Contents: Safety rules for bodywork ↡ Cars with air conditioning ↡ Drying of paint coating ↡ Removal the anti-corrosion coating…↡
The Mercedes A-class car has a monocoque body. The body base, its sides, roof and rear wings are welded together. Therefore, serious body repairs, as well as replacement of the front and rear windows, should be entrusted to a workshop.
The hood, trunk lid or tailgate, doors and front fenders are bolted together and can therefore be removed and replaced without any problems. However, in this case, it is essential to maintain the required clearances during installation, otherwise, for example, the door may knock or increased air flow noise may be observed during movement.
The gap must always be parallel, which means that the distance between the body parts must be the same along the entire length of the gap. Permissible deviations must not exceed 1 mm.
Attention! If work on the vehicle's electrical system is to be performed as part of the bodywork, be sure to disconnect the negative (-) battery terminal, see the relevant chapter. Work with electrical equipment includes even simply disconnecting an electrical wire.
Attention! Numerous elements of the body trim are secured with so-called expansion clamps. Expansion clamps damaged during removal should be replaced, and new ones should be installed in place of the missing ones.
Safety rules for bodywork
To perform welding work, you should use a contact butt welding machine.
The use of gas welding is only permissible in cases where contact butt welding is impossible, for example, due to insufficient space between body parts.
Article was obtained from the portal MercedesMAN
When performing welding or other work accompanied by the formation of sparks, the battery should be disconnected by removing the terminals from the terminals and carefully insulating both terminals of the battery.
When performing welding work near the battery, it must be removed.
Attention! If the radio has an access code, it is deleted when the battery is disconnected. After connecting the battery, the radio can only be turned on after entering the required code or by using the services of a Mercedes workshop or the manufacturer of the radio. Therefore, before disconnecting the battery, check and write down the entered code.
Warning! Bodywork involves strong vibration, such as hammer blows. For this reason, always turn off the ignition and disconnect the power cable terminals from the battery terminals.
Otherwise, the airbag may deploy. Read the safety precautions for handling airbags.
Cars with air conditioning
It is prohibited to weld or solder parts of a filled air conditioner with soft or hard solder. This also applies to welding and soldering work in general, if there is a risk that the air conditioner parts will heat up.
Warning! Do not open the air conditioner coolant circulation system. Coolant may cause frostbite if it comes into contact with skin. If coolant comes into contact with skin, rinse the area with cold water for 15 minutes. Coolant has no color or odor, and is heavier than air. If you are in a pit to work on the underbody of a car, a coolant leak from the air conditioner may cause suffocation, especially since the coolant is odorless and colorless, so a person does not feel the danger.
Drying of paint coating
During repair work, heating of the car in the dryer or its chamber is allowed within the limits of no higher than +70°C. Otherwise, the electronic control devices may be damaged. In addition, high pressure is formed in the air conditioner, which may lead to a rupture of the unit.
Removal the anti-corrosion coating from the bottom
To protect the bottom and wheel arches from corrosion, they are coated with a polyvinyl chloride compound.
Polyvinyl chloride protection in repair areas can be removed with a metal brush or by heating it with a hair dryer to a temperature of +180°C and removing it with a spatula.
Attention! When the PVC layer is heated above +180°C, hydrochloric acid is formed, which promotes the formation of rust, and harmful vapors are formed.