Features of repair and overcooking of the VAZ 2112 underbody

Design Features

The bottom of all modifications of the family was made of rolled steel. Additionally, to increase strength, stiffening ribs are made.

Important! Since the frameless design involves accepting the load from all body and transmission elements, it is the condition of the bottom that determines the functional readiness of the car.

Cars of different body types have different overall dimensions. At the same time, the wheelbase of all modifications is the same - 2,492 mm. The size and shape of the bottom on all machines also has no fundamental differences.

Family service experience indicates that most often - in 9 cases out of 10 - repairing the underbody of a VAZ 2112 begins with checking the condition of the body side members. Corrosion processes require their strengthening.

Boil the bottom of the VAZ 2110

I have a typewriter. It’s old, but it’s dear to me—I build on it. It still starts in any frost, drives and doesn’t break down. But it has one problem - it has begun to rust. It’s still too early to cook the body, but the bottom and bottom of the trunk—things have already begun to fall out. The holes are big, in short.

I would like to digest it, cover it with an anti-corrosion coating so that rust does not appear on it until at least another three years.

What can you recommend? How much could it cost?

Best regards, Sergey Tikhomirov.

Bottom repair Hello!

Disassembly/assembly of the interior, welding of the bottom and trunk, anti-corrosion treatment - RUB 30,000. I think it can be done.

The condition of the car largely depends on the body. The suspension can be “rebuilt” by replacing worn and faulty parts. The engine's attachments are also repaired or replaced; in severe cases, major repairs or complete replacement are performed. Body work determines the appearance of the car and, in many ways, its service life.

New VAZ 2110 from the showroom with an ideal body

When is repair required?

The first copies of the tenth family had a characteristic feature - the paintwork on the windshield frame peeled off at the top, starting from under the seal. Then this disease was overcome by changing technology, but the weaknesses remained.

Already on five- to seven-year-old cars, corrosion on the sills is very likely, and ten-year-old cars necessarily require monitoring of the bottom, arches, and side members.

They accelerate the appearance of rust and through corrosion, damage in road accidents followed by incomplete or unqualified repairs, difficult operating conditions on bad roads in winter and in bad weather, storage in conditions of high humidity.

Regular anti-corrosion treatment done at a service center or with your own hands will help extend the life of body parts; it is especially necessary for the hidden cavities of the sills and side members, this power “skeleton” of the car.

The bottom is corroded on both sides. From below he is attacked by dirt and water from the road. If the anti-gravel coating is damaged, the first spots appear literally within a year; after 2–3 years, with intensive use, corrosion becomes through.

Through corrosion of the bottom

In the cabin there is a carpet on the floor, under which there are layers of vibration-insulating and noise-absorbing materials. If water or snow gets into the bottom trough, for example from shoes, the coating gets wet and does not dry well. Increased constant humidity leads to corrosion of the bottom from the inside of the cabin and the need for repairs. To prevent this, use rubber mats with sides, and make sure that no water gets into the interior during rain or when washing.

Corrosion due to moisture under soundproofing material

A rotten bottom is revealed when viewed from below; under a layer of putty or anti-gravel, the holes may not be visually noticeable, but light blows with a hammer or pricks with an awl will immediately reveal the defect. Corrosion most often appears along the sills and in the driver's and front passenger's feet.

In the cabin, poor condition of the bottom will be indicated by sagging of the floor under your feet under load, in extreme cases, the breakdown or impossibility of fixing the driver's seat. And, of course, there is a frequently encountered situation when, when lifting a car on a jack, the special thrust pads for the jack break due to corrosion.

Preparation for repair

Bottom repair can be done with your own hands, but this requires a good tool, a suitable room, free time, skills and desire.

When working with metal, you cannot do without welding. It is optimal to use a semi-automatic welding machine with wire and carbon dioxide; compared to gas and electrodes, it is much simpler, more convenient and of better quality. An angle grinder will be needed when removing rotten floor fragments, for fitting parts and patches during welding work, and for cleaning seams and surfaces before processing and assembly.

Semiautomatic welding machine with wire for welding with carbon dioxide

You also need stands for the car, for example, four pieces of the “diamond” type. The rest of the tool is standard and more common. The materials you will need are welding wire, joint mastic, anticorrosive, sandpaper, primer, paint, soundproofing sheets.

For repairs, the car is driven indoors and placed on stands. It must be possible to work comfortably and safely from below the bottom. The battery and electronic control unit are turned off to prevent damage during welding. The doors are removed; to maintain the rigidity and geometry of the body, spacers in the doorways are very desirable.

The next stage will be lengthy and responsible - disassembling the interior. Here you need to dismantle the seats, remove the floor tunnel lining, air ducts, remove the carpet, move the wiring harnesses aside, scrape off or beat off the noise. If it becomes necessary to change the entire bottom or weld in a floor panel, then you need to remove the torpedo and the beard - access to the engine shield must be open. It is recommended that all fasteners be carefully assembled, packaged and labeled to facilitate assembly work.

Welding work

When the floor is completely visible, you can decide on the scope of repairs. At best, you can do without replacing parts. All areas of corrosion must be thoroughly cleaned down to “healthy” metal and, if necessary, reinforced with patches. But usually this option is unlikely.

If there are through holes or loss of rigidity, the corresponding body part must be replaced. For VAZ models of the tenth family, the body floor consists of:

• floor panels;
• threshold extensions;
• front spar extensions;
• support platforms;
• connectors;
• cross members.

To replace, the old part is drilled out at the welding points or cut off with a grinder. Remember that there are fuel and brake lines running underneath the underbody on the driver's side. Disassembling them on similar machines is problematic; it is easier to cut them off and replace them with new ones during installation.

If the floor panel of the VAZ 2110 is in very poor condition, then the entire bottom assembly is replaced, in which case additional dismantling of the exhaust system will be required. If it is necessary to replace the thresholds at the same time, then they are changed one at a time with geometry control, and only then the floor is re-welded.

Marking, cutting out the old, fitting the new requires attention and accuracy, and the welding itself also requires an assistant. The bottom is started from below, tacked, the main welding is not done with a continuous seam, but in increments of 4–5 cm.

Final processing

After welding is completed, the seams must be protected from corrosion.

The metal is cleaned from scale to a shine and coated with joint mastic. All surfaces are primed, then painted in the main color, without selecting paint. The selection of quality materials and careful processing will guarantee successful corrosion resistance.

A layer of mastic and anti-gravel coating is applied on the outside. From the inside, after adjusting to size using scissors and heating the bitumen layer with an industrial hair dryer, sheet sound insulation is glued.

Now all that remains is to assemble the interior using the fasteners packaged and signed during disassembly.

Repairing or replacing the underbody with your own hands is within the capabilities of most car enthusiasts. If you want to save money, feel confident, learn new skills, and maybe hang out with friends in the garage and take a break from family worries, then go for it. Do-it-yourself car repair is necessary, useful, and affordable.

VAZ-2110 is a very cheap and easy to maintain car. But one of its main “sores” is the body. Unfortunately, it is poorly protected from corrosion. After only two years of operation, “bugs” form on it. If you continue to ignore the problem, through holes will appear. Rust forms everywhere: on the arches, fenders, and at the bottom of the doors. But the most vulnerable spot of the VAZ-2110 is the bottom. See photos and description of the repair process later in the article.

How to find rust on the bottom

A prerequisite for trouble-free operation of the 12th family hatchback is periodic inspection of the car for corrosion from below. Even cars from recent years of production need additional processing.

It is better to carry out a comprehensive inspection of the bottom. Among the main detected defects are:

• peeling of the anti-corrosion composition;
• the appearance of local foci of corrosion (jack attachment points, thresholds);
• presence of fires on the interior side.

You should not delay diagnostics, since if the iron is damaged by 70% of its thickness, restorative repairs are difficult to carry out. It is more convenient to do diagnostics when lifting the car on a lift or driving into an inspection hole. It would be a good idea to look under the upholstery and from the interior.

Let's get to work. Preparation

So first we need to prepare the car. We drive it into the garage and dismantle the interior. It is advisable that the room has an inspection hole. Depending on the scale of the work, we will need to remove one or more seats, as well as part of the carpeting, which comes standard from the factory.

At the next stage, we cut out the rotten sections of the floor with a grinder. We also cut out the metal whose thickness is less than the factory thickness - after repair it can rust again.

Please note that fuel and brake pipes, as well as the exhaust system, run under the bottom.

Next, carefully clean all the seams with sandpaper. You can use a special drill attachment. The remaining traces of rust are treated with a zinc converter. Be careful: he is very aggressive. Therefore, we work exclusively in protective gloves.

When choosing to repair the bottom yourself, you need to prepare tools and materials. For experienced craftsmen, a complete replacement of a part takes at least 3-4 days; the cost of work at a service station averages 45–50 thousand rubles. To work you will need:

1. Bulgarian. Using an angle grinder, the corrosion plaque is removed from the bottom, parts of the patches are adjusted, cut off, and welding seams are aligned.
2. Welding machine. It is recommended to boil the iron body and bottom, in particular. Semi-automatic welding with wire and carbon dioxide is suitable. You can use gas welding and 3 mm electrodes, provided you are skilled in such work.
3. Electric drill for drilling spot welds.
4. It is not recommended to carry out underbody repairs in a pit - it is inconvenient; it is better to use stands, a lift or skids; in some cases, the car is turned over on its side.
5. Sound insulation sheets.
6. Anti-corrosion set: mastic, R-80 sandpaper, primer, auto enamel.

Preparatory work step by step:

1. Disconnect the negative terminal from the battery or remove the battery.
2. Drain the fuel from the tank.
3. Disconnect the electrical wiring from the door power windows.
4. Remove the doors, marking the fastener locations on the body.

Before dismantling the doors, it is necessary to insert iron spacers into the openings or weld a channel, this will ensure that the geometry of the body is preserved if the center pillar reinforcement is rotten and there is a possibility that the roof will fall or bend in half.

Dismantling the interior

Replacing the underbody involves work inside the cabin and under the car. Dismantling the interior is carried out in steps:

1. Pull out the seats.
2. Remove the interior trim by unscrewing the moldings.
3. Pull out floor coverings and carpets.
4. Remove air vents.
5. Remove the sound insulation layer and additional anti-vibration pads.
6. Disconnect all internal wiring, twist the cables into a bundle, and remove the fasteners.
7. Remove the dashboard to open access to the engine compartment if you plan to completely replace the bottom.

Causes of rust and preventive measures

Among the reasons for the acceleration of corrosion processes on the bottom of the model with index 2112 are:

• storing the car outside during temperature changes and high humidity;
• operating a vehicle in difficult road conditions;
• water getting under the interior trim.

Almost any car over 7 years old is monitored for corrosion.

Overcooking the bottom of a VAZ 2110

Often, on a VAZ 2110 car, it is necessary to digest the bottom, because the quality of paint and iron on VAZ cars leaves much to be desired. For information on how to fix this problem and digest the bottom, see this article.

What do we need for work?

• Welding machine;
• Angle grinder;
• Car stands;
• The rest of the kit is standard and includes such components as anti-corrosion solution, mastic for seams, welding wire, sandpaper, primer, soundproofing sheets, paint, etc.

Causes of rust and preventive measures

The procedure for carrying out repair work

All work is conventionally divided into 3 stages: preparation of the bottom, replacement of the entire element or re-welding of individual parts, reassembly of the dismantled parts.

Tools and materials for work

Work is carried out after changing into dry clothes suitable for welding work. Before starting, prepare tools (grinder, welding machine, drill) and consumables. You will need new soundproofing sheets, as well as:

• mastic;
• primer;
• sandpaper;
• protective enamel.

After disassembly, it will become clear whether the repair will include additional metal parts, or whether the entire bottom of the VAZ 2112 will need to be welded.

Safety precautions

Since the work involves welding, fire safety of the work must be ensured. To carry out proper repairs, you should turn off the power to the car and drain all the fuel from the tank. For convenience, the doors in the cabin are dismantled, having previously de-energized the windows. In order to preserve the geometry of the body, after removing the doors, the openings are strengthened by installing spacer elements.

Note! Make sure the vehicle is securely fastened.

Initial work before restoration

Primary work involves a number of sequential operations:

• mastic;.
• guide;.
• sandpaper;.
• protective enamel.

After disassembly, it will become clear whether the repair will consist of additional steel parts, or whether the entire VAZ 2112 base will need to be prepared.

1. removal of seats, as well as interior leather;
2. removal of moldings (if installed);.
3. removal of air ducts;
4. elimination of sound insulation, as well as exhaust gas insulation;.
5. Getting rid of downloadable things.

In the case of the proposed replacement of the low station wagon with a VAZ 2112, it will certainly be necessary to get rid of the main passage from the dashboard. This will certainly facilitate access to the engine compartment.

Replacement of structural parts

When performing work, take into account that the components of the bottom are:

• support platform;
• composite panels;
• threshold extensions;
• amplifiers of side members and cross members;
• connectors.

When carrying out troubleshooting, it becomes clear whether it is possible to repair a particular body element or whether the entire body will need to be replaced. In the case of fragmentary repairs, it is necessary to drill holes in the places where the part is attached using spot welding. The body element itself will need to be cut out with a grinder.

Welding work when repairing the bottom

Readiness for welding is checked according to the following algorithm:

• grounding the device;
• complete serviceability;
• effective room ventilation.

First, the spot welding spots are drilled out and the bottom is cut out along the contour. A new element is inserted into the prepared area and welded around the perimeter in increments of 20-30 mm. The seams are processed. The best results will be achieved when using joint sealant.

Is it possible to work on the bottom and sills at the same time?

People often ask about the simultaneous replacement of the bottom and sills. These operations are performed simultaneously. The factory repair kit for the side parts is installed first.

Complete replacement of the bottom

Before starting work, it is necessary to disassemble the elements of the exhaust system. From the point of view of the sequence of operations, a complete replacement is no different from a partial one.