Silumin welding, professional and at home

Technique

In production, in private workshops and car repair shops, craftsmen often wonder how to weld silumin. Argon arc welding is used to connect parts made of this material. The technology is welding with a non-consumable electrode. To make a reliable connection, a special silumin wire is used, which acts as a filler material.

Before using welding equipment, the part should be prepared. It is necessary to remove the oxide film that forms on the surface of the material. To do this, use sandpaper, a brush or a sandblaster. For chemical processing, a solvent is used.

What equipment is needed?

Before starting welding work, you should prepare the equipment. To connect silumin blanks, it is important to choose a high-quality device. A welding transformer is not suitable for this. You need an inverter device and a gas cylinder. In addition to them, they use: tungsten electrodes, a special torch and an oscillator.

You can weld silumin parts semi-automatically. The wire is fed under the protection of inert gases. When using a semi-automatic machine, it is important to consider some features:

If the direct current has negative polarity on the electrode, it will not be possible to make a high-quality seam.
To prevent the connecting wire from getting tangled when feeding, use a tool equipped with 4 rollers.

Advantages and disadvantages

Silumin welding has certain advantages and disadvantages.

Strengths:

There is virtually no workpiece deformation due to the small processing area.
Argon protects the treated surface from oxygen.
High speed of work completion.
Using this technology, it is possible to connect structures that are not amenable to other welding methods.

Weak sides:

When working outside, strong winds will interfere with the work.
If a powerful current is used to create an arc, an additional cooling system is required.
The equipment used to connect silumin is very expensive.
To work with tools and create a high-quality seam, you need to have practical skills.

Types of glue for silumin

For gluing, it is better to use special polyurethane or resin adhesives. Each of them has certain features that need to be studied before using them.

Polyurethane adhesive for silumin

Types of compositions:

One-component. The basis of the composition is polyurethane polymer. No solvent is supplied with it. Such adhesives are suitable for use on exposed parts of products. In order for the glue to react with the material, the surfaces must be moistened with a small amount of water.
Two-component. A special hardener is added to the polyurethane base. Metal surfaces do not need to be wetted before applying the adhesive.

In the second option, you need to mix the two components and apply the mixture to the joint.

Resin glue for silumin

To make a strong connection that will be resistant to high temperatures, it is better to choose a two-component adhesive composition based on epoxy resin. They are suitable for joining metal, plastic, stone, porcelain, wood.

Kinds:

Cold hardening. For the adhesive mass to dry, a temperature of 15–350°X is required.
Hot solidification. Used by industrial enterprises. To harden, the adhesive mass must be heated to 1000 °C.

To start working with epoxy resin glue, you need to mix two components in certain proportions.

Silumin figurine (Photo: Instagram / galery.grange)

Requirements

You can weld a seam using welding equipment by observing certain requirements:

Do not touch the electrode to the surface being processed when igniting the arc.
Before supplying gas, the burner nozzle should be warmed up. After 15 seconds, you can open the gas valve.
After stopping the supply of electricity to the electrode, wait 10 seconds and only then turn off the gas valve.

If the work is carried out at home, you can use a consumable electrode rather than a tungsten electrode.

Gluing or welding silumin?

From time to time I encounter the destruction of silumin elements. Externally, parts made of silumin look like aluminum, but this is only at first glance. Although it is quite easy to distinguish when the product is damaged. With the naked eye you can see sintered grains of powder. But, as they say, hope dies last. In the phone book you look for the number of a familiar argon engineer. You bring the part and after the first “chvark” you can see the sour face of this argon worker. And now, after further damage to the silumin parts, I no longer want to attempt to contact argon specialists.

And so I decided to google on the Internet to see if this same silumin can really be welded. First, I look at Wikipedia to find out what this silumin consists of. Its similarity to aluminum is not accidental, since this is the main component of this alloy. The second main element is silicon, the share of which ranges from 4 to 22% depending on its brand. Silumin also contains a small amount of impurities: iron, copper, manganese, titanium and others. Based on the fact that the percentage of silicon is different, then most likely there is a chance of welding.

So, having immersed myself in heated discussions on Internet forums, I realized the following: welding (soldering) is only worth it if the part is of some value and if it is under the influence of certain loads. Otherwise, everyone advocates gluing silumin parts together.

OK. Still, I would like to briefly outline the basic requirements for welding. Source Websvarka.ru.

Use only argon.
Silumin can be different. We must always try. Frankly, Chinese products are not welded. They melt down stupidly. But, for example, automobile parts from well-known manufacturers can be welded without problems.
To weld silumin, it is recommended to use special solders such as Harris-52, HTS-2000, ER 4043. They are intended for welding aluminum.
Before welding, the parts must be preheated to a temperature of 220 degrees Celsius. For more efficient heat removal, it is recommended to use steel gaskets. As far as I understand, this is necessary to prevent silumin from melting.
Try to avoid rigid fastenings to avoid crack formation.
Try it on a test piece before welding.

Now as for gluing silumin. Before gluing it is necessary to carefully prepare the surface. Clean as much dirt and oil as possible. Think in advance about how to fix the products after applying the glue. The most common adhesive is epoxy. Also, many recommend all sorts of five-minute exercises. After the glue has hardened, you can reinforce the gluing areas. Fiber-filled putty is suitable for these purposes. Yes, if you are hoping to find a special glue for silumin, do not waste your time. But here you can follow the logic of welders who are looking for solders for aluminum. So here, there are special adhesives designed for gluing aluminum.

Two-component adhesives COSMOFEN DUO and AL-1. Used in construction for gluing aluminum elements of windows and doors.

Here is a brief analysis to help those who are looking for ways to weld and glue silumin. Here the approach must be creative, when the sum of attempts gives rise to victory.

Can this type of welding be done at home?

Sometimes it is necessary to weld silumin at home. Stages of implementation:

Prepare the room, workplace and equipment. When welding with argon, you need to take care of a good ventilation system. A metal table is suitable for carrying out work.
To connect silumin parts, you need to use consumable electrodes.
The workpieces are heated to a temperature of 300 degrees. The electrodes need to be heated to 150 degrees.

The seam can be made with fusible electrodes. It is important that they consist of a silumin rod, which is coated with an alkaline saline solution. When carrying out welding work, a large amount of slag will be released. It should be quickly removed from the surface of the workpiece.

Advantages and disadvantages of silumin argon arc welding

This technology has a number of advantages, including:

firstly, this method is practically the only way to connect silumin blanks,
secondly, with a short arc the welding process will not take much time,
argon has proven itself to be a reliable protective element, so if all welding rules are followed, you will ultimately get a strong connection,
Everyone can carry out the welding process at home; experience will play a big role here.

Despite the large number of advantages, this method also has some disadvantages:

It is not recommended to weld silumin with argon outdoors, because the wind will blow the shielding gas away from the welding zone, so it is better to carry out welding work indoors,
for welding with argon you need to acquire all the necessary equipment,
Difficulties may arise with setting the welding mode,
In the case of using a welding transformer with a high current, it is important to additionally cool the silumin parts.

To summarize, it is worth noting that welding silumin is a rather labor-intensive process that requires care and certain knowledge.
In order for the final result to be of high quality, it is better to entrust this matter to an experienced specialist. [Total: 2 Average: 4/5]

Welding stages

To make a high-quality silumin connection, welding must be performed with strict adherence to technology. Stages:

After the arc is ignited and the gas is turned on, the wire begins to flow into the working area. It melts and creates a high-quality connection of parts.
When feeding the wire, it is held at an angle in front of the torch nozzle.
The wire must be fed slowly. Otherwise, molten metal will splash around and the quality of the weld will deteriorate.

When using a filler rod, do not place it across or make large deviations to the sides.

How to brew silumin

So, for welding silumin, argon arc technology is required. The equipment includes an inverter, a gas cylinder, an oscillator and a special burner. A non-consumable tungsten electrode is installed in the burner. Silumin wire should act as an additive here.

Before starting the welding process, silumin blanks must be prepared. The basic rule is to remove the oxide film.

First, you need to clean the edges of the parts to be welded using sandpaper, a wire brush, a sandblaster or any other method.
Next, chemical treatment is carried out. This can be any solvent, gasoline or caustic soda solution. If the latter material is used, then after processing it is recommended to rinse the metal workpieces with water pressure.

Welding is done with reverse polarity and a short arc. This can only be explained by the fact that with a short arc the metal melts better. The filler wire is fed into the welding zone, where it is also melted and combined with the base metal, ultimately forming a single, homogeneous liquid substance. When it cools, it turns into a monolith.

It is impossible to quickly feed the additive into the weld pool. This will lead to metal spattering, which will reduce the quality of the weld. The wire must be fed in front of the burner and held at an angle. The movement and feed must be uniform exactly along the seam. Do not deflect the filler rod or move it across. An even and narrow seam is a high quality connection.

Everything else, in principle, is exactly the same as when welding aluminum. Namely:

When igniting the electrode, do not touch the metal workpieces being welded.
Gas supply must begin 15 seconds after ignition of the tungsten electrode. This will ensure heating of the space in the burner nozzle.
When finishing welding, do not stop the gas supply. Shutdown can be carried out after 10 seconds, when the power supply to the electrode is turned off. This will ensure uniform cooling of the metal in the gap between the workpieces.

At home, you can weld silumin with a consumable electrode. For example, consumables from the well-known Swedish company ESAB brand OK 96.50. But here too there is some specificity.

The blanks are prepared in the same way.
Pre-welded parts are heated to 250-300C.
The electrodes are also preheated to 150C.

Electrodes of this brand consist of a silumin rod and alkali-salt coating. When welding, a large amount of slag is released, which must be carefully removed. Still, argon welding is of higher quality.

Safety precautions

Before you start welding silumin parts, you need to take care of safety. For this you will need:

Protective equipment - gloves, mask, shoes, robe.
Welding equipment must be in good working order. If it breaks down, you need to replace the device or have it repaired.

The room used for welding must be well ventilated.

Silumin welding is a technological process similar to joining aluminum parts. In this case, you need to choose the right equipment and consumables.