Process Disposing of old household appliances often becomes a serious problem for owners, especially when it comes to large units such as refrigerators. The most valuable element in the design, which attracts the attention of metal collection points, is compressorcontaining a significant amount of copper and steel. However, you can’t just throw it away, and it’s not possible to hand it in intact everywhere, so the issue of cutting the housing becomes relevant for many craftsmen.
Cutting a sealed motor casing is an operation that requires not only physical effort, but also strict adherence to safety precautions, since residual pressure or refrigerant vapor may remain inside. Incorrect actions can lead to injury or damage to the tool, so the procedure must be approached with full responsibility and an understanding of the structure of the unit.
In this article we will analyze in detail what tools are required to open the case, how to prepare the workplace and what stages the safe cutting process includes hermetic compressor. You will learn how to separate the copper winding from the steel casing and how to properly prepare the scrap for maximum profit.
Compressor design and value of components
Before you begin to physically impact the unit, you must clearly understand what exactly is inside the massive black "barrel". Hermetic compressor is a sealed steel casing, inside which an electric motor and a pump group are located. It is this tightness that creates the main difficulties during disposal, since it requires violating the integrity of the housing.
The main value for collection points is copper winding the stator and heat exchanger tubes, which make up a significant part of the weight of non-ferrous metal. The steel body is also recycled, but the cost of ferrous metals is significantly lower, so the main goal is to extract copper without damaging it by fire or contamination.
There are also oil and refrigerant residues inside, which can be dangerous. Modern freons can be non-flammable, but older models often contained flammable or toxic substances, therefore room ventilation is a prerequisite for operation.
⚠️ Attention: Compressor oil, which is a petroleum product, always remains inside the compressor. Drain it only into a special container for subsequent disposal, pour it into the soil or sewer.
Understanding the internal structure helps to choose the right tool. If you chop at random, there is a high risk of damaging the copper, which will reduce its grade and cost, or jamming the tool in the viscous structure of the metal.
Necessary tools and workplace preparation
For effective and safe cutting of the motor, you will need a set of specialized tools. Using household metal scissors will not help here, since the thickness of the casing walls and the strength of the internal components are designed for high loads and vibration.
The best option for work is angle grinder (grinder) with metal discs with a thickness of at least 1.6 mm. Thin discs quickly wear down against a massive body and can burst from misalignment, which is deadly.
In addition to the main tool, you will need:
- 🛡️ Safety glasses or a chameleon mask to protect your eyes from sparks and metal shavings.
- 🧤 Thick work gloves with protection from cuts and vibration.
- 🔧 Set of wrenches and pliers for dismantling external elements.
- 🪣 Container for draining technical oil.
- 🧱 Stops or vices for fixing the compressor during cutting.
The work place should be well lit and ventilated. A garage with a concrete floor or an open area is ideal. Do not work in residential areas or near flammable materials, as sparks from grinders scatter several meters.
Dismantling and preparing the compressor for cutting
The first stage of work is separating the compressor from the refrigeration cabinet and cleaning it of excess elements. Do not try to cut the unit while it is attached to the frame of the refrigerator, this is inconvenient and dangerous.
First you need to cut or saw off the copper tubes that fit the body. This should be done at a distance of 5-10 cm from the soldering point, so as not to damage the threads or fittings if you plan to use them in the future, although this is not critical for scrap.
Next, you should remove the starting relay and the protective thermostat, which are usually attached to the side. These plastic and electrical components are not valuable for scrap metal, but can interfere with cutting or catch fire from sparks.
It is important to drain the oil before starting active work. To do this, the compressor is turned down with its fittings over the prepared container. The process may take from 15 to 30 minutes, since the oil is viscous and drains slowly.
☑️ Preparing the compressor
Technology for safely cutting the housing
The most crucial moment is direct opening steel casing. There are several cutting strategies, but the safest and most effective is considered to be a circular cut along the equator of the housing.
Install the compressor vertically, fixing it between the bars or in a vice (through a soft gasket so as not to damage the vice, although this is not important for scrap). Turn on the grinder and let it reach full speed before touching the metal.
Make a cut in a circle, trying to keep the tool perpendicular to the surface. Don't put too much pressure on the grinder, let the disc do its job. The cutting depth should be approximately 1/3 of the radius of the body so as not to immediately touch the internal windings.
⚠️ Attention: When sawing the body, sparks with a burning smell may occur. This burns off the factory paint and possible oil residues. Work only in a respirator, as the smoke is toxic.
After making a circular cut along the entire circumference, you need to make several radial cuts from the equator to the apex. This will allow you to remove the “cover” of the compressor and gain access to the insides.
What is inside after opening?
After removing the cover you will see a stator with copper windings, a rotor and a cylinder of the pump group. Often the rotor is pressed onto a shaft that is attached to the pump.
Copper extraction and metal sorting
After opening the housing, you will see the “filling” of the motor. The main task is to separate copper winding the stator from the steel plates. This can be done in two main ways.
The first method is mechanical. Using a chisel and hammer, as well as a grinder, one of the sides of the stator package is cut off. After this, the winding is often removed entirely or in large bundles. This allows you to maintain the length of the wire and its purity.
The second method is thermal (burning), but it is less preferable for high-quality copper, since it burns the varnish and can oxidize the metal, reducing its grade. If you still decide to burn, do it in the open air, observing fire safety.
The steel body and internal plates (charging) are classified as black scrap. They can be folded separately. Copper tubes and windings are non-ferrous scrapwhich are valued much more expensive.
| Component | Metal type | Approximate weight share | Processing method |
|:--- |:--- |:--- | |
| Housing (casing) | Steel | ~60% | Cutting, delivery to ferrous metal |
| Stator winding | Copper | ~10-15% | Removing, cleaning |
| Rotor | Steel + Copper/Aluminium | ~15% | Disassembly or entire |
| Tubes | Copper/Aluminium | ~5% | Cutting, straightening |
Typical errors and safety measures
When cutting engines, beginners often make mistakes that can cost their health or damage the metal. One of the most common is an attempt to cut the compressor without securing it. The rotating disc of the grinder can move the unit to the side, which will lead to impact or breakage of the tool.
The use of blunt discs or discs for other purposes (for example, for wood) is strictly prohibited. The compressor steel is hard and viscous; an unsuitable tool simply will not cope or will shatter into fragments.
It is also a mistake to ignore the residual pressure. Even if the refrigerator has been sitting for years, there may be gas in the cavities. Before the first cut, it is recommended to carefully drill a hole in the upper part of the housing with a metal drill to relieve possible pressure.
⚠️ Attention: Never use gas cutters (oxy-acetylene) to cut the compressor unless you are a professional. Remaining oil and coolant in combination with an open flame can cause an explosion or fire.
Following these simple rules will allow you to safely and efficiently dispose of your old motor, while obtaining clean and expensive scrap.
The influence of the type of refrigerant on recycling
Although for mechanical cutting the type gas inside the system does not play a role; it is important for environmental safety. Old refrigerators could contain freon R12, which destroys the ozone layer, or freon R12, isobutane R600a, when depressurized systems, these gases escape. If you smell a strong, specific odor or see gas escaping under pressure, stop work immediately and ventilate the room. Modern requirements for disposal require pumping out freon before disassembling, but in domestic conditions this is rarely done. Freon R12which destroys the ozone layer, or isobutane R600a, which is explosive.
When the system depressurizes, these gases escape. If you smell a strong, specific odor or see gas escaping under pressure, stop work immediately and ventilate the room. Modern recycling requirements require pumping out freon before disassembling, but this is rarely done in domestic conditions.
It is important to understand that burning freon residues in a fire is unacceptable, since at high temperatures they can form toxic phosgene. Mechanical cutting without fire is safer in this regard.
Is it possible to cut a compressor with a hacksaw?
Theoretically it is possible, but it will take a lot of time and require several canvases. The steel of the case is hard, and manual work is extremely labor-intensive. The grinder does the job in 5-10 minutes.
How much copper can be obtained from one motor?
On average, from a standard refrigerator compressor with a volume of 200-300 liters comes out from 100 to 200 grams of pure copper. Weight depends on the model and year of manufacture of the engine.
Is the gas inside the compressor dangerous when cutting?
The residual pressure is usually small, but may be sufficient to cause oil to splash. Gases like R600a (isobutane) are flammable, so sparks from an angle grinder near an open fitting can ignite the mixture.
Do you need to remove the relay before cutting?
Yes, definitely. The plastic on the relay will catch fire from the sparks and may melt and contaminate the copper and create smoke. In addition, there are ceramic elements inside the relay that are not needed in scrap.