Disposal of old household appliances is often seen not only as a way to free up space, but also as an opportunity to make a small profit from disposing of non-ferrous metals. The design of a modern refrigeration unit contains a significant amount of valuable materials, among which the leader copper. The highest concentration of this metal is concentrated in the compressor, which is essentially a complex electric motor. However, the extraction process requires not only physical effort, but also compliance with strict safety rules.
Before proceeding with disassembly, it is important to understand that refrigeration compressor is a sealed unit that is under pressure and contains residual refrigerant. You can’t just cut it like that, as this can lead to the release of harmful substances or even an explosion of oil vapor upon contact with a spark. The exact copper yield depends on the model and year of manufacture of the unit, amounting to on average from 0.6 to 1.2 kg of pure metal. A competent approach to dismantling will maximize profits and minimize health risks.
In this article we will look in detail at the preparation process, the necessary tools and the stages of cutting the compressor. You will learn how to distinguish copper from other alloys and why some engine parts should not be taken to a collection point. Issues of environmental safety will also be raised, because proper handling of equipment waste is the responsibility of each owner.
Assessment of potential: how much copper is in the compressor
The first stage is always a visual assessment and weighing. A standard household compressor weighs from 8 to 12 kilograms. Hidden inside this metal casing is a stator winding made of copper wire. The amount of metal directly depends on the engine power and its efficiency. Modern models often use thinner wire and less iron, but old Soviet units can contain up to 1.5 kg of copper, although their body is heavier.
It is worth considering that scrap acceptors value copper differently: electrical copper (pure) is more expensive than windings in insulation or mixed with varnish. Therefore, the master’s task is to clean the wire as much as possible from dirt and foreign materials. Weight of copper winding is approximately 10-15% of the total mass of the compressor. The rest is steel, cast iron and oil.
For an accurate understanding of what you are dealing with, check out the approximate metal output data depending on the type of compressor:
| Compressor type | Total weight (kg) | Stator weight (kg) | Approximate copper output (kg) |
|---|---|---|---|
| Single-phase (household) | 9-11 | 1.2 - 1.5 | 0.7 - 0.9 |
| Double-motor (old) | 14-16 | 2.0 - 2.5 | 1.1 - 1.4 |
| Inverter (new) | 7-9 | 0.8 - 1.1 | 0.5 - 0.7 |
| Industrial | 25+ | 5.0+ | 2.5 - 3.5 |
The actual output depends on the manufacturer and series. For example, models Atlant or Indesit often use aluminum in some heat exchanger elements, but the motor windings are almost always copper. Aluminum windings are extremely rare and only in the cheapest modern models, which immediately reduces their value for the deliverer.
Required tools and safety measures
Disassembling a sealed housing requires a specific set of tools. A regular set of wrenches will not be enough here. You will need an angle grinder (grinder) with metal discs, powerful wire cutters or metal scissors, a hammer, a chisel and pliers. It would also be useful to have a vice for fixing heavy engine parts during operation.
⚠️ Attention! Before starting work, make sure that the compressor is completely disconnected from the power supply and that the oil has been removed from it. When sawing the housing, residual oil may ignite from a spark. Work in a well-ventilated area, away from flammable objects.
Personal safety is priority number one. Metal shavings and dust generated during cutting are hazardous to the eyes and respiratory tract. Be sure to use safety glasses, thick gloves and a respirator. Clothing must cover arms and legs to prevent hot scale from getting on the skin.
☑️ Safety checklist
Special attention should be paid to choosing a disc for the grinder. To cut a thick compressor housing, it is better to use disks with a thickness of at least 1.6 mm, since thin ones can burst under lateral load. Protective casing It must be installed and secured on the tool according to the instructions of the power tool manufacturer.
Preparing the compressor for opening
The first step in the extraction process is to remove external elements. It is necessary to remove the starting and protective relay from the compressor, as well as the capacitor, if it is attached to the housing. These elements contain little valuable metal, but can interfere with further cutting. Carefully disconnect the wires, biting them closer to the terminals so as not to damage the internal insulation of the winding.
Next, you should remove the copper tubes. They are soldered to the case and lead into the system. Cut them with a grinder or saw them off with a hacksaw at the very base. High and low pressure tubes can be sold separately as copper scrap; they do not need to be cleaned of solder, since its percentage is minimal. This is a ready-made non-ferrous metal.
The next critical stage is removing the oil. The compressor crankcase contains about 200-300 grams of compressor oil. If you start sawing a full unit, the oil will spread, creating a slippery and fire-hazardous surface. Turn the compressor upside down over a container (for example, a cut canister) and wait for the oil to drain. You can slightly shake the unit to speed up the process.
Technology for opening the housing and removing the stator
The most labor-intensive stage is opening the sealed “pot”. The compressor housing consists of two bowls welded along the equator. Your job is to make a cut along this weld. Clamp the compressor in a vice or securely fix it with your foot (wearing thick shoes). Make the cut carefully, trying not to touch the internal parts, although it is unlikely that you will be able to completely avoid contact with the winding when sawing.
After the circular cut is made, the top cover (dome) can be removed. Sometimes it sits tightly due to corrosion or residual pressure. Light blows with a hammer around the perimeter will help separate the parts. Inside you will see an electric motor and a piston group. The engine is mounted on springs or rigid suspensions inside the housing.
⚠️ Attention! There may be an asbestos gasket or thermal insulation materials inside the housing. Try not to create dust with them and immediately pack the removed cover in a tight bag for disposal.
Now you need to remove it yourself electric motor. It is supported by three springs or brackets. Cut the wires going to the winding if this has not been done previously. Pull the “stuffing” out. The stator (fixed part with winding) and rotor (moving part) can be connected. Your target is the stator. The rotor is a set of steel plates and there is practically no copper there; it can be put aside like ferrous metal.
What to do if the body cannot be sawn?
In some models, the body is made of especially strong steel or has a non-standard seam shape. If sawing along the equator is inconvenient, you can make two parallel cuts on the side surface and knock out the wall with a chisel. The main thing is to get to the stator without damaging the winding excessively, although the integrity of the turns is not critical for scrap delivery.
Cleaning copper from insulation and varnish
The resulting stator is a package of metal plates, in the grooves of which there is a copper wire coated with varnish. It is not profitable to hand over the stator in this form: it will be assessed as “copper in a mixture” or “winding”, which costs 30-40% less than pure copper. Therefore, the wire must be stripped of its insulation.
There are several cleaning methods. The mechanical method involves cutting down one of the stator bases (where the ends of the wires are visible) with an ax or grinder. The bundles of wires are then pulled out of the grooves. After this, the wire is cleaned of varnish. The use of a chemical method (burning) is not recommended: when burning varnish, toxic substances are released, and thin copper can oxidize and lose weight.
The best option is to use a special machine for cleaning the wire or manual stripping with a knife/sandpaper, if the volumes are small. Varnish it burns or is cleaned off, leaving a shiny metal Pure copper has a characteristic reddish-golden hue. If the metal is dark or green, these are oxides that reduce the price.
The remaining iron core (set of plates) also has value, but as black scrap or electrical steel. It can be handed over separately, having previously dismantled all remaining copper. Separation of metal flows is the key to successful scrap delivery.
Sorting and delivery of scrap: expert advice
Once the copper has been extracted and cleaned, the sorting stage begins. Metal collection points strictly classify scrap. Copper M1 - this is clean, unoxidized wire without insulation. M2 - may have small oxides or traces of soldering. Mix - wire in insulation, with varnish, with solder residues. It is clear that the price for M1 will be maximum.
Do not try to mix copper with brass (yellow metal) or bronze. An experienced receiver will immediately notice the substitution and lower the price for the entire shipment. Brass bushings that may be found in the compressor design must be separated. Also, make sure that no pieces of steel get into the copper - they can be easily checked with a magnet: copper does not magnetize, steel does.
- 🔥 Dry copper is valued higher, so store the workpiece in a dry place before handing it over.
- 🧲 Check with a magnet required: if a piece of “wire” sticks to magnet, it is a bimetal or steel with copper plating, the price for it is minimal.
- ⚖️ Weigh it copper on home scales in advance in order to roughly understand the weight and not be deceived at the receiving point.
When When handing over a large number of compressors, it makes sense to agree with the receiver in advance. Larger shipments are often accepted at a higher rate. Also check if they accept the remains of casings as black scrap, so as not to litter the site.
Frequently asked questions (FAQ)
How much can you earn on one compressor?
Income depends on current prices for scrap and the weight of the extracted copper. On average, about 0.8 kg of copper comes out of one compressor. If the price of copper is about 600-700 rubles per kg, then “dirty” from one motor you can get 400-500 rubles, minus the cost of electricity and tools. Iron costs pennies, so the main income is copper.
Is it possible to mine copper without a grinder?
Theoretically, yes, but it is extremely labor-intensive. You can use a powerful chisel and sledgehammer to break through the body, or saw with a hacksaw, which will take a very long time. However, an angle grinder is the fastest and most effective tool for this task. Without power tools, the process will become unprofitable.
Is compressor oil dangerous?
Yes, used compressor oil contains wear products and chemical impurities. It is toxic and must not be discharged into sewers or soil. Collect the oil in a separate container and take it to a special collection point for hazardous waste or used oils.
Are there other non-ferrous metals in the compressor?
The main non-ferrous metal is copper. Brass (bushings, valves) and aluminum (in some heat exchangers, but not in the motor itself) may be found in small quantities. There are no precious metals (gold, silver) in household refrigerator compressors, despite widespread myths.
What to do with freon?
In old refrigerators that have not been working for a long time, freon usually already evaporates through micro-holes. If the unit was working, when cutting the tubes, the remaining gas will come out. On an industrial scale, freon needs to be pumped out with a pump, but for one household compressor in a garage, this is difficult to do. The main thing is to ensure powerful ventilation of the room during work.