How to solder refrigerator tubes at home: selection of materials and step-by-step instructions

Soldering refrigerator tubes is a task that sooner or later every owner of equipment older than 5-7 years faces. Freon leakage, mechanical damage or corrosion of the circuit require surgical intervention, and it is not always possible to call a specialist. If you decide to deal with the problem yourself, it is important to understand: soldering of refrigeration tubes it differs from ordinary plumbing or electrical work. This requires special materials, precise adherence to temperature conditions and accuracy so as not to damage the sensitive elements of the system.

In this article we will understand how to solder copper refrigerator tubes at homewhich solder and flux to choose for a reliable connection, and also describe in detail the soldering process - from surface preparation to testing tightness. You will learn what mistakes beginners most often make (and how to avoid them), what tools are really necessary, and what you can do without. We will pay special attention safety precautions: working with an open flame and refrigerant requires special care.

Before you begin, assess the extent of the damage. If we are talking about a microcrack or a small puncture, do-it-yourself soldering is quite possible. But if the tube is torn over a large area or the evaporator is damaged, it may be more rational to replace the entire part - especially if your refrigerator is under warranty or belongs to the premium segment (for example, Liebherr, Bosch Serie 8).

1. Why you can’t use regular solder for a refrigerator

Many beginners make a critical mistake: they try to solder refrigerator tubes. same tin-lead solder (POS-61), which is used for electronics or plumbing. This is absolutely wrong! The fact is that the cooling system operates under high pressure (up to 15-20 atm in a high-pressure circuit), and ordinary solder does not provide the necessary strength of the seam. In addition, it can react with oil and freon, which will lead to blockage of the capillary tube or failure. compressor.

For soldering refrigeration tubes they use copper-phosphorus or silver-containing solders with a melting point above 600°C. They form a connection that can withstand vibrations and pressure changes. and aggressive refrigerant environment. For example:

• 🔹 Copper-phosphorus solder (CuP) —optimal for copper, does not require flux when soldering clean surfaces, but is not suitable for aluminum parts.
• 🔹 Silver solder (Ag 2-5%) - universal, provides high weld strength, but is more expensive and requires precise temperature control.
• 🔹 Solder with the addition of silver and phosphorus (BCuP) - a compromise option for beginners, spreads well and holds pressure.

Another nuance: in refrigeration systems they are often used aluminum tubes (especially in modern models Samsung, LG, AtlantFor them, ordinary copper-phosphorus solder is not suitable - you will need a special one). data-i="81">(for example, aluminum solder (For example, Castolin 192 or Aluminum 13) and active flux. Soldering aluminum at home is much more difficult and requires experience, so if you are a beginner, it is better to contact a specialist.

⚠️ Attention: Do not use acidic fluxes (for example, hydrochloric acid or soldering acid) for soldering refrigeration pipes! They cause corrosion and destroy the seam from the inside. Suitable only for copper boron flux or borax-based flux paste.

2. Necessary tools and materials: what to buy for soldering

To properly solder the refrigerator tube, you will need a minimum set of tools. Some of them can be replaced with improvised means, but you should not save on key positions - this will affect the results. reliability of repair.

If you are soldering for the first time, we recommend purchasing set for soldering copper pipes (sold in plumbing or refrigeration equipment stores). It usually includes a torch, solder, flux and a cleaning brush. The cost of such a set is from 1,500 to 3,000 rubles, but it will pay for itself after the first successful repair.

Pay attention to torch power. For tubes with a diameter of 6-12 mm (typical for household refrigerators), a burner with a power of 1-1.5 kW is suitable. A burner that is too powerful can overheat the tube and deform it, and a weak one will not provide the required temperature. solder melting.

3. for soldering: stripping and processing

The quality of soldering depends 70% on proper surface preparation. Even if you use the best solder, a poorly stripped tube will not provide a tight connection. Let's start with what you need completely removed. refrigerant from the system:

1. Disconnect the refrigerator from the network and let it stand for 10-15 minutes (so that the pressure in the system drops).
2. Find service port (usually located on the compressor or capillary tube) and release the gas by gently pressing the valve with a screwdriver. Do this outside or in a well-ventilated area! Freon is non-toxic, but in high concentrations it can cause dizziness.
3. If the tube is severely damaged, cut off the damaged area with a pipe cutter, leaving a margin of 1-2 cm with each side for soldering.

Now let's start cleaning:

1. Treat the soldering area with sandpaper until it shines - this will remove the oxide film and grease marks. For copper, 120-150 grit is enough, for aluminum - 240.
2. Wipe the surface. with a clean cloth soaked in acetone or alcohol to remove dust and grease.
3. Apply a thin layer of flux using a brush or stick. Suitable for copper. boron flux (sold in the form of powder or paste), for aluminum - a specialized flux (for example, F-SW21).

Critical important: if you are soldering an aluminum tube, after stripping, do not touch it with your bare hands! Grease marks from your fingers will lead to poor adhesion of the solder. For aluminum it is also recommended to use argon welding (if possible), since soldering this metal at home often results in leaky seams.

4. Step-by-step instructions: how to properly solder a refrigerator tube

When everything is ready, you can start soldering. Work in a well-ventilated area, securely fasten the tube (for example, in a vice or clamp) so that it does not move during heating. Here is a step-by-step algorithm:

1. Connection assembly. If you cut the tube, insert it into flaring (the extended end of another tube) or use coupling the gap between the tubes should be minimal - no more than 0.1 mm.
2. Heating with a torch. Smoothly heat the joint, moving the flame in a circle. Direct the burner on a more massive part (for example, if you are soldering a tube and coupling, heat the coupling). The optimal temperature is when the flux begins to bubble, but does not burn yet.
3. Applying solder. Touch the solder rod to the joint. melt and flow into the gap under the action of capillary forces. Do not overheat! An ideal seam is formed when the solder is “pulled” into the joint, and does not flow from above.
4. Cooling. Allow the seam to cool naturally (do not cool with water!). with a rag - they can cause corrosion.

Visually, a high-quality seam should be:

• 🔸 Smooth, without pores and cracks.
• 🔸 Cover everything evenly connection.
• 🔸 Have a characteristic shine (a matte seam indicates overheating or lack of flux).

If the solder does not spread or the seam turns out to be porous, it means:

• 🔹 The temperature is insufficient (heat longer).
• 🔹 The surface is poorly cleaned (repeat cleaning and applying flux).
• 🔹 Solder is not suitable for this metal (check compatibility).

What to do if the solder does not melt?

If the solder does not melt even with prolonged heating, check:

- Compliance of solder and torch (for example, copper-phosphorus solder requires a temperature of 700-850°C).

- Gas pressure in the cylinder (may be too low).

- Contamination of the torch nozzle (clean with a thin wire).

- Quality of the flux (expired flux loses activity).

5. Checking the tightness: how to make sure that the soldering was successful

Even if the seam looks perfect, it must be checked for leakage of freon. microcracks are one of the most common causes of repeated breakdowns after self-repair. Here's how to check the connection:

1. Visual inspection. Shine a flashlight on the seam - it should be uniform, without voids. Pay special attention to the edges of the connection.
2. Checking with a soap solution. Apply soap to the seam. foam (you can use dishwashing liquid). If bubbles appear, then there is a leak. This method is suitable for checking without pressure.
3. Nitrogen pressure testing. Connect a nitrogen cylinder to the system (pressure 10-15 atm) and leave for 10-15 minutes. If the pressure does not drop, the seam. sealed. For accuracy, you can use pressure gauge.
4. Vacuuming. Connect the vacuum pump and pump the air out of the system to a pressure of -0.9 atm. If the vacuum is maintained for 15-20 minutes, there are no leaks.

If you find a leak, do not try to “cover up” it with additional solder! Disassemble the connection, clean it and solder again. Most often, leaks occur due to:

• 🔸 Insufficient heating during soldering.
• 🔸 Poor surface cleaning.
• 🔸 Using inappropriate solder or flux.

⚠️ Attention: If after soldering you immediately pump in freon, and the seam turns out to be leaky, the refrigerant will evaporate and you will have to repeat the whole procedure again Always. check the tightness of before filling the system!

6. Filling the refrigerator with freon after soldering

When the seam is checked and sealed, you can start filling the system with refrigerant. To do this you will need:

• 🔹 Freon cylinder (type depends on the refrigerator model, usually R134a or R600a).
• 🔹 Manometric manifold (for pressure control).
• 🔹 Vacuum pump (to remove moisture from the system).
• 🔹 Scales for weighing freon (optional, but recommended).

Step-by-step process:

1. Connect pressure manifold to the service port of the refrigerator (usually located on the compressor or filter drier).
2. Open the manifold valve and connect vacuum pump. Vacuum the system for 15-20 minutes to remove moisture. atm.
3. Close the valve and turn off the pump. Wait 10 minutes - if the pressure gauge needle does not move, the system is sealed.
4. Connect the freon cylinder (upside down, if so R600a) and slowly fill the system, monitoring the pressure using the pressure gauge. For R134a the working pressure in the high-pressure circuit is about 10-12 atm, for R600a - 4-6 atm.
5. After refueling, turn on the refrigerator and check the operation of the compressor. After 10-15 minutes, cold should appear in the freezer.

If after refueling the refrigerator does not cool, possible reasons:

• 🔸 Not enough freon (refill).
• 🔸 Clogged capillary tube (purge required nitrogen).
• 🔸 Compressor malfunction (check the windings with a multimeter).

7. Common mistakes and how to avoid them

Even experienced craftsmen sometimes make mistakes when soldering refrigeration tubes. Here are the most common ones and ways to prevent them:

Another typical problem is clogging of the capillary tube after soldering This happens if scale and flux particles get into the system. or moisture. To avoid clogging:

• 🔹 Always flush the system with nitrogen before filling with freon.
• 🔹 Use filter drier (replace it if the refrigerator is no longer new).
• 🔹 Do not overheat the tube - this leads to the formation of scale.

If after repair the refrigerator works, but does not freeze, check:

• 🔸 Freon pressure (possibly underfilled).
• 🔸 The operation of the thermostat (may be faulty).
• 🔸 The cleanliness of the capillary tube (if clogged, the compressor will hum, but the cold will not flow).

8. When soldering is impractical: cases when it is better to call. masters

Despite the fact that you can do the soldering of refrigerator tubes yourself, there are situations when it is better to trust a professional. Here are signs that do-it-yourself repairs can result in even bigger problems:

• 🔹 The evaporator is damaged. or a capacitor. These parts have a complex shape, and their soldering requires special equipment (for example, induction soldering iron).
• 🔹 The tube is damaged in a hard-to-reach place (for example, inside the case or behind the polyurethane foam insulation). Disassembling the refrigerator without experience can lead to damage to other elements.
• 🔹 The refrigerator is under warranty. Independent repair will void the warranty, even if you do everything correctly.
• 🔹 Aluminum tubes. Soldering aluminum at home often results in leaky seams, and argon welding requires professional equipment.
• 🔹 Malfunction of the compressor or electronics. If the problem is not a freon leak, but a breakdown of the motor or control board, soldering the tubes will not help.

It is also worth considering that some models of refrigerators (for example, Samsung No Frost or Liebherr Premium) are used special alloys of tubes, which require a special approach to soldering. If you are not sure about the material of the tubes, contact a specialist or check the information in the technical data sheet of the device.

The cost of professional repair of soldering tubes in a service center ranges from 2500 to 6000 rubles (depending on the complexity and region). If you assess your costs for materials and risks above this amount, it may be more advisable to trust a specialist.

⚠️ Attention: Refrigerators with a system No Frost often use thin-walled tubes. Their soldering requires special care - if overheated, the walls can burn out!

FAQ: Frequently asked questions about soldering refrigerator tubes

Is it possible to solder refrigerator tubes with a regular soldering iron?

No, a regular soldering iron (even with a power of 100 W) does not provide the required temperature for copper-phosphorus or silver solders. For soldering refrigeration tubes it is necessary gas torch with a flame temperature of at least 800°C. The soldering iron is only suitable for soldering electronics or thin wires, but not for systems operating under pressure.

What kind of freon is needed for my refrigerator?

The type of freon depends on the model and year of manufacture of the refrigerator:

• 🔹 R12 —an obsolete refrigerant, used in Soviet refrigerators (Minsk, ZIL, Orsk). Currently not produced, requires replacement with Minsk, ZIL, Orsk - the most common freon for modern refrigerators ( R134a.
• 🔹 R134a - the most common freon for modern refrigerators (Atlant, Indesit, Bosch).
• 🔹 R600a (isobutane) - used in environmentally friendly models (Liebherr, Samsung). More efficient, but fire hazard.
• 🔹 R290 (propane) - rarely found in household refrigerators, requires special equipment for refilling.

The exact type of freon is indicated on the refrigerator nameplate (usually pasted on the back wall) or in the technical data sheet. Never refill the system by eye! Incompatible freon can cause damage compressor.

How much freon is needed for refilling?

The amount of freon depends on the volume of the refrigeration chamber and the length of the pipes On average:

• 🔹 Single-chamber refrigerators - 30-50 grams.
• 🔹 Double-chamber (with freezer) - 80-120 grams.
• 🔹 Side-by-Side - 150-200 grams.

The exact quantity is indicated on the refrigerator nameplate (“Charge” or “Charging” parameter). An excess of freon is as harmful as its deficiency! It leads to increased load on the compressor and deterioration of heat transfer.

What to do if the refrigerator does not cool after soldering?

If after repair the refrigerator turns on but does not freeze, check the following:

1. Freon pressure. Connect the pressure gauge to the service port. If the suction pressure (lower pressure gauge) is below 0.2 atm, it means there is not enough freon.
2. The operation of the compressor. Touch it with your hand - if it is cold, the starting relay may be faulty. If it is hot, but does not hum, check the windings with a multimeter.
3. Clogged capillary tube. If the compressor works, but the condenser (grid at the back) does not heat up, then freon is not circulating. purging with nitrogen.
4. Thermostat. Set the temperature regulator to maximum. If the compressor does not turn on, the thermostat is faulty.

If you cannot determine the cause yourself, contact It is possible that another part of the system (for example, a filter drier or valve) was damaged during soldering.

Is it possible to use compressed air instead of freon to check the tightness?

Yes, but with caution! Compressed air can be used for preliminary check tightness, but remember:

• 🔹 The pressure should not exceed 10-12 atm (otherwise the tubes may be damaged).
• 🔹 There should be no moisture left in the system - after checking with air, be sure to vacuum the system before filling with freon.
• 🔹 Do not use oxygen or other flammable gases - this is dangerous!

The best one for testing is nitrogen - it is inert and does not contain moisture. If there is no nitrogen, use dry compressed air (for example, from a compressor with a moisture separator).