voltage indication and step regulation. 5. Positive electrode-anode. The best material for it is stainless steel. If you do not have stainless steel, you can take black as a last resort. But an electrode of ordinary steel will dissolve quickly.
We are going to put water into the electrode. We make a liquor. How much soda per liter of water is difficult to say. It depends on the shape of the part, the distance between the electrodes, the voltage. I am guided by the current. For the basin I took about 600 grams of soda ash. Fix the “-” of the source to the part (it will be a cathode). There are a lot of ways. You can use wire clamps (with wire clamps you can peel the paint), you can use a bolt like I did. The main thing is to have good contact. Dip the part in the mortar.
Fix “+” from the source to the anode. Anode, as I’ve already written, should be made of stainless steel. Normal steel will dissolve, but if you don’t have at hand an old unnecessary spoon / fork or a trough from an old washing machine, at one time will do and black. I have noticed, however, that if you use regular steel for the anode, it settles on the workpiece dark plaque, which then need to be washed off.
Ideally the anode should be shaped to cover the whole area of the workpiece, otherwise the process will not go evenly from different sides and the workpiece will have to be turned over. In practice it is difficult to make such an electrode, especially if you are cleaning a large-sized item, so you still have to twist the part. Personally, in this case I made the electrodes out of black iron, since I couldn’t find any stainless steel at the moment. Here is the shape of the electrode for cleaning the front side of the disk: For the reverse side: Dip the anode into the solution. WARNING: The anode and the workpiece must not touch, there must be a gap of solution or dielectric.
Turn on our current source. All begins to boil in the basin – the process begins. If there are gauges, then look at them. The rate of cleaning depends on the amount of current that goes through the electrodes. And it, in turn, depends on the power of the source.
You can adjust the current in 3 ways: 1. The source itself (if of course there is a possibility to regulate it) 2. Concentration of soda – more soda in the solution more current. 3. 3. The distance between the anode and the item you are cleaning. The closer they are, the higher the current.
What you set the maximum current depends on your source. You can have at least 100A, but you better not fanaticism, it’s better to wait an hour or two than to burn your device, especially if it’s not protected by overload and overheating. Personally, I put 10-15A.
You should also take into account that at high current the solution heats up (you get a salt heater). This is what the solution looks like after an hour of cleaning, borscht brews great)))) After a few hours of cleaning we take the part out and clean the departed rust with a metal brush under running water, and look at the result. If the rust is still present we leave it for a couple of hours. Here is the result: Front side Inner side No rust at all. Here is an example of cleaning the brake caliper of the VAZ 2108
WARNING: The gases that are produced during electrolysis are hydrogen and oxygen. Their mixture is called rattlesnake gas, though not poisonous, but very explosive! Therefore, work in a very well-ventilated room, or in the fresh air!
Removal of rust by electrochemical method: Features
Rust is a red coating on iron and its alloys consisting of iron oxides. It is formed by destroying the surface of the metal and needs to be removed, otherwise after a while the entire metal object will rust through and break. There are different ways to remove rust, one of which is electrochemical.
How to remove rust with electrochemicals
The use of special chemicals can remove corrosion without much harm
You can remove rust in different ways:
- The simplest – mechanical, with the help of a special attachment drill, sandpaper, grinder or file. This method is only suitable for flat and smooth surfaces, as threads or shaped castings are easy to scratch when removing the top layer.
- The chemical method using “folk” recipes: citric or hydrochloric acid, apple cider vinegar, Coca-Cola (which contains orthophosphoric acid). But it is more effective and safe to use special pastes. Under the influence of acid, iron oxides dissolve and turn into salts. However, acids have a negative effect on the iron itself, destroying it, and therefore it is important to observe the specified time and thoroughly wash and dry the parts.
Important! Electrolysis is used in industry and at home.
Advantages and disadvantages
Electrochemical method is effective and simple, it can be used in the home.
The advantages of the electrolysis method include:
- Safety for the part: the surface of the object will not be scratched by mechanical brushes and will not be damaged by exposure to chemicals;
- Efficiency: this method removes even multi-year and multi-layered rust;
- Cheap: despite the apparent complexity, the necessary things for the procedure are inexpensive (for example, you can use any plastic container, collect water from the tap);
- Lack of effort: it is necessary to connect the wires, turn on the current and check the part regularly. It is not necessary to exert effort and scrape off corrosion by hand;
- It is possible to clean objects of any company, without restrictions.
An important disadvantage is the process itself: since you have to work with electricity and active chemicals, you need to follow safety procedures and be extremely careful in the process.
What you need to remove rust
Even a cut off plastic bottle can be used for electrolysis
How to remove rust with electrolyte? You will need to prepare several items for this:
- A plastic or rubber container;
- A power source with a voltage of 12-24 V, for example, a computer power supply or a car battery will do;
- Wires with stripped ends or terminals;
- A substance that will act as the electrolyte. Any powder that contains sodium will do: baking soda or soda ash, salt, caustic soda;
- Positive electrode-anode: a piece of stainless steel or galvanized steel will do. It is recommended to use exactly soda, as it is the most effective and at the same time safe;
Note: Any container made of dielectric will do.
Order of cleaning
Soda is required for cleaning.
The cleaning procedure is simple:
- You need to pour water into a container and dissolve soda in it in the proportion of 1 tablespoon of soda per 1 liter of water;
- Scrape off a small section of the rusty part with sandpaper and connect the negative wire or terminal to it;
- Dip the part into the water so that the part with the connected wire does not go under the water;
- Connect the positive wire or terminal to the stainless steel;
- Turn on the current.
Once the current is applied, a reaction will begin. This can be determined by the active release of air bubbles into the water. If there are few bubbles, then the reaction is weak and it will take a long time to remove the corrosion. You can intensify the process by adding more baking soda.
Note: To speed up the procedure, you can remove paint and top loose rust layer from the rusted part beforehand.
The time of the procedure is individual – from a few minutes to 10 hours. At times it is necessary to turn off the power, remove the part from the water and rinse it. When rinsed, flakes of rust will fly off of it. If the part is clean, it should be dried, if not, you can put it back down and continue.
During cleaning, pieces of rust will fly off the metal.
Safety precautions must be observed when using electrolysis:
- Carry out the procedure in a well-ventilated room, preferably outdoors;
- It is important to ensure that the entire apparatus is earthed: utensils should be rubber or plastic, and hands should wear tight rubber gloves;
- Wires should not have accidental contacts so as not to break the connection, it is also important not to mix up the terminals;
- If the rusty object has any value, it is better not to use the electrochemical method for cleaning, it is worth stopping at cleaning with a chemical agent, because there is a great chance not to keep track and spoil.
Also, you must not forget about safety when working with electricity.
Important! Sold ready-made sets for removing rust “Cincor-Auto”, which has everything you need to conduct a reaction on 1 square meter of rusty surface.
Common mistakes and how to avoid them
The best way to avoid mistakes is to clearly follow the instructions and do not forget about protection.
The scheme will help to better understand the order of the cleaning.
Common mistakes include:
- Improperly securing the terminals. It is extremely important to connect the wires correctly (positive to the stainless steel, negative to the part), it is better to double-check this before turning on the current;
- Using salt instead of baking soda. Nothing terrible will happen, but many have noted that with salt the reaction is less active and worse cleansing;
- The use of too weak or strong current. In the first case, the reaction will be weak and of little use, in the second – the current source can fail, “burn”;
- Too long exposure. In the worst case, the part will turn black and will not wash off. Since the exposure time cannot be determined even approximately, it is worth checking the process more often. Even seemingly identical parts can behave differently.
Electrochemical rust removal is the safest and most effective method. The essence of electrochemistry is to run a weak current through a soda solution, which causes an electrolytic reaction. Carry out cleaning in this way can be done at home if you observe the safety precautions.