Fortunately for manufacturers (and unfortunately for car enthusiasts), the service life of modern cars is far from ideal. If some 30-40 years ago cars were produced to last for decades (many car owners still have Mercedes from the 80s and 90s in their garages, which have survived everything possible), then modern cars are designed to last a lifetime from 5 to 10 years maximum and require auto repair.
And the first blow is taken not by the unit or suspension, but by the body. Already after 5-7 years on foreign cars (and on domestic cars after 3 years) pockets of corrosion begin to appear. If this problem is not corrected immediately, it will begin to progress and the body will collapse right before our eyes. In this article we will tell you how to weld a body with your own hands and what equipment you will need for your car in order to carry out repairs more or less efficiently.
Which welding machine to choose
A welding machine for a car is 50% of your work. Ease of use and speed of operation depend on its correct choice. We invite you to compare a semi-automatic and a conventional inverter.
Let's start with semi-automatic machines, since these are often what you will see at service stations or in private car repair shops. Semi-automatic welding is very convenient, especially in hard-to-reach places, and the body has plenty of such places. To operate a semi-automatic machine, you will need wire and a protective gas (most often argon or carbon dioxide). The gas protects the seam from oxidation and the negative effects of oxygen.
What are the advantages of a semi-automatic? Well, firstly, the quality of the seams. They can be of different widths, but are always very neat. You can also adjust the wire feed to suit your skills. If you do not have the opportunity to cook with gas, then you can use a special wire consisting of flux.
But, like any welding technology, it also has its disadvantages. First of all, if you decide to use electrodes for a semi-automatic machine instead of gas, then be prepared for a high price tag. And if you still decide to use gas, then you need to purchase a reducer for it, with which you will need to reduce the pressure. Plus, setting up the gearbox requires skill.
Now let's talk about inverters. Is it possible to weld a car using inverter welding instead of a semi-automatic one? Of course you can cook it. We declare this with full responsibility. To work you will need a welding machine and electrodes.
First, about the advantages. Inverters come in a variety of different types; the choice is truly great. Manufacturers offer compact budget models and professional units. Inverters are also capable of operating in conditions of unstable network voltage. It is also extremely easy to ignite an arc using an inverter. For this reason, even for a beginner, welding a car with an inverter will not be a problem.
Now about the disadvantages. You will have to look for very thick electrodes on sale (up to 5 millimeters in diameter), but they are rare and are not cheap. In addition, if you use such electrodes for welding a body, the seam will be far from ideal.
So which welding method should you choose? We can say one thing: if the quality and beauty of welding is important to you, then definitely choose the semi-automatic method of welding a car. With such a welding machine, you will be able to do the job very well and, if you have the skills, you will make a seam no worse than in a car service. Well, if the beauty of the car is not in the first place, choose inverter electrode welding.
Now you know how to choose a welding unit for working with a car. Evaluate all the pros and cons of a semi-automatic device and an inverter, make your choice.
The nuances of welding body metal
The main task is to correctly select the diameter of the welding wire, which directly depends on the thickness of the metal being welded. The welding current is selected based on the selected diameter. Welding modes are approximately indicated in the table:
| Thickness of welded metal, mm | Welding wire diameter, mm | Current strength, A |
| from 0.5 to 0.8 | 0,6 | 10÷30 |
| from 0.8 to 1.2 | 0,6÷0,8 | 30÷100 |
| from 1.2 to 1.4 | 0,8÷1,0 | 45÷100 |
| from 1.4 to 2.0 | 0,8÷1,2 | 45÷120 |
If it is necessary to weld metal of greater thickness, then it is necessary to use the data specified in the manufacturer’s passport or on the unit label.
Before starting welding work, the device must be checked for functionality. The electrical network must provide stable current characteristics. An inverter-type semi-automatic machine is the most reliable in this regard, because it works in networks where the voltage does not drop below 150 V. The welding process should not be accompanied by the release of smoke before it begins, as well as crackling sounds and vibrations during the body work process.
Attention! The open circuit voltage should be as high as possible. This makes it easier to initiate an arc upon contact with metal.
Precautions
Don’t think that if you brew in your garage, you can neglect safety precautions. You must carry out any welding work in special equipment: clothing made of thick material, a mask and gloves. This is the minimum set. If you are welding parts in a garage with a metal floor, then the shoes should be rubber.
The welding machine must be grounded for welding. To repair automotive hardware using an investor, you will need a high-quality holder. A low-quality one simply will not withstand repeated clamping and will deform the insulation.
Also, your garage should be ventilated, and even better if it has forced ventilation. If you do not follow this rule, gases may accumulate in the room and you will become poisoned.
Effective use of welding for body repair
In order for body work to be carried out quickly and allow you to make a good profit, two basic conditions must be met:
- Availability of a staff of professional specialists. The successful solution of this problem depends only on the management of the service station. Therefore, there is no point in considering it in our case.
- Availability of effective equipment for welding car bodies. But we have been helping our clients solve this problem for many years. GARO LLC sells devices that are manufactured under reputable brands and are distinguished by a whole range of advantages. Among them are the low cost of welding car parts, high quality welds, and reliability. Our catalog contains welding machines that really allow you to make your business successful.
How to weld a body with a semi-automatic machine
We chose a semi-automatic machine because with its help the seams will be of better quality and more durable. In our work we will use a welder from BlueWeld model 4.135 (you can use any other welding machine for cars). Also in our arsenal are filler wire with a diameter of 1 millimeter, sandpaper, a reducer (with its help we will reduce the pressure), and a gas cylinder (a 20-liter cylinder is enough for us).
First, we clean the metal surface from rust and dirt. This can be done by hand using sandpaper, but if you have a sander, use it. Next you need to press the parts tightly against each other. To do this, you can use any clamps, bolts, or even temporarily connect them with self-tapping screws. Now we need to connect our reducer to the gas cylinder. The photo below shows how to do this.
Next, you need to feed the wire into the welding machine and insert the end of the wire into the feed mechanism. The photo below shows the wire feeding process.
Now unscrew the nozzle on the burner (we did this using pliers), thread the wire through the hole and screw the nozzle back on.
So, everything is ready. You need to configure the device. We set it to straight polarity because our wire is copper. If the car is welded with regular wire, then set the polarity to reverse.
We connect the device to an outlet. We press the wire feed button, and at the same time the gas supply should begin. We begin to form the seam. If the seam is short, you can make it continuous. If the seam is long, then first we form “points” at different joints. Then we make several short seams between the points. There should be 10 cm gaps between the seams. Let the seams cool. Now let’s cook the remaining sections.
Seam processing
We figured out what is needed to weld a car body. But after completing the work, you also need to treat the seams so that they do not cause corrosion.
An economical option is to cover the seam with auto sealant. For greater savings, you can choose a one-component sealant. If appearance is important, the sealant can be leveled with a spatula, sanded and painted. This is the most budget option.
If you are one of those who believes that car welding work must be of high quality (even if done with your own hands in the garage), then you can use special preservatives that are applied to the seams using a pneumatic sprayer.
Areas most susceptible to rot that need welding
After the expiration of the period described above, the car body most often begins to rot. This may not have any impact on performance at first, but over time the rot can cause the car to break down completely.
If you purchased a car that is more than ten to fifteen years old, you need to carefully examine its body. Areas affected by rot must be repaired as soon as possible. Ideally, you need to completely change the car body, but not everyone has the means to do this.
To repair rotten body parts, nothing more than welding is used. With its help, you can repair the affected area without much difficulty. The final result is in no way inferior in characteristics to the factory state of the body.
Most often, car parts such as doors, areas under the wings and bumpers are the first to begin to rot. These places are most susceptible to pollution during operation. Also, doors are largely subject to rotting due to the human factor - the driver and passengers step on the thresholds with dirty shoes, etc. In addition to the above parts, the interior area of the trunk, precisely the place where the spare tire is located, can rot. The fact is that most drivers put the wheel there without cleaning it first.
Most often, large areas of rot can only be completely removed through major repairs. In specialized centers, professional equipment is used for this. This process is also expensive; if you do not have the necessary funds, then you can easily weld the desired area yourself. However, before you begin the repair, you need to thoroughly understand how to perform welding work, as well as which of the many welding methods to weld a car body.
