How to solder with flux for aluminum

How to solder aluminum: rules and methods for do-it-yourself aluminum soldering

A reliable way to connect wires when laying electrical communications is soldering. Unlike aluminum, copper conductors are easy to tinning. This imposes restrictions on the applicability of materials for electrical installations. But sometimes working with aluminum cannot be avoided. Soldering wires must follow certain rules. But after learning simple tinning methods, you can make the connection yourself.

Soldering aluminum wires

During electrical installation, the metal cores of the cables are connected by soldering. This guarantees reliable contact at the commutation point. However, while it is easy to apply solder to copper wire, coating aluminum conductor is a little more difficult. In addition, it is impossible to directly connect two metals - they form a galvanic couple. When an electric current passes through the twist, it will heat up.

For your information!

When cleaning the core, it is important not to damage the base metal. Notched aluminum can break easily.

The difficulty of soldering lies in the fact that there is an oxide film on the surface of the metal that is difficult to remove. It is formed instantly when aluminum comes into contact with oxygen in the air. This is due to the high chemical activity of the metal. Without the protective film, it would completely react with oxygen. To ensure that the solder evenly covers the wire and holds tightly to it, its surface is cleaned by etching with fluxes or without access to air.

Required materials and tools

For tinning, first of all you will need a soldering iron. For work, take a device with a power of about 60 W. Soldering is carried out in a well-ventilated area: when the flux is heated, toxic fumes are formed. It is advisable to equip the workplace with a hood. In addition, you should prepare the following:

1. Flux, soldering acid or rosin. The latter is diluted with alcohol in a ratio of 3:2.
2. Sharp knife.
3. Pliers, side cutters.
4. Fine grit sandpaper.
5. Electrical tape or heat shrink tubing.

Submerged Soldering

To remove the oxide film from the surface of aluminum, various fluxes are used (F-59A, FTBF-A, F-61A). The use of a certain composition depends on the characteristics of the metal and its further purpose. Soldering sequence:

1. Clean the core from insulation at a distance of 5 cm from the edge. In this case, the knife is held at an angle so as not to damage the core.
2. The metal surface is cleaned with fine sandpaper.
3. Cover the core with flux using a brush.
4. Clean the metal again with a knife.
5. The wire is tinned with a heated soldering iron.

Important!

Solder is applied from the end of the wire to avoid damage to the insulation.

During tinning, the soldering iron is moved back and forth along the wire, clearing the film from the aluminum surface. It will not be possible to coat the core evenly with solder the first time. The procedure is repeated for open areas. After obtaining the desired result, the end of the wire is washed with an aqueous solution of soda (5 tablespoons per 200 ml of liquid) to neutralize active acids. Flux residue under the insulation or solder will corrode the aluminum over time. As a result, the joint will heat up and char.

Tin and rosin

According to the operating rules for electrical installations, soldering of aluminum wires with acids is prohibited. This is due to the fact that the active substances cannot be completely removed. They react with the metal, destroying it. A seemingly reliable connection may break during operation.

Note!

To avoid possible breakage, aluminum is tinned using rosin dissolved in alcohol. However, this method cannot be used in hard-to-reach places.

The liquid mixture is prepared in a shallow metal bath. The viscosity should provide good coverage of the conductor. The depth of the container depends on the diameter of the core.

Tinning sequence:

1. The wire, stripped of insulation, is placed at the bottom of the bath. Pour in liquid rosin. The latter should exceed the metal by 5-8 mm.
2. Using a sharp knife directly in the liquid, scrape off the protective film from all sides of the core. Without air access in the rosin solution, the metal does not oxidize.
3. With a heated soldering iron they begin to tin the wire. The point of contact of the tip with the metal should be in the liquid at a distance of 2-3 mm from its surface. The core is covered around the circumference with gradual pulling out of the wire. When in contact with liquid, the tip will cool greatly. It is necessary to make stops to warm up the soldering iron.

Important!

Tinning in a solution of rosin with alcohol is associated with a lot of smoke - the procedure is performed outdoors or in a well-ventilated area.

When installing electrical wiring, soldering aluminum conductors will not cause any difficulties. To ensure reliable contact, it is enough to tin the metal surface using various fluxes or rosin.

Source: https://VGrafike.ru/pajka-aljuminievyh-provodov-slozhnosti-i-hitrosti/

Soldering aluminum wires using flux - at home

Many people believe that aluminum soldering is done only in a production workshop. Because of this false opinion, people don’t even dare to do it at home. In fact, this is just a misconception. This article is intended to help solder aluminum wires using flux.

Materials and tools used in aluminum soldering

Before you start soldering, you need to stock up on the tools and materials that you will need for your work:

1. Soldering iron. Since aluminum has high thermal conductivity, you need to use a powerful soldering iron to solder it. In the case of two wires, this can be a device with a power of 60 to 100 W, and for large elements from 100 to 200 W;
2. Solder. High temperature, if it is possible to heat the part material to 600 °C, or normal, if this is not possible;
3. Flux. It is used only if it is not included in the solder;
4. Scraper for cleaning aluminum from protective film. A steel bristle brush, sandpaper or abrasive wheel also work well for cleaning. It is impossible to completely get rid of the oxide film, so the above tools are designed to reduce its thickness, which will simplify the operation of the flux.

Solders and fluxes for soldering copper wires with a soldering iron

Solder selection

For soldering aluminum, it is better to choose ordinary soft tin-lead solder - PIC. The main thing is that it contains more than 50% tin, in order to make sure of this you need to look at the number following the name, it must be more than 50 (POS 50, POS 61, POS 90, etc.).

In addition to the above solders, you can use those based on silicon, copper, aluminum or silver. These include 34A and TsOP-40, which contain zinc, which increases their strength coupled with corrosion resistance.

Solder POS-61 0.8 mm

Flux selection

For soldering aluminum at home, it is better to choose liquid flux, as it is more convenient to use, is well suited for these purposes and can be bought at any electronics store. For aluminum, a metal that is covered with a protective film, you need to choose a special flux, because a regular one will not dissolve the oxide. Among them we can distinguish such substances as: F-61A, F-59A, F-64.

It would also be a good option to make a special composition suitable specifically for this metal.

FDA flux for aluminum soldering

Instructions for soldering aluminum

The process of soldering aluminum parts, if all the necessary materials are available, is not much different from soldering copper or steel. It consists of:

1. Surface preparation, which includes degreasing the material using a solvent , such as gasoline, and reducing the thickness of the oxide film;
2. Arrangement of parts in the desired position. At this stage, it is advisable to fasten the parts so that they are fixed and after applying solder you do not have to redo everything again;
3. Heating the joint using a soldering iron. Its power should be about 100 W. You can also use a gas burner. In this case, it is very important not to melt the base material;
4. Applying solder to the joint. It is rubbed in after applying flux to the junction of two parts. The flux itself is applied to the joint with a brush, which usually comes with the jar. If it is already contained in the solder, you just need to touch its rod to the junction of the preheated parts.

Blitz tips

• Tin solder easily becomes rusty , so when using it, it would be a good idea to apply a paint coating.
• In addition to conventional solder, the melting point of which is relatively low, you can use high-temperature solder , for example, “Aluminium-13” which consists of: aluminum - 87%, silicon - 13%. To be able to use it, you need to be able to heat the parts being fastened to a temperature of 600 °C.

Source: https://orcmaster.com/instruments/pajka-alyuminievyx-provodov.html

Rod for soldering aluminum at home / Tools / iXBT Live

Hi all! Many people know that aluminum is soldered mainly in an argon atmosphere with a special welding machine, but there is also an option for working with a gas torch, and even a turbo lighter can be used on a small scale.

In general, this is not my first acquaintance with this wire, but the shopping experience is not very good, so I will share not only the test result, but also trusted places to buy so as not to get sample No. 2 , but let’s start in order.

• Characteristics
• Unboxing and appearance
• Testing
• Results

Characteristics

Diameter: 2.0 mm
Length: 500 mm
Soft solder ISO 3677: ~B-Zn98Al 381-400
Approximate composition (weight%): 2.4 Al – rest Zn
Melting point ºС: 360
Tensile strength (MPa): Up to 100 (Al)
Density (g/cm3): 7.0

Unboxing and appearance

The last and most profitable purchase was sample No. 3 from banggood.

Came in a small gray package

The rod is additionally packaged in a transparent zip bag.

5 meters cost me $8 with points, that is $1.6 per meter - go to the store

White powdery flux is visible in the center, the rod is moderately hard, looks like aluminum without oxidation

Comparison

The first one I bought was the leftmost sample No. 1 from Ali. Its properties are absolutely identical to sample No. 3 , but 3 meters cost me $12 , that is, $4 per meter , which is almost three times more expensive. check current price

In the center is sample No. 2 . It costs $5 for 3 meters or $1.7 per meter , like sample No. 3

But as soon as you take the bag in your hand, you realize that this is a POS with not very thick flux inside.

don't buy here

Two more samples at $8 for 3 meters were never delivered, they were probably not even sent.

Testing

Over time, aluminum becomes covered with an oxide film, due to which the surface becomes dull, so, before soldering, the surfaces must be cleaned to a shine, otherwise the solder will simply roll off in balls on the surface, regardless of the degree of its heating. Sample No. 1

 In general, it is correct to heat the part to a temperature of about 400 degrees, and then simply move the rod, which will melt and fill the cracks, but I have little experience, so in order not to overheat the surface, I periodically bring the rod into the burner flame. If the temperature is low, the solder will roll down the surface like a ball; if it is sufficiently high, it will tin it.

 The fracture test shows a good result - the break does not occur along the seam

Sample No. 2 . It melts very well, emits a lot of smoke, and smells like burnt “aspirin.” It sticks to aluminum, but if you overheat it, it burns out pretty quickly.

It is inconvenient to work due to the stench and the need to control the temperature.

Sample No. 3 . I decided to solder the tubes with the outer walls

We try to break the seam. After the tube came out of the vice, I clamped it higher, bringing it out of focus and only noticed this at the stage of creating GIFs

But there is a photo of the result which shows that the seam was not damaged.

And finally, let’s splice the aluminum tube with a piece of duralumin.

 The tear test was also successful.

Results

An interesting wire - aluminum solders perfectly, filling even small gaps, the main thing is that the joints are not dirty. It also sticks well to copper, but experienced people say that it is better to use other alloys to work with it, although this rod is quite suitable for emergency field repairs.

The melting point of aluminum is about 660ºC, it would seem that you can use rods at 450-500 degrees, but you may encounter two problems:
1. A massive part needs to be heated up to 500 degrees with something else
2. You can overheat the soldering area and ruin the part

Sample No. 3 seemed to me the most optimal .
It corresponds to the declared characteristics and costs at least half as much as the others. There are also lots of different lengths to choose from: 1 meter - $2.89
2 meters - $4.39
3 meters - $6.39
5 meters - $9.89

go to the store

Source: https://www.ixbt.com/live/instruments/prutok-dlya-payki-alyuminiya-v-domashnih-usloviyah.html

How to solder aluminum with a soldering iron - select solder, flux, rosin, soldering iron or burner

Soldering wire connections with solder is considered the most reliable method of connecting wires and cable cores. It’s good if you only need to solder copper wires, which are easily tinned with solder. It’s not for nothing that in electronics all terminals of elements are copper and tinned.

Soldering aluminum at home

Once solid wires and stranded cable strands are tinned, they are fairly easy to connect by soldering. How to solder aluminum with tin if the solder is rejected by aluminum oxide. As you know, aluminum is coated with a thin layer of oxide, which instantly forms on aluminum upon contact with oxygen. In order for the solder to adhere well to the aluminum wire, you need to remove the aluminum oxide and then tin it.

For this purpose, the following fluxes exist: soldering acid, special fluxes for aluminum, and a mixture of rosin and acetone. All these advantages destroy or hinder the formation of an oxide film on aluminum. After using this type of flux, the process of tinning aluminum is simplified.

The necessary tools for soldering aluminum with tin are: an electric soldering iron, a sharp knife, pliers for twisting wires, a small file for preparing the soldering iron tip. The materials you will need are: POS 61 or POS 50 solder, flux for soldering aluminum F-64 or similar, sponge.

Soldering aluminum with tin and flux F 64

Flux F 64 is intended for soldering aluminum. The soldering technique is not complicated. First of all, you need to remove 5 cm of insulation from the wires. The insulation is removed with a sharp knife at an angle to the wire so as not to cut it. Notched aluminum breaks off easily.

Tools and materials for soldering aluminum wire

Next, you need to thoroughly clean the wire with fine sandpaper or a sharp knife. Having stripped the wire, it is moistened with a brush with a plus and with a sharp knife they continue to strip the wire, but now under flux. In this way, the oxide film of the aluminum wire is removed, preventing it from oxidizing again in air. Next, using a heated soldering iron with solder, begin tinning the wire from its end.

If you start tinning the wire near the insulation, then you can burn it. In this case, the insulating properties of the wire will be lost. The wire is tinned with a soldering iron, moving back and forth, while the oxide film is removed from the aluminum. It is not possible to tin the wire straight away. Therefore, flux is again applied to the non-tinned sections of the wire and sections of the remaining oxide film are removed with a hot soldering iron with solder and movements back and forth and serviced.

In this way, the aluminum wire is completely covered with solder. After tinning, the aluminum wire is dipped in a soda solution (5 tablespoons per 200 grams of water) and the remaining flux is washed off with a toothbrush. The flux contains active acids that not only corrode the film, but also the wire itself. Therefore, the remaining flux must be washed off. It will not be possible to wash it off completely, since it partially remains under the solder and eats into the wire.

But at least partially it needs to be washed off. Copper wire is not treated with F 64 flux; it is better to use a solution of rosin and alcohol (50% to 50%). Using a brush, apply liquid rosin to the copper wire (having previously stripped it) and use a hot soldering iron to service the wire, starting from the end. The soldering iron tip should be smooth and clean. The shells at the end of the soldering iron tip are removed with a fine file.

And the remains of burnt solder (slag) are wiped off with a sponge or rag. Once the aluminum and copper wires are tinned, they are twisted with pliers, liquid rosin is applied with a brush and the connection is soldered, also starting from the end. If you connect aluminum without tinning with solder, the connection may break down over time. The aluminum-copper connection is a galvanic couple, and when current passes through it, it heats up and destroys the connection.

Table of temperature conditions of solder brands

As a result, the twisted area becomes very hot and charred, which increases the fire hazard. Tin solder is neutral to aluminum, so aluminum wires must be tinned before connecting to copper. POS 61 and POS 50 solders with a low melting point of 190 - 210C are well suited for soldering aluminum wires.

Soldering aluminum with copper, tin and rosin

Soldering electrical wires using soldering acid is prohibited in the PUE. This is due to the fact that this acid does not burn completely during soldering. As a result, the junction of the wires is corroded by acid over time, oxides are formed, which heat up when current passes and can cause the insulation to catch fire. These acid-containing fluxes include special fluxes for soldering aluminum, including F 64.

So how to solder aluminum with copper so that the connection is high-quality and durable. In terms of complexity, the method of tinning aluminum with tin and rosin is even easier than tinning aluminum with F 64 flux. But the quality and reliability when tinning with rosin will be high. When tinning aluminum in rosin, you need to make or select a low bath for liquid rosin (rosin 60% and alcohol 40%).

Fluxes for aluminum soldering

Fill the bath with liquid rosin so that the wire is buried in it with 5-10 mm of insulation. The wire, stripped of insulation, is placed in rosin and with a sharp knife (conveniently a scalpel) the oxide film is removed from the aluminum wire without removing it from the bath. That is, under rosin they protect the wire along its entire length from all sides. Under the rosin, a film does not form on the cleaned areas of the aluminum wire, since there is no contact with oxygen.

Now take a heated soldering iron with solder with a power of at least 60 W and lower it onto the bare and free of oxide wire, right at the surface of the rosin, little by little scroll and pull out the already tinned sections of the wire. The essence of the method is that the wire is tinned at the very surface of the liquid rosin. So that the stripped sections of the wire from oxide cannot come into contact with air.

The soldering iron can be immersed 2-3 mm in rosin at times. After tinning the wire a little, lift the soldering iron so that it heats up again. Yes, at the beginning, there will be a lot of smoke, so it is better to learn to solder outdoors or in a room with good ventilation. After several attempts, you will develop your own tinning technique and gain a little experience.

You will decide on the position of the soldering iron, the speed of tinning the wire will increase, that is, skill will appear, and the amount of smoke will decrease. But the wire will be perfectly tinned. Next, as usual, twist the wires and solder them with a small amount of solder.

The remaining rosin on the soldered twisted wires is washed off with a brush and alcohol. The disadvantage of this method is the impossibility of soldering in hard-to-reach places. For such cases, it is better to use other methods for safely connecting aluminum to copper.

We solder aluminum | DIY master class

There are situations when it is necessary to solder aluminum products. But due to the fact that the oxide film covers the surface of the aluminum, the solder simply does not stick to it. Solders and fluxes have now been developed specifically for this purpose. But we will try to cope with this task in the old fashioned way.

Attention!
Work should be done in a well-ventilated area, preferably equipped with active ventilation, or outdoors. To solder aluminum, we need machine oil (used to lubricate sewing machines), a small piece of sandpaper, rosin and regular solder for soldering radio components.

You need a soldering iron that is as powerful as possible. For example, this one. Its power is 65 W.

We will solder the bottom of an aluminum beer can.
Before work, the soldering iron tip must be leveled with a file (remove all shells) and tinned.

Use a piece of sandpaper to clean the soldering area until it shines.

Pour some oil on this place.

Next, rub the oil stain with sandpaper.

By doing this, we remove the oxide film, and the oil prevents the formation of a new film. By this time, the soldering iron must be heated to operating temperature.

We dip the soldering iron tip into rosin, pick up as much solder as possible, dip it into rosin again and begin to quickly rub the future soldering area with little effort. At the same time, the oil begins to burn out profusely. Therefore, we do not regret rosin. If everything was done correctly, then a layer of tin should cover the surface of the aluminum.

Sometimes, to achieve the desired result, you will need to repeat this operation several times.

Copper wire is soldered to tinned aluminum very easily.

Now let's try to tin and solder the aluminum wire. We remove the insulation from it and clean it until it shines. Pour machine oil onto the tinned bottom of the jar.

Next, the wire needs to be dipped in oil and rubbed with sandpaper.

Then we try to tin the wire right in the bottom of the can. If it works, then everything was done correctly. If not, we work again with sandpaper.

The wire is also perfectly soldered to the aluminum can.

Instead of machine oil, you can use gun oil. If the aluminum part is large, it may need to be heated additionally. For example, on an electric stove.

Source: https://ice-people.ru/payal-2/kak-payat-alyuminij-payalnikom-podbiraem-pripoj-flyus-kanifol-payalnik-ili-gorelku.html

Soldering aluminum at home with a soldering iron and gas torch: solder and flux

Soldering aluminum is a rather difficult task. Basically, soldering aluminum parts becomes more difficult due to the appearance of a chemically resistant oxide on the metal surface.

In addition, due to the relatively low melting point and low temperature of loss of strength, it is quite difficult to heat aluminum without causing destruction of the entire product. Therefore, soldering aluminum parts is difficult if conventional consumables are used.

At the moment, soldering of aluminum products is carried out using specialized fluxes and solders.

Process Features

The key problems of soldering aluminum with traditional solders and fluxes are related to:

• the formation of an oxide film with a high melting point and good chemical resistance, preventing interaction with tin or lead solders;
• low melting point of pure metal, making high-quality soldering difficult.

To solder aluminum parts, specialists must clean the surface of the material from the oxide film or use specialized aggressive solders and fluxes.

Soldering aluminum with a soldering iron should be done using zinc solders. This option for low-temperature soldering of aluminum, unlike cadmium, bismuth, tin or indium, interacts well with pure metal and forms a strong seam.

Melting temperature of aluminum products for soldering.

The basic rules for soldering aluminum at home in the absence of zinc or aluminum solder include the following points:

1. Pre-cleaning of the surface.
   The area where soldering work needs to be performed should be carefully cleaned of paint, dirt and particles of other metals.
2. Grinding.
   For better adhesion between the solder and aluminum, the area of ​​the intended connection should be sanded.
3. You should not take a long break between cleaning aluminum and directly applying flux.
   Due to the high rate of oxide formation on the surface, the cleaning process for aluminum may need to be repeated.
4. The correct choice of device for heating the soldering area.
   Electric soldering irons with adjustable tip temperatures are ideal for this work.
5. Monitoring the temperature of the connection point.
   Due to the good thermal conductivity of the metal, the temperature will quickly spread over the entire area of ​​the product, and therefore the soldered area will quickly cool down.
6. A prerequisite for successful soldering of aluminum is tinning the area of ​​the intended contact.
   If a drop of solder is applied to the cleaned area of ​​aluminum in time, an oxide film will not be able to form.

There are several secrets that can be used to solder aluminum without specialized solder:

1. Destruction of the oxide film by intense friction of the joint with a brick.
   After a certain amount of dust has peeled off the stone, you should put the required amount of rosin or flux on the soldering iron tip and fill the soldering area. After this, you should make strong pressure movements with the flat cut of the soldering iron at the place of the planned soldering. With this simple action, brick dust will destroy the thin oxide film, and the solder on the soldering iron will tin the cleaned metal.
2. Destruction of the oxide film using iron particles.
   To do this, grind off a thick nail with a file, apply a large amount of liquid rosin or flux to the soldering area, and then add metal filings. After the soldering agent has hardened, you should put solder on the tip of the soldering iron and press it firmly into the soldering area.
3. Use of transformer oil.
   To implement this method, remove the top layer of the part with sandpaper, and then pour oil onto the cleaned area. After this, you can rub in the heated solder and get good adhesion between the tin and aluminum.

Necessary materials and available tools

Soldering of aluminum products with proper surface preparation can be performed with all types of solders. For example, soldering aluminum with tin is possible by removing the oxide film.

Materials required for soldering aluminum.

However, in most cases, aluminum joints obtained by soldering with tin solder have low reliability due to the poor solubility of the materials.

The most optimal solders for soldering aluminum are:

• zinc;
• copper;
• silicic;
• aluminum.

There are a large number of solders on the market based on the above materials. One of the most common zinc solders is TsOP40, which contains 40% zinc and 60% tin. In addition, 34A solder remains popular, consisting of 66% aluminum, 28% copper and 6% silicon.

Special mention should be made of special solder for low-temperature soldering of aluminum parts. One of the most common consumables for such an operation is HTS-200 solder.

Of course, we should not forget about the mandatory use of a special flux for low-temperature soldering of aluminum.

The flux for trouble-free soldering of aluminum must contain at least one of the following elements:

• triethanolamine;
• zinc fluoroborate;
• ammonium fluoroborate.

One of the brands of fluxes for welding aluminum with a gas torch is F64. The popularity of this flux is due to its high activity. Even aluminum parts can be soldered with F64 flux without first stripping the oxide film.

The F64 flux composition includes:

• 50% potassium chloride;
• 32% lithium chloride;
• 10% sodium fluoride;
• 8% zinc chloride.

Preparing parts

Soldering aluminum at home involves careful preparation of the part.

As a rule, qualified craftsmen perform the following procedures before soldering aluminum with their own hands:

1. Degreasing the surface.
   The most suitable substances for high-quality degreasing of the soldering area are acetone, gasoline and solvent.
2. Removing the oxide film.
   This procedure is carried out using a grinding machine or a homemade wire sponge. In rare cases, specialists use film etching using chemicals, such as acid.

After completing all the preparatory procedures, you can proceed to direct soldering of aluminum at home.

Technological approaches for aluminum soldering

The technology for soldering aluminum with flux is practically no different from joining other metals.

The entire process of soldering aluminum with solder can be divided into the following stages:

1. Surface preparation.
   Before soldering aluminum, the parts to be joined should be cleaned and degreased.
2. Installing the product into working position.
   This step may require a vice or a third hand.
3. Applying flux to the soldering area.
4. Warming up the product using an electric soldering iron or gas torch.
5. Apply solder or solder paste to the required areas.
   Zinc or copper solders are suitable for this role. Sometimes high-temperature solders may be needed to ensure good mechanical fixation of the product.

Scheme for soldering aluminum pipes.

It is important to remember that when soldering with flux-free solder, you should make striking movements with the soldering iron in order to ensure interaction between the components of the solder and the metal.

Carrying out work using a special soldering iron with a scraper will give good results in the following cases:

• soldering of aluminum utensils;
• soldering aluminum wires;
• seal surfaces not subject to strong mechanical loads;
• connection of small parts.

Soldering of massive aluminum parts and thick rods should be carried out using welding or a torch. Welding is not always suitable due to the high temperature of the arc, which melts the metal. Therefore, most specialists prefer to use burners.

The best effect is achieved with continuous soldering with a torch. If, for some reason, the soldering process had to be stopped, the entire seam should be completely heated in order to ensure uniform distribution of the solder and get rid of unsoldered areas.

The process of soldering aluminum rods using a torch is divided into the following stages:

1. Cleaning metal from dirt and preparing the surface by grinding.
2. Heating the entire surface of massive products using a burner.
3. Remove all flammable materials from the work area.
4. Turn on the hood to neutralize the caustic fumes of solder.
5. Preparation of solder wire.
6. Preparation of flux grades F-59A, F-61A or F-64A.

It is allowed to heat the metal to a bright orange color. In this form, the metal does not melt, and the solder is applied as evenly as possible.

The most complex and at the same time high-quality method of joining aluminum products is welding. This method is difficult due to the low melting point of the metal.

Qualified specialists most often weld aluminum products using the following methods:

• welding using coated electrodes;
• welding using shielding gas.

The first welding option has the following disadvantages:

• low weld strength;
• strong splashing of metal during cooking;
• poor separation of slag from the seam.

Welding in an inert gas atmosphere has no noticeable disadvantages and is considered the best method for joining aluminum parts.

Heating an aluminum product

The heating method for aluminum parts is selected individually. Products of relatively small sizes can be heated with an electric soldering iron and tinned with solder and flux for soldering copper. For more massive parts, it makes sense to use another method of soldering aluminum using a gas torch or blowtorch.

Table of solder brands for aluminum soldering.

When warming up the part, you should:

1. Control the temperature of the heated product.
   You can find out the current surface temperature of a part by touching it with a solder rod. When the aluminum solder wire begins to melt, reduce the heat and begin direct soldering using active flux.
2. Watch the burner flame.
   The burner jet contains a mixture of natural gas and oxygen, and therefore should be bright blue. The correct composition of the burner flame allows the aluminum part to oxidize less and not overheat.

The key advantages of heating massive aluminum products with a gas burner are presented:

1. Low cost of equipment.
   A gas burner consumes a small amount of fuel and is sold at any hardware store.
2. Absence of uneven heating and stress inside the product.
   Parts heated by a gas burner have an even seam and do not change geometry due to overheating.
3. Easy control of operating temperatures.
   If the metal heats up too much, reduce the intensity of the burner flame.
4. Possibility of soldering work at home.
   When the metal is heated with a burner, there is no pungent odor, there is no ultraviolet irradiation of the skin and no sparks fly.

Conclusion

Soldering aluminum with flux is a rather non-trivial task. When connecting aluminum products, certain standards must be observed, and the surface of the part must meet numerous requirements. If the technological process is not followed, the welded or soldered seam will crack and fall apart.

Aluminum welding technology depends on the massiveness of the product. Small parts, such as wires or dishes, can be easily repaired with an electric soldering iron, but large rods or pipes should be heated with a gas torch or blowtorch.

Source: https://tutsvarka.ru/vidy/pajka-alyuminiya

Principles of aluminum soldering

Soldering aluminum is a complex process, since an oxide film forms on the surface, which interferes with the work. Therefore, it is necessary to use special techniques to simplify the workflow. Special fluxes will allow you to get rid of the negative factors of the oxide layer.

Materials used

To complete the work you will need to prepare the following materials:

To obtain high-quality seams, you need to use a flux for soldering aluminum based on zinc, silicon, and copper. The joints are strong, durable, resistant to corrosion, static and dynamic loads.

Solders with the following markings are suitable for soldering aluminum:

• TsOP-40 - refractory tin-zinc composition;
• POS - light alloy solder;
• 34A - alloy based on copper and silicon;
• “Aluminium-13” is a foreign analogue of 34A.

The use of flux improves the adhesion of metal to solder, resulting in a strong connection. The durability of the seam, the strength characteristics of the product, and the resistance of the material to the negative influences of the external environment depend on its choice. Fluxes contain active elements: zinc or ammonium fluoroborate, triethanolamine.

Solder fat comes in the following types:

• neutral based on rosin and stearin - it is thick, capable of removing small contaminants, and adheres well to the surface of the metals being welded;
• active with a complex chemical composition - effectively removes oxides and traces of corrosion, increases soldering properties.

The fat contains zinc and ammonium chloride, paraffin, and auxiliary substances.

Solder fat has the following advantages:

• easy tinning due to spreading in a thin layer;
• availability;
• dosage accuracy;
• no traces after use.

It is recommended to use the following brands of fluxes: F-64, F-61A, F-59A, 34A, F-5, F-124.

Scope of the process

Brazed aluminum products are used in the following areas:

• automotive industry;
• radio electronics;
• production of window frames;
• production of bicycle parts;
• creating frames for greenhouses and equipment buildings.

Soldering methods

There are the following soldering methods:

• with rosin;
• with solder;
• electrochemical.

With rosin

Step-by-step implementation of the method:

1. The soldering iron is warming up.
2. The tip is tinned to remove dirt or carbon deposits.
3. Rosin is applied to the joint seam and melted with a soldering iron.
4. After melting, use a sting to rub the surface until the oxide film is removed. At the same time, tinning occurs.
5. After the process is completed, the elements are joined, heated to the melting point, and then left to cool.

Using solders

The method using solder for soldering aluminum is implemented as follows:

1. The joining surfaces are cleaned mechanically.
2. The parts are securely fixed.
3. Local heating of the structure is performed.
4. The rod with solder is guided along the joint seam, simultaneously heating it with a burner until it melts.

If solder without flux is used, it will need to be used separately. It is pre-applied in an even layer on aluminum.

Electrochemical method

Step-by-step electrochemical soldering of aluminum:

1. The surface is cleaned of dirt, partly of the oxide film, mechanically.
2. Apply a thin layer of copper sulfate.
3. The negative electrode of the current source is connected to the part.
4. The positive electrode is connected to a high purity copper wire (diameter greater than 1 mm). It is located above the structure on a special stand, ensuring contact only with the treated area.
5. The power source turns on. The electrolysis process begins to take place.
6. After removing the oxide film, the wire is removed, and the parts are heated with a soldering iron to the melting temperature or solder is used.

To ensure high quality soldering, it is necessary to apply galvanic coatings with special tools. They will allow for uniform copper plating.

General principles of soldering aluminum at home

Basic principles of soldering aluminum at home:

• it is necessary to perform high-quality cleaning of the metal surface from contaminants, coatings, and oxide films;
• the time interval between cleaning and soldering should be minimal;
• to remove the oxide film, it is better to use metal brushes or soldering irons with special attachments;
• the choice of heating tool is made depending on the soldering area, since aluminum cools quickly due to its high thermal conductivity;
• if there is no suitable solder, then it is allowed to use any solder that contains tin or lead;
• when heating parts for applying solder, it is important not to overheat aluminum, since it has a lower melting point compared to the oxide film;
• tinning the aluminum surface with a continuous layer will eliminate the appearance of oxides, which will simplify its soldering;
• when using a burner, it is important to follow fire safety rules, especially when applying degreasing solvents;
• soldering can be performed in several layers, before applying each you need to wait until the previous one hardens;
• the use of flux will require the use of protective equipment, since it may contain caustic substances;
• the burner flame should always be directed in the direction opposite to itself;
• For soldering, it is recommended to use soldering irons with a power of more than 100 W;
• flux is used mainly for elements with a thickness of 4 mm or more or surfaces with complex shapes;
• The composition of the solder is selected based on the type of soldering, but the melting point is always lower than that of aluminum;
• to solder workpieces with a thickness of more than 4 mm, along the edge of the butt seam you need to cut the edge at an angle of 450 to increase the contact surface;
• After carrying out the work, it is necessary to ensure the integrity, strength, and uniformity of the seam.

When choosing solder, you need to consider the type of tool used for melting.
Alloys with low melting points are suitable for a soldering iron: tin alloys with copper, zinc, bismuth. To create a refractory compound, you will need a complex alloy of aluminum, copper, and silicon. Verified! Soldering aluminum at home

Principles of aluminum soldering Link to main publication

Source: https://metalloy.ru/obrabotka/pajka/alyuminievyh-izdelij

DIY soldering with flux for aluminum

Quite often you can hear the opinion that aluminum alloys and aluminum itself are quite difficult to solder. However, this opinion will be valid only if the same fluxes and solders are used for it as for copper, steel and a number of other materials. Today you can find special materials on sale that were developed directly for soldering aluminum. As a result, it became as possible to solder it as copper.

The difficulty of soldering aluminum when using standard solders and fluxes lies in a number of chemical and physical properties of such a material. First of all, it should be noted that on the surface of this metal there is always a fairly strong oxide film, which is also capable of well resisting the effects of a wide variety of chemical compounds.

The oxide film prevents solder from contacting the metal surface directly. To overcome it, they resort to one of 2 methods:

1. Mechanical processing , due to which the film is removed from the surface of the wire, after which it can begin to be soldered.
2. The use of strong fluxes , which simply dissolve it and expose the surface of pure metal.

The difficulty when soldering aluminum also lies in the fact that this metal has a low melting point, which is only 660 degrees. The strength of the wire when heated to 250-300 degrees becomes significantly lower, which is why it becomes unstable.

Soldering temperature should be between 500 and 640 degrees. This is not too long an interval, especially if you plan to use high-temperature soldering, where there is a very high probability of overheating of the material, after which the wire melts.

Unlike almost all metals used in low-melting solders:

• lead;
• cadmium;
• bismuth;
• antimony, etc., aluminum has the characteristic of low mutual solubility. This leads to the fact that the strength of the joints obtained as a result of soldering leaves much to be desired.

What to use?

The choice of flux for aluminum depends on a number of important factors. In particular, the most popular is the so-called binary flux, which is a solution of concentrated phosphoric acid.

It has a large number of positive aspects:

1. This composition is no-clean , that is, it will not require additional washing after completion of soldering work.
2. It acts very quickly , so you can start soldering almost immediately after applying it to the surface of the wire.
3. The substance is universal , therefore it is suitable for a number of other metals, in particular steel or copper.

To make aluminum soldering as good as possible, you need to use solders that contain aluminum, silver, silicon, zinc and copper. You can find consumables on sale that contain all these materials.

When choosing solder, take into account that the connection will have the highest ability to resist corrosion processes if the solder contains a large amount of zinc.

It is quite acceptable to use solders made on the basis of lead and tin for soldering aluminum , but here it will be impossible to do without either mechanical stripping of the material or without the use of reliable fluxes. It is not recommended to use this type of solder as aluminum will not bond to it reliably. Another negative point is the susceptibility of the connection to corrosion.

To solder aluminum, you should purchase only high-temperature solders, without which it will be quite problematic to achieve a high-quality connection of wires.

In addition to solder and flux, you will need a soldering iron. The width of the tip here will directly depend on how large the cross-section of the wire is - the higher it is, the wider the tip should be selected. It is worth noting that soldering irons with unregulated heating temperatures are now gradually becoming a thing of the past.

They are being replaced by so-called soldering stations. These products are good because they have a temperature regulator for heating the soldering iron tip, as well as a whole set of these replacement tips. When working with a material such as aluminum, this is a very useful point. On the display you can set the required temperature to the nearest degree and get to work.

How to solder?

Before proceeding with direct soldering, it is necessary to properly prepare the surface of the wires. First, the surface must be degreased. This is achieved by treating the soldering area with acetone, gasoline or another type of solvent.

If there is no flux on hand, it is necessary to mechanically remove the oxide film from the surface of the wire. This is done using sandpaper, a steel brush, etching fluid, and so on.

It must be remembered that it will not be possible to remove the abrasive film by mechanical means, since a new, albeit thinner, oxide film immediately forms on the metal surface due to contact with air. Flux is much better in this regard, as it removes all the oxide film and prevents air from penetrating the metal.

When the oxide is removed, the wires are fixed, heated with a soldering iron and solder is applied to the heated area.

Soldering aluminum at home: features of the process, types of flux and solders, how to solder a pipe

Aluminum and its alloys have very good characteristics, such as high thermal and electrical conductivity, ease of processing, low weight, and environmental safety. But this beautiful metal has one very big drawback: it is extremely difficult to solder. A properly selected flux for soldering aluminum helps solve this serious problem.

The problem with soldering aluminum is due to its chemical structure. This metal itself is chemically very active; it reacts with almost all chemicals.

This causes pure aluminum to instantly react with oxygen in air. As a result, a very thin and at the same time extremely strong oxide film is formed on the metal surface: Al2O3.

In terms of their properties, aluminum and its oxide represent two extreme opposites combined into a single whole. For example :

• The melting point of pure aluminum is 660 degrees. Aluminum oxide, or corundum as it is also called, melts at a temperature of 2600 degrees. Refractory corundum is used in industry as a refractory material.
• Aluminum is a very soft and ductile metal. Corundum has extremely high mechanical strength, which makes it possible to produce all kinds of abrasive materials from it.

Aluminum oxide turns ordinary soldering into a rather complex process. For its successful implementation, it is necessary to use specific methods and special aluminum solders and fluxes.

Metal soldering

The meaning of soldering any metal is that a special substance called solder is introduced into the space between the parts being soldered in a molten state. After hardening, the solder reliably binds two metal parts into a single whole.

When soldering aluminum, the oxide film on its surface prevents the molten solder from connecting to the metal. In other words, adhesion is impaired, and therefore the solder cannot spread over the surface of the metal and stick to it . This makes soldering aluminum almost impossible without the use of special means that partially remove the oxide from the metal surface and promote normal adhesion.

Removing oxide film

Removing oxide from the surface of aluminum is a complex process and never leads to a final result. That is, the oxide film is practically impossible to remove, since instead of the one just removed, a new one is instantly formed. It is possible only with the help of specific means to weaken its effect. This can be done using two different methods :

• Chemical method. With the help of special aluminum fluxes, the film is destroyed as a result of exposure to active acids.
• Mechanical method. Through the use of abrasive tools, the integrity of the film is damaged.

In practice, both of these methods are most often combined to achieve the maximum possible effect.

Fluxes for aluminum

Flux is used to remove oxide from the metal surface and subsequently prevent the formation of a new film. It must be remembered that during the soldering process, the flux should not interact with the solder and enter into chemical reactions with it. Fluxes can be in different states :

• Liquid.
• Paste.
• Powder.

For aluminum, liquid fluxes based on orthophosphoric acid are most often used . There are so-called no-clean fluxes, the use of which does not require subsequent washing of the soldered surfaces under running water.

However, most often aluminum fluxes contain highly toxic substances that are unsafe and, from an environmental point of view, can severely corrode the metal at the soldering site. Therefore, the use of fluxes requires thorough washing of the soldering area under running water.

The industry produces a larger number of aluminum fluxes, among which the following can be distinguished::

• F-64. Highly active flux for aluminum and its alloys. It is considered the best flux for this metal. High activity is determined by the high content of active fluorine in its composition, about 40%. When heated, fluorine destroys the oxide film on the surface of aluminum. The use of this flux requires thorough washing of the welded surfaces after the process is completed.
• F-34A. Special aluminum flux for refractory solders. Ingredients: potassium chloride 50%, lithium chloride 32%, sodium fluoride 10%, zinc chloride 8%.
• F-61A. It is used with conventional lead-tin solders, melting at a temperature of 150−350 degrees. Composition: zinc fluoroborate 10%, ammonium fluoroborate 8%, triethanolamine 82%. Used for soldering dissimilar metals, such as aluminum and copper. Therefore, when the question arises of how to solder aluminum to copper, this flux will be the answer.
• NITI-18 (F-380). Suitable for refractory solders with a melting point of 390 - 620 degrees. The peculiarity of this flux is that, while dissolving the oxide film well, it has virtually no effect on the base metal. After finishing soldering, flux residues must be removed immediately. To do this, the soldering area is first washed with hot running water, then with cold water. And finally, incubate for 15 minutes in an aqueous solution of phosphoric anhydride.
• A-214. Universal no-clean flux of medium activity. Application temperature 150−400 degrees. It does not contain harmful salts of aniline, phenol or carboxylic acids, therefore, thorough rinsing is not required after use. Residues can be easily removed with a paper towel soaked in alcohol.

Mechanical oxide removal

To facilitate the dissolution of the film using flux, it is first partially removed using mechanical methods. These techniques make it possible to only slightly weaken the effect of the oxide, since it was experimentally established that the newly formed film is somewhat inferior in strength characteristics to the old one. For these purposes the following devices are used :

• Sandpaper.
• Files and rasps.
• Hard metal brushes.

The process of mechanical removal of surface oxide can be optimized using brick dust. The soldering area is first sprinkled with fine brick chips . Then:

• A large amount of dry rosin is poured onto the brick crumbs.
• With a preheated soldering iron tip, the rosin is melted and distributed over the metal surface in an even layer.
• With the tinned tip of the soldering iron, they begin to vigorously rub the soldering area. In this case, the brick chips peel off the oxide film, and the molten rosin prevents the penetration of oxygen instead of soldering and therefore a new oxide film does not form.
• The result is a well-tinned aluminum surface.

As an abrasive, with the same effect, you can use sifted river sand or metal filings.

Soldering aluminum

The basis of any soldering is the so-called tinning or tinning. In this process, solder is distributed evenly over the surface of the metal. In order for tinning to go well, two important components are needed: a special flux and properly selected solder. We have already looked at fluxes, now it’s the turn for solders.

Special solders

Conventional solders used for soldering non-ferrous metals contain tin and lead. The question of how to solder aluminum with tin is not relevant, since such solders are not recommended for aluminum, because it is practically insoluble in these metals. Special solders are used that contain a fair amount of aluminum itself, as well as silicon, copper, silver and zinc.

• 34-A. Special refractory solder for aluminum. Melting point 530−550 degrees. Composition: aluminum 66%, copper 28%, silicon 6%. It is recommended to use it together with the corresponding flux F-34A.
• TsOP-40. Belongs to the category of tin-zinc solders. Composition: zinc 63%, tin 36%. Melting occurs within 300−320 degrees.
• HTS 2000. Special solder for aluminum made in the USA. Main components: zinc 97% and copper 3%. Melting point 300 degrees. Provides a very strong connection, comparable in strength to a weld seam.

The presence of a metal such as zinc in the solder provides it with high strength characteristics and good resistance to corrosion. The presence of copper and aluminum increases the melting point and makes the solder refractory.

The use of one or another solder is determined by the tasks facing the parts being soldered. Thus, for soldering large-sized and massive aluminum parts, which will subsequently be subjected to heavy loads, it is better to use refractory solders; their melting temperature is comparable to the melting temperature of aluminum itself.

When the question arises of how to solder an aluminum tube, you need to understand exactly what this tube will be used for in the future. Refractory solders are characterized by high strength, and the large mass of the part allows for good heat dissipation during the soldering process, which will prevent the destruction of the aluminum structure due to its melting.

DIY flux for soldering aluminum

People learned to solder metal products back in ancient times, as soon as they learned to smelt tin and lead. Of course, the simplest way to fasten metal products to each other is to use a regular bolt with a nut, because this does not require their preliminary preparation, the use of various solders, fluxes, etc. However, metal soldering is widely used both on an industrial scale and at home.

Before you start soldering, the surface of the parts to be joined is cleaned with sandpaper or a file and lubricated with flux. The heated soldering iron is immersed in ammonia or rosin to clean it of metal oxides, after which the molten solder is transferred to the soldering site.

As for aluminum or its alloys, rapid oxidation of the soldered surface occurs here, and conventional soldering methods do not give the expected result. The fact is that the surface of aluminum products is covered on top with a very thin, elastic, but at the same time quite durable film of aluminum oxide.

After removing it mechanically, the newly cleaned surface from contact with air is instantly covered with an oxide film. Despite this, soldering aluminum at home is possible. If soldering is performed using tin-lead solders, you can use the following method.

Liquid mineral oil is applied to the place of the upcoming soldering, and already under the oil layer the surface is cleaned with a knife blade or scraper to remove the oxide film. After this, you need to apply solder with a very heated soldering iron. Usually a 50 W soldering iron is sufficient for this. For aluminum products with a thickness of more than 1 mm, it is better to use a tool of greater power.

Instead of mineral oil, you can use sewing machine oil or Vaseline oil, but gun oil is best suited for this purpose. The solder used must contain at least 50% tin. A good result is achieved by using low-melting solder POS-61. If you are soldering aluminum with a thickness of 2 mm or more, the surface must be thoroughly heated with a soldering iron before applying oil to the soldering area.

You can also apply rosin mixed with fine iron filings to the seam. A tinned file is used to wipe the seam area with added solder. Sawdust plays the role of an abrasive material, removing the oxide film from the surface of the product with sharp edges. As a result, tin adheres firmly to the surface, and aluminum is soldered more reliably.

In order for the work to be especially effective, the soldering iron should be slightly modernized. To do this, the working part of the copper rod is blunted so that a platform 4-5 mm wide is formed on it, after which a small longitudinal cut (7-8 mm) must be made with a hacksaw.

From a hacksaw blade, previously calcined over a fire, you need to cut out a small piece (1-2 mm), treat it to remove scale with a 20% mixture of sulfuric or hydrochloric acid, place it in the cut and compress it tightly in a vice.

Such a tip will more effectively remove the oxide film from the surface, and the aluminum will be better seized by solder.

In industrial conditions, soldering of aluminum and its alloys is also performed with a conventional soldering iron using a flux consisting of a mixture of oleic acid and lithium iodide.

How to solder aluminum at home

• Chemical stripping methods
• Application of fluxes and solders

Aluminum and its alloys are only slightly inferior in strength to steel, but they are very easy to process, have a decent appearance and have excellent qualities such as thermal and electrical conductivity. However, along with these properties there is the difficulty of soldering them. The question of how to solder aluminum is asked not only by novice amateurs, but also by those who do not have difficulty soldering copper, brass and steel.

Soldering aluminum is a complex process, so you need to know all its technology.

Working with aluminum is not easy because of its ability to instantly oxidize in air, as a result of which the surface is covered with a thin film of Al2O3 oxide, which has increased resistance to aggressive environments. Therefore, special mercury fluxes or replacement tips for soldering irons are used, or, depending on the soldering method, the oxide is removed in various ways.

Before soldering aluminum, they resort to mechanical removal of the film, cleaning the work area with a file, but contact of aluminum with water or air leads to the original state - the appearance of the same film.

For soldering aluminum, you can use a special flux.

Experts advise cleaning the soldering area with a brick or sand, without removing the dust, but applying molten rosin directly to it, then rubbing it with a soldering iron, pressing firmly with the tip. This will help break down the thin film that formed before applying the rosin.

Also, the stripped aluminum is filled with rosin and sprinkled with filings from an iron nail obtained during the filing process. Next, you need to tin the surface with a soldering iron, carefully rubbing it with the tip. Iron chips will destroy the film, while rosin will prevent the formation of a new film.

Chemical stripping methods

It is important not to allow the aluminum being stripped to come into contact with air; for this purpose, the soldering area is filled with flux or rosin, while heating it. Often small elements, such as wires, are dropped directly into rosin or flux poured into a container.

In addition to the mechanical method of removing oxide, there are several so-called chemical methods.

Cleaning aluminum before soldering can be done using copper sulfate.

Cleaning with copper sulfate. The point where solder needs to be made is cleaned with a file and moistened with two or three drops of copper sulfate solution.

The aluminum base is connected to the negative pole of the battery or accumulator; a small piece of copper wire, stripped and connected to the positive pole, is lowered into the solution without touching the base.

After turning on the 4.5 volt battery, a copper coating forms on the aluminum after a short period of time. The desired part is then soldered to the dried copper.

Use of abrasive powder. A liquid paste is prepared by mixing powder and transformer oil, which is applied to the cleaned surface and then rubbed in with a soldering iron until a layer of tin appears.

Another method is transformer. The product is connected to its negative side, a copper wire containing several cores is connected to its positive side. After closing the circuit, microwelding of aluminum and copper will occur. To speed up the process, soldering acid is used.

  Do-it-yourself bumper repair soldering

Application of fluxes and solders

For soldering large parts, such as cooling radiators, soldering irons with high power (100-200 W) are used; soldering irons with a power of 60-100 W can handle small elements quite successfully. Of course, the solder area is not particularly strong, but this is not required.

At home, fluxes F-64, FTBf-A, and FIM are suitable for soldering aluminum. Of course, you can use aspirin, technical petroleum jelly, grease, solder fat, and stearin as a flux.

Using special active fluxes makes soldering easier; they cope well with the oxide film, provided that the heating temperature is 250-360°C.

The solder is distributed over the entire joint surface, resulting in a strong connection between the parts. Flux must be removed using solvents, alcohol or a special liquid. The convenience of using such fluxes is that they are also used for soldering nickel, copper and steel.

As a rule, alloys of 2 parts zinc and 8 parts tin, or 1 part copper and 99 parts tin, or 1 part bismuth and 30 parts tin are used for soldering aluminum. Conventional PIC solders. 40 and POS. 60 also copes with the task.

Small holes (no more than 7 mm in diameter) in aluminum cookware can be soldered without a soldering iron. The existing enamel around the hole should be beaten 5 mm by lightly tapping with a hammer.

Now you need to use a file or sandpaper to clean the metal until it shines, using rosin crumbs or soldering acid, put a piece of tin in the pan on the hole and heat it over an alcohol lamp, which provides spot heating without destroying the remaining enamel. The metal, melting, will completely close the hole.

So, if you have the desire, you can solder aluminum at home.

Kirill Nikolaevich Andreichenko

Before tinning a soldering iron, you should find out what this procedure is and why it needs to be carried out. The bottom line is that as a result of soldering, due to overheating, the soldering iron tip oxidizes and, accordingly, loses the ability to normally melt the solder.

Source: https://rem-serv.com/flyus-dlya-payki-alyuminiya-svoimi-rukami/