How to weld a cast iron block - Metals and their processing

Weld cast iron engine block

For a home craftsman, welding work with steel does not pose any difficulties. But not every self-taught welder knows how to cook cast iron using electric welding.

Features of the material

Cast iron is an alloy of carbon and iron, where the carbon content is 2.14%. Which negatively affects the quality of the connection.

The process is labor intensive due to:

formation of cracks and pores;
during processing, the appearance of hardened structures and rapid dulling of the tool;
thin material crumbles from overheating.

According to its composition, cast iron is divided into gray and white:

White ones cannot be welded due to their fragility and hardness. Suitable for grinding;
Gray (high strength, malleable) are easy to machine and have limited weldability.

Technology of welding cast iron with electrodes

There are 2 methods of welding cast iron - hot and cold.

Hot also includes semi-hot.

When hot joining, the part is heated to a temperature of 600-700°C, welding is performed and the cast iron product is slowly cooled in the furnace. With a semi-hot connection, the temperature is maintained at 300-400°C.

Hot and semi-hot welding requires additional equipment. In domestic conditions, a cold connection is used.

Edge cutting

Welding cast iron with an electrode at home requires chamfering. There is no need to degrease or clean the parts.

Chamfering is performed:

file;
emery;
Bulgarian

Note: sharp edges are not allowed. The sharpness is removed with a suitable tool.

How to cold weld cast iron parts

When connecting, do not overheat the heat-affected area (no more than 80°C). Take frequent breaks between passes. Use multi-pass welding.

first perform surfacing along the edges of the chamfers;
then gradually filling the seam;
After each pass, hot forge the roller.

Make rollers 40 mm long, scattered to reduce heating of the part.

How to weld cast iron using electric welding at home. What you will need:

current source (inverter);
electrodes 3 mm;
seam cleaning brush;
hammer for forging and removing slag;
cutter or cutter for cutting chamfers;
shield and gloves.

The process itself:

first, cutting edges and blunting sharp corners;
then surfacing along the edges of the chamfers;
then gradually fill the seam.

Forge each roller hot. Don’t rush, give the part time to cool (heating of the heat-affected zone is no more than 80°C).

After filling the weld, turn the part over and cut the edges on the reverse side. Perform welding as described above. Observing the temperature regime and forging each roller. At the end of the process, grind the deposited surface if desired.

Cold welding is used to repair batteries, vices, engine cylinder blocks and other structures made of gray cast iron.

Brands of electrodes for welding cast iron

In this article, you can get acquainted with factory electrodes and homemade electrodes for connecting different types of cast iron.

The table below will help you set the current on the device for different diameters of electrode brands:

TsCh-4;
OZCh-2;
OZZHN-1;
MNC-2.

The current values are indicated for the lower position of the electrode. For a vertical position, the current is reduced by 15-20 A, except for TsCh-2.

In order to save money, home craftsmen have adapted to welding cast iron with a conventional electrode with copper wire. below:

Also, copper wire will help in welding cast iron with steel.

Some craftsmen ask how to cook cast iron with a semi-automatic machine? On metalworking forums, experienced welders advise using PUNCH 11 wire. The connection is made with 2-5 cm stitches with forging, without gas protection on straight polarity. Current 90-110 Amperes depending on the thickness of the metal.

How to cut cast iron

Types of cutting are divided into thermal and mechanical. List of tools and methods:

The grinder is a simple and affordable way. Minus: the cut occurs in a straight line.
Pipe cutters have proven themselves well when working with pipes.
Reciprocating saw.
Electrode.
Oxy-fuel cutting is a good option. Oxygen flux will improve the quality of cutting cast iron.
Mobile installations Thermal cutter 2M (weight up to 5 kg).
Oxygen-lance cutting and plasma.

As you can see, there is plenty to choose from! The grinder is widely used in everyday life.

(24,00

Source: https://varimtutru.com/zavarit-blok-dvigatelya-chugun/

Welding a cast iron engine block

For a welder, when repairing cast iron products, the main thing is to achieve the strongest possible seam, since it is the welded joint that is always the weakest point. When a cast iron engine block is welded, cracks, chips and other damage often occur. Basically, the thickness of such a block is from 4 to 8 mm, therefore, it is recommended to use electrodes with a diameter of 4 mm.

Electrodes for welding cast iron engine block

Cracks occur in the jackets of the cooling unit, since it can be subject to shock and is negatively affected by defrosting processes. Breaks may also occur in the block, which are caused by the destruction of the sleeve-piston group. At first you may get the impression that the damage can be repaired easily, but in reality this is not the case.

The properties of cast iron put forward additional requirements for welding technology. There is also a great responsibility here, since incorrect movements can ruin the entire block. All this can take more time due to the need to interrupt the seam, simultaneously covering the slag and other things.

All this is carried out in accordance with GOST 2246-70.

Welding a cast iron engine block at home

Weldability of cast iron and other properties

Welding a cast iron engine block using a semi-automatic machine requires compliance with all the processing features of this material. Cast iron is highly saturated with carbon. But when exposed to temperature, it begins to evaporate and reacts with surrounding elements, which forms CO. When this compound gets into the metal, it leads to the appearance of cracks during welding.

Welding a cast iron block

It is also worth noting the property of rapid cooling of the metal. If we allow a sharp drop in temperature, which in this case can happen in a completely natural way, then pores and cracks may form in the metal, not to mention other deformations. During cooling, compounds of different crystal lattice structures are formed in cast iron. Accordingly, all these connections can have different volumes. This can cause internal pores to form.

It is also worth noting the low plastic properties, which leads to the appearance of overstresses in the metal, which also causes cracks to appear. This is especially true when welding thin metal with an electrode. The metal is highly brittle, which creates additional difficulties in processing and creates conditions under which cracks can form even with relatively small mechanical impacts.

Causes of crack formation

Welding a cast iron engine block with argon often works by sealing cracks. But they can also appear during the welding process. The main reason is a sharp drop in temperature, or a sharp increase.

To avoid this, you should gradually heat up the cast iron before welding, and also do this after it, since otherwise it will cool down too quickly. Cracks may appear due to the active release of carbon from the composition when heated.

To prevent this process, they use flux, which replaces the lost carbon, and also use protective gases, which will prevent the carbon from combining with oxygen.

Crack formation on a cast iron engine block

Voltage may also be generated due to hydrogen that has entered the seam from the atmosphere, or can get there in the electrode winding. Here you need to more carefully select the coating and protective environment to ensure reliable insulation for the metal.

Insufficient carbon replenishment, which occurs with incorrectly selected flux, can also cause cracks. In this case, deformation occurs due to the unevenness of the internal structure of elements in which there is no carbon.

They create deformation that leads to surface rupture or the creation of internal pores and cavities.

Modes and characteristics

There are different types and methods of metal welding. In order for the seam to be as reliable as possible, when creating it you need to be guided by proven parameters that can guarantee the successful completion of the work.

Workpiece thickness, mm	Electrode diameter, mm	Current strength, A
1	1	30-40
2	1	60-80
3	2	90-120
4	3	120-160
5	4	150-200

Welding technology

When welding a cast iron engine block at home or in production, all specified points of the technology should be carefully followed.

The surface is cleaned to a shine. This can be done using a metal brush.
It is necessary to degrease the surface with solvents to remove oxidizing film and other chemical deposits.
You should select the required flux and place it along the welding edge, at least throughout the first stage of the seam.
Next, you need to heat the metal with a gas torch to the required temperature for several minutes, since welding on the fly is not recommended.
When the metal reaches the desired temperature, you can begin to weld the metal. This should happen in small sections, approximately 10-15 cm at a time.
When the seam is completed, you need to heat the metal for a few more minutes, gradually lowering the temperature to avoid rapid cooling and sudden changes.
Check the quality of the resulting connections. In the home sphere this is done visually, but in production there are various professional methods of internal in-depth control.

"Important!

After each time, you need to beat off the slag, and do not forget about warming up, so that there is no sharp drop in temperature.”

Source: https://svarkaipayka.ru/tehnologia/svarka-metalla/svarka-chugunnogo-bloka-dvigatelya.html

Is it possible to weld a cast iron engine block?

» Miscellaneous » Is it possible to weld a cast iron engine block

23.10.2018

Massive cylinder housings are made from cast iron. This durable material has one significant drawback - it is very fragile. When struck, cracks form on it or the wall is completely destroyed. Due to small defects, service stations often suggest replacing the engine, although cracks can be effectively eliminated by welding ICE (internal combustion engine) blocks.

Is it possible to repair a cast-iron engine block yourself, and how to do it correctly, professionals tell you. They have proven in practice that in a garage, having a welding machine and working skills, it is possible to restore the tightness of the metal and its operating parameters. This engine has been in use for many years.

The material from which the engine block is made

Two materials are used to cast engine cylinder blocks. Aluminum flares are considered disposable and low economical. Special alloy alloys are much more expensive than traditional cast iron with nickel and chromium additives.

Cast iron tolerates overheating well, has the necessary rigidity, and has a large margin of safety. Two types of cast iron are used: gray is easy to weld, white is high-carbon, forms a loose seam, and requires special welding skills.

Methods for welding a cast iron cylinder block

To reliably eliminate small defects in the form of cracks, there are several effective methods. Difficulties arise when repairing aluminum alloys. This is due to a change in the properties of the metal when heated, the formation of a refractory oxide film. The aluminum engine block requires some gas welding skills. If cracks appear in cast iron, welding of the cast iron block is carried out in three ways:

when heating everything;
fragmentary heating of the repaired area, used when it is impossible to completely heat the overall body;
electric welding on a cold surface, this method is most popular due to the ease of execution and the quality of sealing cracks.

Hot welding

According to the technology, the part to be welded must be heated to +600-700°C, this is done in special furnaces and furnaces. Craftsmen carry out the process in casings with an asbestos layer. Gas burners are used for this. When heated, the metal retains its plasticity and viscosity. It is better welded by the electric arc liquid bath method using electrodes of the MNCh-2, OMCh-1, OMCh-2, OZCh-2, OZZHN-1, TsCh-4 brands.

Source: https://piter-at.ru/raznoe/mozhno-li-zavarit-chugunnyj-blok-dvigatelya.html

How to weld a cast iron engine block | mk-soyuz.rf

How to cook cast iron using different types of welding

Cast iron is an alloy of iron and carbon, with a carbon content of more than 2%. Due to its low melting point compared to steel (1200 - 1250 °C), it quickly passes from the molten state to the solid state. In this case, pores form in the weld due to the intense release of gases from the weld pool, which continues during the crystallization stage.

To correctly determine how to cook cast iron, you must consider the following features:

accelerated cooling leads to the formation of a bleached layer (cementite) in the area near the seam and creates difficulties for its further mechanical processing;
its high level with uneven heating or cooling causes cracks to appear during welding;
the high fluidity of cast iron in a liquid state necessitates the use of preforming;
strong formation of gases in the liquid bath causes porosity of welds.

How to brew cast iron

The connection of cast iron parts is carried out by gas, thermite, foundry, electroslag, arc welding, as well as soldering. Welding work is performed without heating (cold metal welding), with local or general heating of the product.

Cold welding method

This type of cast iron welding is used more often. Preparation of defective areas involves cleaning, milling, drilling and other plumbing work until a clean metal surface is obtained. Defects located further than 20 mm from each other are drilled out or cut out separately; if they are located closer, the defective area is cut out completely. Installing pins to strengthen the seam

In practice, several options for cold welding are used: copper-iron, copper-nickel, nickel, iron-nickel, steel and other electrodes.

By using copper-nickel and copper-steel electrodes, it is possible to obtain a deposited metal that is easy to process. Surfacing is formed by single-layer or multi-layer laying of beads.

Welding with steel electrodes is performed as follows. In order to form a durable layer of deposited metal, pins are inserted into the cast iron product, which are then scalded. This method is used when repairing bulky and heavy cast iron parts. With this method, the weld metal contains an increased amount of carbon, which increases its hardness and promotes the formation of cold and crystallization cracks. To reduce this hardness, two methods are used:

1. The carbon content is reduced by reducing the depth of penetration of the base metal, or the process of joining the metal is carried out over a layer of oxidizing flux containing up to 30% scale, which acts as a carbon oxidizer.

2. The structure of the weld metal and its chemical composition are obtained, close to the structure of gray cast iron, which is achieved by applying a thick layer of graphitizing coating to the steel rod, which contains 30% graphite and 30% ferrosilicon. Steel electrodes are widely used in the repair of small non-critical cast iron products that do not require any processing after welding. Cold welding zone

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Copper-iron electrodes are used for welding individual defects or small discontinuities that cause leaks on critical castings operating under pressure. The deposited metal from these electrodes is perfectly processed. The welded joint is a mechanical mixture of an iron-carbon alloy and copper, connected to the base metal by common steel crystals, as well as by partial penetration of copper into the micropores of cast iron.

Copper-nickel electrodes are used mainly for welding casting defects on working surfaces on which a local increase in hardness is unacceptable.

Iron-nickel electrodes are used for welding individual small defects on critical surfaces of castings made of gray or high-strength cast iron.

Nickel electrodes of the brand are used when correcting small defects in critical products. Multilayer structure during welding work

Arc welding using electrodes made of austenitic cast iron, coated with a current-carrying layer and intended for welding casting defects and repair welding. Welding work is carried out with direct current of straight polarity. The conductive layer of electrodes has good electrical conductivity, so the arc burns alternately between the metal rod and the product, as well as between the product and the coating.

Gas welding of cast iron is rarely used and is limited to repair work (welding casting shells, surfacing worn surfaces, eliminating external defects). The best results are obtained by welding using an oxygen-acetylene mixture, so other flammable mixtures are practically not used for welding cast iron. Welding is performed with preheating, general and local.

For general heating, muffle furnaces, induction heaters, and furnaces are used that can heat small parts up to 300–400°C, and large parts up to 600–700°C. For local heating, gas burners or blowtorches are used. Due to the high fluidity of cast iron, welding is performed exclusively for the lower positions of the seam. The weld pool is protected by manually applied fluxes.

Mechanized welding methods and how to weld cast iron

Electric welding of cast iron (electroslag welding) provides satisfactory seam properties of the welded joint. In this method, cast iron plates are used as electrodes.

With the correct selection of electrodes and the use of fluoride non-oxidizing and desulfurizing fluxes, as well as slow cooling of the weld and heat-affected zone, characteristic only for electroslag welding, it is possible to obtain welds without cracks, bleached areas, pores and other defects that determine the quality of the welded joint.

Is it possible to weld cast iron in a protective gas environment?

The carbon dioxide arc welding method is very widely used, as it allows for a small penetration of the base metal. The performance of welded joints and the composition of the weld metal depend on the welding technique and mode, the size of the products, and the composition of the electrode wire. Using various welding modes and techniques, it is possible to obtain deposited metal with the required structure.

The best results are obtained when using 09G2SA wire with a diameter of 1 mm with a current value of no more than 100 - 120 A, an arc voltage of 18 - 21 V, and a welding speed of up to 12 m/h.

Using this method, you can join plumbing pipes made of gray cast iron, repair automobile and tractor parts that do not require further machining, and weld high-strength cast iron and steel.

Is it possible to cook cast iron with a semi-automatic machine?

In auto workshops, a client can weld a cast iron block using a semi-automatic machine without any problems. Welding cast iron semi-automatically at home is performed using flux-cored wire and gives fairly good results.

Source: https://elsvarkin.ru/materialy/kak-pravilno-varit-chugun/

How to weld a cast iron engine block using electric welding

Cast iron is used everywhere in everyday life, from batteries and other plumbing elements to fence structures, car parts and machine tools. The difficulties begin when it comes to welding this metal. Welding cast iron with an electrode at home is not an easy job.

If you can work with ordinary steels without particularly careful preparation, then simply welding a seam onto a cast iron part, without preliminary preparation, is very difficult. Failure to comply with basic technologies can lead to overheating of the metal, which means increased fragility and other problems.

Let's look at how to brew cast iron at home using an inverter.

Features of welding cast iron, types of cast iron

Experienced welders can determine the weldability of cast iron from just a
cut. It is believed that if the structure of the metal is finely dispersed and close to gray in color, then such cast iron can be welded much easier than coarse-grained metal of dark shades.

If we are talking about welding parts that were in an oil environment or were subject to regular oxidation in an aqueous environment, soil or other similar conditions, then such a welding material will not be suitable.

Since cast iron is a metal with limited weldability, it is worth taking into account the following features:

The metal is fluid, so the main and only correct welding position is the bottom one.
If you do not observe temperature conditions and chop the metal, then when the carbon burns out, pores will form.
Low ductility and non-compliance with temperature conditions are the main causes of stress at welded joints.
Molten iron can create oxides that will have a higher melting point than the parent metal.

The problem you may encounter is the formation of cracks at the welding points when the part cools.

This can only be solved if we fully adhere to the technology, in our case - cold welding.

Cast iron welding methods

There are three ways to weld cast iron:

Hot welding. The main and most correct method. It consists in the fact that before working with the electrode, the workpiece is heated to 600 - 650 degrees. This allows you to avoid the formation of compounds with a high melting point, overheating and tension of the metal at the joint. Heating is carried out in ovens, gas or other burners. For home conditions, this method is a stretch, because in addition to the heating device, you need to know at what moments you can work at the welded joint, how to cool the metal and many other nuances.
Semi-hot welding. It is practically no different from the previous method, with the exception of the heating temperature. Here the product is heated to 300 - 350 degrees.
Cold welding. The method does not involve heating the workpiece, but it is based on many other technological aspects, failure to comply with which will lead to the impossibility of making a high-quality seam. Welding cast iron at home with an electrode is carried out in this way.

Preparing cast iron for cold welding with an inverter

Before welding cast iron, it must be prepared. First, the desired area is cleaned with a grinder with a flap wheel or other suitable attachment. After stripping the top layer to non-oxidized metal, it is necessary to carry out mandatory degreasing with gasoline or any other solvent. If you decide to repair the crack, then you need to clear the metal until it ends, and drill a hole with a diameter of 10 mm in this place.

It is worth talking separately about the following preparation features:

1. Hairpins. Arc welding of cast iron can be carried out either layer by layer without the use of supporting elements, or using
studs. The studs are made of steel. Their dimensions are strictly regulated, for example, the diameter should not exceed 40% of the thickness of the cast iron. The protrusion of the stud above the metal is limited to 4-6 mm, and the distance between the studs should not be more than 6 diameters. The amount depends only on the size of the connection, but not more than 25% of the fracture area

2. Cutting edges.

Note! The edges should not have a sharp cut at the junction of two parts of metal; the optimal shape is spherical.

3. Electrodes must be special. It is almost impossible to weld such metal with conventional electrodes on steel, so it is worth purchasing an electrode with the addition of copper, chromium, nickel and other alloys that facilitate welding onto fastidious cast iron.

Welding process

In the previous paragraph, we discussed the preliminary preparation, and before starting welding, we need to consider the main technological points:

Connection polarity is reverse;
The power of the welding machine is minimal for a given electrode thickness;
The length of one continuous weld should not exceed 30 - 50 mm;
It is necessary to prevent overheating of the metal due to frequent breaks;
The first and last layers of multilayers are hammered with minimal force.

Source: https://crast.ru/instrumenty/kak-zavarit-chugunnyj-blok-dvigatelja

Welding a cast iron cylinder block – Osvarke.Net

The need to weld the cylinder block arises when cracks appear on it. A large number of blocks are made by casting cast iron. Cast iron is a fairly strong and hard material, lends itself well to casting and has a low melting point compared to steel. The negative side of the material is fragility and low viscosity. In this regard, the most common malfunction of blocks is the appearance of cracks.

Rice. 1. Cylinder block

Preparing the cylinder block for welding

Before carrying out welding work to repair the unit, it is necessary to thoroughly clean it of dirt, oil and other contaminants. Cracks and discontinuities identified on the block must be marked with chalk or other convenient means.

In order to avoid the growth of cracks, its edges must be drilled. Small cracks up to 5 mm can be welded without cutting the edges. Deeper cracks must be made with cutting edges.

Rice. 2. Drilling cracks

The hole must not be made through, but only until a gap appears along the entire length of the crack. The crack prepared for welding should resemble a joint with a V-shaped bevel of the edges. This is done so that during welding all gases and impurities contained in the welding materials and base metal can escape to the surface of the weld.

Cylinder block welding methods

Cylinder blocks made of cast iron must be welded in accordance with cast iron welding technology. The cylinder block can be welded in the following ways:

welding with preheating of the entire cylinder block;
welding with preliminary local heating in the welding zone;
cold welding without preheating.

Welding of a car block must be carried out strictly in compliance with all technology standards. Work of this kind must be entrusted to an experienced and qualified welder. If the repair was carried out incorrectly, the unit may completely lose its functionality, causing even greater damage and breaking off its parts.

Hot welding of a cylinder block is performed with pre-heating of the block to a temperature of 600-700 °C. Heating is carried out in furnaces, furnaces or heating pits. For heating, special casings made of steel with a thin layer of asbestos are also used, in which the welding site is left open, and heating is carried out with gas burners. Preheating allows you to preserve the mechanical properties of the base metal.

Welding is performed with coated electrodes of the OMCh-1 brand or others for welding cast iron using the appropriate method. When arc welding, they try to keep the liquid metal in the weld pool until the edges are completely filled. After welding, the block must be cooled for a long time.

Welding with preheating at the welding site is used for volumetric structures, the heating of which is impossible completely due to their overall dimensions.

Cold welding without preheating the block

There are many methods for welding cast iron products without preheating:

manual arc welding (a large number of welding electrodes have been developed);
semi-automatic welding in carbon dioxide and flux-cored wire;
argon arc welding;
welding with carbon or graphite electrode submerged arc (cast iron rods are used).

for welding cast iron cylinder blocks using the argon arc method

In the next video, the author welds a crack on a block using the argon arc method with a non-consumable electrode.

Save:

Source: http://osvarke.net/svarka-avtomobilej/svarka-bloka-cilindrov-iz-chuguna/

How to seal a cast iron engine block?

» Other »

Question for experts: There is a crack in the cylinder block, the block is cast iron, how can it be repaired?

Best regards, KoSten!!!

Best answers

Experts here will advise. First, you need to stop the crack. To do this, you need to drill out the edges of the cracks. Secondly, clean with sandpaper and degrease with solvent. And only then can it be sealed with an ecoxide composition.

(reinforced with fiberglass)

Can be pinned. But first you need to examine it.

depending on where. there are options.

Brew electrodes over cast iron. You can also seal it with epoxy using fiberglass.

If you brew with argon it is not possible. then cold welding on cast iron.

Epoxy will not withstand the temperature

block replacement. thermal expansion cannot be defeated. You'll just be wasting your time and energy

If the channel is oily or antifreeze, then it is useless. Expansion when heated is fraught with consequences. Actually, epoxy resin and mesh (fabric) in three layers.

cold welding CHECKED

Argon is possible, but it won’t take long to change the beam, it costs a penny at a showdown

On ships, cracked engine blocks and cylinders were glued with epoxy resin.

I once heard that someone glued aluminum blocks using a special technology. Cast iron must be cooked, cast iron is cooked.

I agree with “satalgat”. We used to glue it with three or four layers of gauze and epoxy, there was no fiberglass and the patch held up perfectly. There is another option - put jumpers across the crack on the screws and tin (solder) on top.

And it is also necessary to reinforce it with fine brass or copper mesh. Or just solder it with a mesh, although this is an option for a year or two, if everything goes well. Oil and antifreeze channels are also repaired. In all cases, drill the ends of the crack. True, all this is done on a removed empty block.

If you are interested, write, I’ll tell you and draw what I know.

And if you just get there, then the best option is cold welding

Brew it, just find a good welder and he will weld it for you with ease and you can continue driving

answer

This video will help you figure it out

Answers from experts

Will you cook/glue it yourself?

good to troll. you can be seen a mile away you troll

Here, as in the proverb * Died, so died *

don’t forget to boil the inside of the cylinder

Well, brother, it’s clear that we can’t help you.

Depending on where it cracked, if it’s on top then just enough epoxy to seal it

It depends where it burst. Cast iron is cooked with a copper electrode; the cast iron part must be heated to 600 degrees, then slowly cooled. In short, you need an experienced welder.

For replacement. Too important detail

It depends on what kind of crack... on Zile 130 the epoxy with filler lasted 4 months, you can try to get the agronomist to help you

Bandage + epoxy glue + metal plate + screws. This was the case in the 80-90s. Today, cold welding is done “on the knee”. Or just brew it.

Try welding, if it’s cast iron, then using a cast iron electrode, if it’s duralumin, then welding in an argon environment!

process by cold welding

try cold welding

There are electrodes for cast iron, but cracks can also occur inward ((

We must look from the inside. Things could be much worse there.

And cast iron can be welded perfectly by electric welding. Electrodes “on cast iron”. The current is constant. The polarity is reversed, you must first preheat the welding site and, of course, prepare it (remove the chamfer, etc.).

Cast iron cannot be cooked (in the full sense of the word) under any circumstances. No one, no matter how convincingly, could prove the opposite. This is an immutable fact based on the origin of cast iron as a solid solution of carbon in iron. There are several ways out of the situation. 1. Seal the cracks with “goujons”, i.e. drill the crack with a chain of holes (say 5 mm in diameter) with a distance between the centers of the holes (for this case) 8 mm.

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Cut M6 threads in the holes and screw in pieces of rod with M6 threads using epoxy glue. After the glue has cured, clean the protruding ends of the threaded screws flush with the main surface. After this, 5 mm holes are drilled again in the spaces between the screws so that the thread in the new hole passes through both adjacent plugs. Well, cut the thread again and screw in the screws.

The only requirement is excellent degreasing of everything that will come into contact with the glue. The method is more than a hundred years old, but earlier Bakelite was used instead of epoxy. Even cracks in load-bearing parts are repaired intelligently. 2. Seal the cracks by soldering with brass, or better yet, silver solder. But at the same time, the block must be heated very much, which can lead to its leash, and not every welder can be trusted to perform this procedure. 3.

It is quite easy to heal cracks on non-strength surfaces as follows. An overlay is minted from sheet iron to cover the crack and repeat the shape of the surface of the block. Next, the block is sanded or sandblasted in the crack area, and LOCKTITE ULTRA BLACK or similar sealant is applied to it. JUST DO NOT USE CHEAP RED SILICONE SEALANTS. The sealant layer is 1-2 mm depending on the accuracy of the lining profile.

The sealant is allowed to collect moisture from the air for about 10 minutes, then a patch is applied and secured with blind rivets or screws. Of course, holes for screws must be made before applying sealant. So, it’s too early to throw away the block. Guys! Blocks and other load-bearing parts made of cast iron cannot be cooked. Yes, there is the Paton Institute in Kyiv and the first welded, not riveted bridge (there is a PATON bridge in Kyiv) was created by Paton.

And in St. Petersburg there is an Institute of Welding Equipment, and in Minsk. But the fact that in these organizations there are guys (even truly talented ones) who are trying to cook cast iron does not indicate that this problem has been solved. Alas! Alas!. And a debate on this topic is tantamount to a debate about whether it is possible to jump from the 10th floor without a parachute. Can!!! Of course you can, but the result is predetermined. Cast iron is, I repeat, a solid supersaturated solution of carbon in iron.

The solution is oversaturated and therefore, when the casting hardens, carbon precipitates in the form of inclusions that are either spherical, worm-shaped, or flake-shaped and plate-shaped. The shape of graphite inclusions depends on the alloying of cast iron and the heat treatment of the casting. The presence of graphite inclusions determines the most important characteristics of cast iron: - excellent anti-friction properties - insensitivity to defects such as cracks, holes, etc.

-poor susceptibility to tensile stresses (loads) -impossibility of welding.

Welding cast iron is impossible because during welding the welding zone is remelted and the precipitated carbon dissolves again in the iron, and since during welding the cooling rate of the weld is very high (and it can be reduced by cooling the block from 1000-1200 degrees, together with the furnace for 30- 40 hours), then the carbon does not fall out entirely in its previous form, but forms other compounds of carbon with iron, and these particles have a larger volume than the main structures of cast iron.

As a result, the seam is overstressed and will definitely develop near-weld cracks, if not immediately, then in the near future. Due to the fact that cast iron is insensitive to cracks, the part will remain functional, but the seam will always sweat oil and the cracks will grow. And time will do its job. Propaganda for welding cast iron does not contain responsibility for the recommendation (and cannot, of course, contain it), but how many people fell for this, firmly believing that they had caught an incompetent welder.

But the welder was not incompetent, but simply incompetent.

popados!!!! go to the auto store to get a new unit.

I agree it has taken root on the Volga

there is no way to change welding - it is unreliable
and can fail at any moment

Crack in the cylinder block.
What can be done to fix it? Question: Crack in the cylinder block. What can be done to fix it?

The repair procedure is as follows: After warming up the engine, you will have to “turn it off” and use the additional “pump” drive to make the “cooling system work”,

apply the preparation HG9043 Hi-Gear METALLIC-CERAMIC RADIATOR & BLOCK SEAL (METAL CERAMIC SEALANT Hi-Gear).

Hi-Gear metal-ceramic sealant is designed for repairing cracked cylinder heads and blocks, head gaskets, radiators (for commercial vehicles). Guaranteed to eliminate antifreeze leaks through the head gasket. Repairs cracked aluminum or cast iron engine heads and blocks with weld strength.

Withstands vibration, temperature changes, high pressure, does not wash out, does not dissolve. This formula contains a unique combination of the finest ceramic fibers, giving the repaired area additional strength characteristics and the ability to repair larger damage. The packaging is designed for a cooling system with a volume of 10 to 22 liters.

After eliminating the crack, you will have to change the oil.

Metal-ceramic sealant for repairing leaks

I checked it myself in practice.
In our experience, we launched two units with this drug, 4 cylinder heads and about 10 metal radiators, we tried plastic ones - they play too much. At least this is a chance, it's inexpensive to try.

I have 4 cases of block treatment with a positive effect. The first of them, in 1975, a ZIL-157 block with two cracks on top on both sides, 30-35 cm long, was defrosted. It was sealed with epoxy and aluminum. powder. It was a combat vehicle and took part in exercises.

The second GAZ-66 and ZIL-131 in 1978, the situation is approximately the same, repaired with epoxy. The last case was in 1999 ZIL-130, a crack in the middle of the block along the entire length of the engine.

The crack was repaired using modern means (I don’t remember what it was called, I think it was cold welding), a 6 mm steel plate was placed on top of the thread. And all this continued to drive.

We tried to cook, no options!!!! It's better not to try, it will only get worse.

Personal practice. It was winter, after a shift on the ZIL 130 I opened the taps and went home for the weekend. On Monday morning, while filling up with water, it turned out that a piece of rust or scale had blocked the outlet of the cylinder block.

The water did not glass completely and as a result squeezed out the wall of the block by about 10 - 11 cm. We mixed epoxy with aluminum powder, poured it around the perimeter and put a plate on top and secured it with 12 5 mm bolts. Then I worked on this machine for another 2 years.

But in winter I always waited until all the water drained.

Brew it, just find a good welder and he will weld it for you with ease and you can continue driving

Source: https://dom-voprosov.ru/prochee/chem-zakleit-blok-dvigatelya-chugunnyj

Soldering cast iron: methods and methods, selection of flux and solder

Graphite, as one of the main components of cast iron, has a strong influence on the course of processes. During thermal, mechanical and other types of processing, its influence is felt on the quality of the seam and its durability.

When soldering and tinning, this structural element leads to incomplete wetting of the base with molten solder and tinning composition.

Such simple technological steps as sandblasting the surface or burning an oxygen gas burner in an oxidizing torch do not always bring the expected effect and result that satisfies the initial requirements.

On an industrial scale, the method of electrochemical action of a salt solution heated to 512 ° C to remove surface active carbon (graphite) is gaining increasing momentum.

Low temperature soldering

Soldering at low temperatures requires a special approach and additional pre-treatment. Pre-soldered surfaces must be treated with PV209 flux or its close replacement PV284CHH. Processing temperature 620-695oC.

Electrochemical treatment with a saline solution followed by degreasing the surfaces with acetone, alcohol or another substance suitable for these purposes brings good results.

The choice of using a soldering iron or a gas torch remains with the performer and does not affect the result obtained.

The soldering process is carried out with a soldering iron or torch. The most satisfactory result can be obtained by using fluxes based on zinc and chlorine, which also include chloride salts of some metals. Low-melting solders for soldering cast iron may require preliminary copper plating of the surface. It can be produced by electroplating. At home, contact plating with copper sulfate is available. The optimal solder is lead-tin solder or tin soldering.

High temperature brazing of cast iron

For this type of connection of cast iron elements, copper-based solders are used. Although soldering with brass (an alloy of copper and tin) is not the best solder due to its melting point. If the budget and the estimated cost of the resulting product allows, you should think about solders, where silver is the base and contains nickel impurities.

Such an alloy has intermediate melting rates between different types of solders and forms a strong and high-quality connection even in the absence of much prior experience in this field. This method of soldering cast iron parts requires the use of active surface fluxes that can dissolve and coat the protruding graphite phases on the surface with a film.

Wetting of metal and solder becomes maximum and does not cause trouble, flowing down and “escaping” from the seam being soldered. The main advantage of using solders with silver and nickel is the absence of the need for mechanical and high-temperature pre-treatment.

The lower temperature of the process does not allow phase transformations to occur in the cast iron, making it practically impossible for brittle cementite to form in the cooling part.

Copper solders, due to their high melting point, are best avoided when soldering critical parts and assemblies, due to the likely overheating of cast iron. phosphorus in the solder, with increasing temperature and when interacting with metal, can lead to the formation of phosphorus-iron eutectics, characterized by fragility and low mechanical characteristics.

Preliminary preparation of surfaces and cutting of cracks before soldering cast iron

Particular attention should be paid to the pre-treatment of the surface that is planned to be soldered or tinned.

As a rule, this repair method is applicable to cracks and chips in massive parts, when replacement with a new element is technologically unjustified or due to cost considerations or manufacturing difficulties.

The cutting of cracks and their processing must be maintained within the framework of certain rules, which will allow to prolong the operation of the entire assembly and obtain high-quality contact between the metal and the solder.

Preliminary tinning of the surface improves the quality and reliability of subsequent soldering. Tinning occurs in the following order:

The parts are pre-cleaned using mechanical methods until a uniform shine appears on the surface. Soldering cast iron at home involves the use of a metal brush and sanding pads of appropriate grain size.
Perform degreasing using liquids intended for these purposes.
Pre-flux treatment is carried out. An aqueous solution of zinc chloride, with the addition of chloride salts, can be considered a universal remedy for cast iron products, regardless of the shape of the graphite inclusions.
The elements are heated to flux operating temperature. Flux is applied.
The area to be soldered is further heated to the melting temperature of the solder.
Solder is applied. An element with a film of tinned metal is ready for further soldering.

The processing of cracks, which are relatively small in size compared to the geometric parameters of the entire part, is often difficult precisely because of this fact. It is extremely difficult to tinning in the depths of a crack due to the impossibility of getting there. If a layer of solder simply preserves such a crack without penetrating deeply, there is still the possibility of internal exposure to moisture on the metal, which ended up there during soldering or fell out in the form of dew due to temperature changes in the resulting cavity.

Based on the indicated problematic aspects of crack soldering, it can be argued that preheating and additional heating of the area bordering the crack will allow the solder to remain in the molten state for a longer time and penetrate as deeply as possible into the crack cavity.

If there is such a possibility, there is a need for further use of the workpiece in difficult conditions, it is necessary to perform a twenty-minute annealing at a temperature of 700-750 degrees Celsius. This allows the solder to diffuse into the base metal, thereby strengthening the seam and giving it high physical properties.

Each method of connecting cast iron elements has its own advantages and disadvantages. Soldering and tinning are no exception. These methods must be selected in accordance with the objectives and the degree of strength characteristics guaranteed by these methods. The use of soldering and tinning of cast iron in furnaces using brass solders is not justified due to the temperature transformations of this alloy at temperatures below the melting point of copper and tin burnout.

Source: http://solidiron.ru/obrabotka-metalla/pajjka-chuguna-metody-i-sposoby-podbor-flyusa-i-pripoya-podgotovka-detalejj.html

How to weld a cast iron engine block using electric welding - Metalworker's Guide

Serious damage to the cylinder block or its head is not a death sentence for the engine. Yes, on the one hand, it is easier to change the damaged element. Now it’s not a problem to buy, for example, a new short block (cylinder block assembly). But in some cases, the price of such a purchase may be equal to half the current cost of the car itself. Therefore, repairing engine components using welding may be a more profitable option.

The result of pistons meeting valves on a Ferrari engine. It was vital for the owner to save the cylinder block and head. No sooner said than done. The head was saved with the help of a complex of welding works. The result of the meeting of pistons with valves on a Ferrari engine. It was vital for the owner to save the cylinder block and head. No sooner said than done. The head was saved using a complex of welding works.

Theory and practice

With the help of welding, it is possible to successfully treat cracks, restore the walls between the cylinders, and even seal a hole in the block punched by a connecting rod. In each specific case, only the master himself determines the feasibility of such complex repairs and its cost. The limitation is the location and nature of the damage. In some cases, successful repair is impossible in principle, and in others the cost of the issue is very high.

The specifics of welding depend on the material used to make the parts. It is easiest to work with aluminum alloys - their melting point is low, and the metal flows well. Things are much more complicated with cast iron. To work with it you need higher temperatures and more expensive equipment.

For high-quality welding, it is necessary to heat the parts to high temperatures. This reduces the effect of strong local heating and improves the quality of work. For high-quality welding, it is necessary to heat the parts to high temperatures. This reduces the effect of strong local heating and improves the quality of work.

Any welding work involves strong local heating of the part, as a result of which it can “lead” (violation of its geometric dimensions). Therefore, it is very dangerous to carry out such activities on a motor installed on a car, and without final quality checks.

The banal welding of some torn bracket with this approach can lead to the fact that the nearest cylinder will move, and the piston in it will generally jam. Professionals very often encounter negative consequences of such welding to varying degrees of severity.

Repeated repairs are much more difficult for the master himself and more expensive for the client.

High-quality welding technology involves preheating both aluminum and cast iron parts. Elements made of light alloys are heated to approximately 250ºC, and elements of heavy metal - up to 350–400ºC. More is possible if the equipment and the welder’s patience allow working with a hot part. In this case, the consequences of strong local heating are minimized. After welding, the parts are slowly cooled.

The damaged surface of the block head is mined down to pure metal and after heating it, the metal is welded. Due to the severity of the damage, the operation is carried out in several stages. Next, the head is sent to the milling machine for processing. The damaged surface of the block head is mined down to pure metal and after heating it, the metal is welded. Due to the severity of the damage, the operation is carried out in several stages. Next, the head is sent to the milling machine for processing.

THIS IS INTERESTING: How much copper is in brass

After any type of welding, it is necessary to check the geometry of the parts, for example, the diameters of the cylinder along the entire height and the plane of the mating surfaces of the block or its head, as well as their crimping in a hot water bath. If some elements still fail, then their geometry is restored to factory parameters.

Light alloys

Although aluminum alloys are quite convenient for welding, they also have their own unpleasant features associated with the quality of casting. When working with the same part, there are areas in which the metal melts very well, while in others it foams and a lot of slag and dirt float up. Experts note that this is often not related to a specific automaker.

A set for treating damage to parts: developing cracks to the base and cleaning the surface. A set for treating damage to parts: developing cracks to the base and cleaning the surface.

Welding on alloys is carried out using special aluminum wire. The cracks are excavated to the base and new metal is deposited on top. Large holes are sealed using high-quality aluminum patches.

Repairing partitions between cylinders in an aluminum block by installing patches. Naturally, the installation of sleeves will follow. Repairing partitions between cylinders in an aluminum block by installing patches. Naturally, the installation of sleeves will follow.

The cost of work depends on the specific case, because the complexity of their implementation is always different. It is very difficult to determine the average price tag, but rough calculations can be made. Welding a hole in the wall between the cylinders today can cost from 5 thousand rubles, and repair by installing a patch can cost from 7–8 thousand. Welding the entire mating surface to restore its plane for an inline four-cylinder block and its head costs approximately 9 thousand rubles. for every detail.

An example of welding the entire mating surface to restore its plane on the cylinder head. An example of welding the entire mating surface to restore its plane on the cylinder head.

Heavy metal

Welding cast iron requires even greater skills from the master. Its high melting point greatly complicates the work and threatens that the metal may crack. Also, this type of welding requires a special, expensive filler wire.

Some cracks in cast iron elements are welded, but sometimes you have to cut out the affected area and apply a patch. The final decision regarding the repair method is determined by the master himself, depending on a host of factors. The patch is cut from a thick sheet of steel.

The fact is that when it is welded into a plane, internal stresses arise, which threaten the appearance of cracks. Slight deformation of the patch helps remove them. Naturally, it is impossible to bend a cast iron part a little without sacrifice, but steel is more ductile.

An example of installing patches in a cast iron cylinder block. I had to install as many as three elements. It's okay, the pressure on the walls in this part of the block is very small. An example of installing patches in a cast iron cylinder block. I had to install as many as three elements. It's okay, the pressure on the walls in this part of the block is very small.

If a breakdown of the walls between the cylinders in a cast iron block is welded, it is very rare, since the welding site is subsequently processed with great difficulty with a cutter. Patches are not applied to such damage. Further development of cracks is stopped by drilling holes at the beginning and end. Next, such a block is sleeved using a special technology using sealant.

Partial welding of the mating surface of the cylinder block. Partial welding of the mating surface of the cylinder block.

Welding of the mating surfaces of cast iron blocks and heads is done by analogy with aluminum elements. The price of the work is the same. But installing a patch will cost more, since an expensive additive is used during welding.

Welding work will also help with such exotic damage. Welding work will also help with such exotic damage.

* **

There is an opinion that welding is an extremely dubious method of repairing engine parts with an unpredictable result in terms of the further service life and overall reliability of the unit.

But if the craftsman is properly qualified, the restored structure will last no less than its factory version, and you don’t have to look far for evidence. Today, many representatives of motorsports, as well as owners of vintage cars or entire museums, resort to this service.

In the first case, the reliability of welding work has been proven in harsh racing conditions, and in the second case, it has been proven by the high and unique requirements imposed by a specific customer.

Even such a terrifying hole in the cylinder of an aluminum block is successfully repaired by professionals using a patch. Even such a terrifying hole in the cylinder of an aluminum block is successfully repaired by professionals using a patch.

We thank INOMOTOR LLC for assistance in preparing the material.

from the archives of the INOMOTOR company and the magazine Za Rulem

How engines are restored using welding

Source: https://ssk2121.com/kak-zavarit-chugunnyy-blok-dvigatelya-elektrosvarkoy/

We weld a cast iron engine block

Any car has a cast cylinder block. The main malfunction of these motor parts is the appearance of cracks, which can be eliminated by welding. How to weld a cast iron car engine block? This procedure is quite complicated. When performing welding work, it is necessary to achieve both the tightness of the product and the restoration of its physical characteristics.

The engine block is the most important component of any modern car. There are many work processes associated with this element that affect the speed and power of the vehicle. Due to its low melting point, cast iron is used to produce this element. Using cast iron, you can cast parts of varying design complexity, even with the smallest elements.

Features of the material used for the manufacture of cylinder blocks

Car engine blocks are usually cast from cast iron. This material is an alloy of iron and carbon, the content of which is 2.14%. This negatively affects the quality of the connection.

Main difficulties of the process:

formation of pores and cracks;
the appearance of hardened structures during processing, the tool used quickly becomes dull;
As a result of overheating, the thin material crumbles.

Cast iron may differ in composition:

gray cast iron is a malleable, high-strength material, easy to process, limited weldability;
white cast iron is a fairly hard and brittle material that can be ground, but cannot be welded.

Features of welding engine blocks made of cast iron

There are many methods for welding metals, but in order to obtain the most reliable connection of individual parts, it is necessary to use proven technologies that can guarantee the effective performance of welding work.

Regardless of the conditions under which a cast iron cylinder block is welded, it is necessary to strictly follow the following requirements for performing this type of work:

Using a metal brush, first thoroughly clean the surface of the product (until it shines).
To remove the oxidizing film and various chemical deposits, the cleaned surface is degreased with special compounds.
The required flux is selected and laid out along the edge to be welded.
At the next stage, the metal is heated to the required temperature using a gas burner. This will take a few minutes, but it is not recommended to start welding right away.
The metal can be joined after it reaches the specified temperature. The cylinder block is welded in small sections - up to approximately 15 cm in one pass.
After creating the seam, the metal must be heated for a few more minutes, gradually reducing the temperature. Rapid cooling of the part or sudden temperature changes should not be allowed.
The created welded joints must be checked: in production this procedure is carried out using special methods, in domestic conditions a visual inspection is carried out.

Cracked car engine block

There are three options for welding cracks in cast iron cylinder blocks:

heating the entire product;
heating only individual sections of it where cracks have formed;
cold welding of a product without preheating.

If, after welding the crack, the surface of the cylinder block comes into contact with other engine parts during operation, it is subject to additional processing. Excess welding metal is removed using sandpaper, a file, or an abrasive.

How to brew a cast iron heating boiler? — Window Guru's Handbook

There are actually not so many reasons why the boiler leaked. First, corrosion may be the culprit. What is corrosion? It is the destruction of the metal structure under the influence of the external environment. Internal corrosion of a gas boiler is caused by the influence of oxygen in the water, external corrosion is caused by combustion products.

The next cause of leakage may be the poor quality of the metal from which the heat exchanger is made and the quality of the seams of its connections.

High pressure in the system or water hammer also cause leaks in boilers. Burnout of the heat exchanger walls also causes a leak.

In some cases, when water is dripping from your boiler and you think your boiler is leaking, it may actually be condensation from the chimney that is flowing down the chimney pipe and onto the burner.

If this situation occurs frequently, a moisture collection cup should be installed in the chimney. When it drips near the circulation pump, the bolt located in its center may have become loose.

Tighten the bolt.

Below we will consider each case separately in more detail and describe what to do if this happens.

Wall thickness and corrosion

Heat exchangers installed in heat generators can be made of copper, steel and cast iron. Each of them has its own pros and cons.

Copper heat exchangers are corrosion resistant and durable if the boiler is used correctly.

Steel heat exchangers are the most common, due to their low cost, resistant to thermal stress due to their ductility, but are more often subject to corrosion.

Heat exchanger corrosion

Cast iron is resistant to corrosion and has a long service life, although they are susceptible to temperature changes and water hammer. Most manufacturers do not use anti-corrosion coatings. But in the latest models of Ferroli gas double-circuit boilers, steel heat exchangers are covered with an anti-corrosion aluminum coating with environmentally friendly internal insulation.

On Baxi units, copper heat exchangers are coated with a special anti-corrosion compound. Protherm, Buderus and Beretta have a cast iron heat exchanger, which is coated with a special anti-corrosion compound. In addition, such a heat exchanger consists of separate sections that can be replaced if they are damaged without completely replacing the heat exchanger.

Wall-mounted boilers Rinnai, Celtic, Bosch are equipped with copper heat exchangers, Vaillant and Navien are made of stainless steel, it is believed that they are less susceptible to corrosion.

Frequent feeding of the boiler has a great influence on the formation of corrosion. Ideally, so-called “dead water”, without oxygen, should circulate in the heat generator. It is oxygen that promotes the formation of corrosion.

If you often have to recharge the heat generator, you should eliminate the reasons for the pressure drop in the unit. Oxygen corrosion forms an ulcer on the inside of the heat exchanger, which is very dangerous. Growing inward, it forms through rust and destroys the heat exchanger.

Workmanship

The strength of the boiler depends on the quality of the welded joints. If a weld seam has cavities or irregularities, sooner or later this seam may leak. The void located inside the seam is considered especially dangerous. Ideally, the seams should be X-rayed, but not all manufacturers do this.

Although heating boilers are pressure vessels and must be subject to increased manufacturing requirements, defects sometimes occur. And, as a rule, it drips from the heating boiler after the warranty expires. It is not always possible to weld the boiler inside and stop the leak.

It depends on how the heat exchanger is designed. In models where a bithermal heat exchanger is installed (the secondary and primary are in the same housing, heat exchange occurs thanks to the two-in-one design), this is problematic. But, even if you did this, as practice shows, this will not help you for long.

High system pressure

Excessive pressure in the system can also cause a boiler leak. There can be many reasons for high blood pressure. The main reason may be a malfunction of the expansion tank, air locks in the system, a clogged strainer, a malfunction of the safety valve, or the make-up tap.

A malfunction of the safety valve is indicated by constantly leaking liquid from the tube. High pressure can not only cause a crack in the boiler, but also cause an explosion. Monitor the serviceability of the pressure gauge and relief valve; sometimes the valve jams due to the formation of a layer of salts on it. Wash it in citric acid.

Heating boiler safety valve

It is necessary to regularly check the correct pressure on the valve and in the expansion tank. When installing an expansion tank, it is necessary to calculate the volume of coolant.

How to calculate - there is a calculation formula, and the average value is -1.5 Atm or 0.2 Atm lower than in the system.

For prevention, do not forget to wash the filters at the inlet and outlet of the heating circuit; after recharging the system, it is necessary to ventilate the batteries.

Burnt out walls

The cause of the leak may be burnout of the combustion chamber wall. Steel and cast iron burn out when carbon evaporates from their composition, so the metal in the combustion chamber becomes thicker.

As a rule, burnout occurs when the height of the combustion chamber is incorrectly set, the burner power is set incorrectly, the burner is not adjusted to minimum and maximum power, or the flame is too high.

Burnout occurs when the boiler is constantly operating at maximum power; this occurs in the case of insufficient insulation of the home or when the heat generator is selected without taking into account the heated area.

When purchasing a boiler, read reviews on the Internet and give preference to reputable manufacturers. It is better to buy a heat generator with a little more power, with reliable flame modulation and entrust the settings to specialists.

How to stop a leak with your own hands

How to repair a leak - the leak repair algorithm is the same for both solid fuel boilers, such as Don, KChM, and gas boilers, for example, AOGV, Alixia 24, Ariston, Deu, Arderia, Electrolux.

Turn off the device.
Drain the water.
Wait until the boiler cools down completely.
We will describe how to remove the heat exchanger below.
Solder and eliminate the fistula.

What does a heat exchanger look like - it is a metal or cast iron body, heated by a burner flame and transferring thermal energy to the liquid that is inside it.

To disassemble it and solder it yourself, you need to remove the front panel, protective casing and combustion chamber protection using a long screwdriver. Then disconnect the sensor wires and the pipelines suitable for the heat exchanger, try not to damage the pipes and pipes, hold them with a wrench.

In order to connect everything correctly later, you should first take a photograph of the inside of the heat generator. Then disconnect the fan and smoke detector. When removing the heat exchanger, do not use force or make sudden movements; do everything with extreme caution.

If you find a gap between the circuits in the tube, it is impossible to repair such a hole; you will have to change the heat exchanger. The heat exchanger cannot be welded; soldering with a gas torch should be used.

Soldering the heat exchanger

In order to do soldering yourself, you must first clean the place where the fistula has formed. This can be done using fine sandpaper. Soldering is carried out using an oxygen gas mixture with solder containing the same chemical elements from which the heat exchanger is made.

Tin cannot be used in this case, since such repairs will again lead to the formation of a fistula after some time. After soldering, a protective coating, for example, a layer of aluminum, should be applied to the problem area.

Prevention of fistula formation

When purchasing a heat generator, carefully examine the quality of the soldering of the connecting seams, both on the water and on the primary heat exchanger; there should be no sagging or unevenness.

Set up the burner according to the instructions in the instructions. To avoid the appearance of fistulas, it is necessary to take timely measures in the presence of high pressure and airiness in the system. Avoid frequent refilling of the system with water; find out the cause of the pressure drop in this case and eliminate it.

Source: https://proosteklenie.com/kak-zavarit-chugunnyy-kotel-otopleniya/