Where does the rust come from?
A car enthusiast usually sees corrosion on the outside of the body, which started with chipped paint. Once the stone has broken through the metal, the steel will begin to corrode. When oxygen reacts with iron, rust is formed – Fe2O3 But beware, this happens where the metal is left bare.
And why does the car rust from the inside?
Everyone saw rusty thresholds, spars, doors. The fact is that in such places moisture lingers for a long time. It is especially dangerous where two metal plates are joined by seaming (doors) or spot welding. Under the action of vibration, the two surfaces begin to move and the coating cracks. Moisture-carrying oxygen reaches the bare metal, and — hello, corrosion.
Therefore, first of all, it is necessary to protect such joints – mainly in the lower part. After all, the water flows downwards and accumulates there. For example, on the hood, the leading edge rusts from the inside – especially on those models where it is curved in the shape of a beak. Places for the accumulation of moisture – in bulk.
The same happens in the doors, including the tailgate of hatchbacks and station wagons. The same moisture traps are formed in the lower part of the thresholds, where contact welding connects three elements in one place.
All cavities have drainage holes for draining water, but the problem is that they get clogged over time. Therefore, the first and easiest way to slow down corrosion is to clean the drain regularly.
There are always drainage holes at the bottom of the door. And here are the mounting holes for the seal.
What must we do?
You can protect the most vulnerable places for corrosion yourself. It is enough to apply an anti-corrosion agent to the desired voids with the help of purchased aerosol cans with tubes with nozzles at the ends. The alternative is a not very complicated homemade atomizer.
It is best to process cavities in warm weather. It is desirable that it was dry for several days before that. In the cavity of the doors, hood and trunk lid, the medicine can be easily applied through the existing drainage holes. You just need to pour generously and do not forget to close the hood immediately after the procedure so that the preparations flow to the leading edge.
More difficult with thresholds. Access to the outer cavity can be provided from the ends (from the wheel arches) or through the drains, which are not wide enough for the passage of the pipe on all machines. If there is no access, then a small diameter hole should be drilled from below, pre-prepared with rubber plugs. But at the threshold there is also a second, internal cavity. In most cars you can get there by removing the sill trim in the cabin.
All these works are not particularly time-consuming and can therefore be carried out independently once every one or two years, in the summer.
It is useful to treat the air inlet duct with an anti-corrosive agent.
On some cars, removing the sill trim gives us excellent access to both the inside and outside of the sill section. Creative approach is important – look for options on your car.
Can be smeared
Working with mastic at the bottom is more gloomy. They should be performed qualitatively once, and then the coating should be updated if necessary.
You can independently protect the surface of the wheel arches from sandblasting and corrosion by simply jacking up the car and removing the wheel. You just have to remove all the dirt first. It is necessary to wash, dry and only then apply a layer of mastic.
But the soundproofing of the wheel arches will improve and the pebbles will no longer strip the coating from the metal. Without an elevator and viewing moat, a motorist can process the lower part of the thresholds in the same way, also protecting them from sandblasting. If there is an inspection trench, you can treat the entire underside of the car with anti-rust mastic, but keep in mind that it must be pre-washed and dried. Therefore, it is better to carry out a full processing of the bottom at the service.
The surface of the wheel arch itself can be coated with a layer of anti-corrosion and anti-noise mastic.
What else to protect?
Many modern cars have box section front and rear subframes that are welded from thin pressed steel. The paintwork is very weak. There are many examples where the body of the car is still quite resistant to corrosion and the subframes are “rotten” through and through, so that the wishbones have nothing to hold on to. It makes sense to process them in advance.
In general, if you’ve done it yourself, research on internet forums for your model what rusts the car the most. And get creative with the task and evaluate in which cavity moisture can accumulate, where the plates have been spot welded and there can be gaps between them.
- What are anti-corrosion agents? What are the rustiest cars? Where to make anikor? Which drugs? Here we’ve collected answers to the most common questions about corrosion (and the opinions of car manufacturers).
- “Behind the wheel” can also be read in Telegram.
It is possible (and even necessary!) to protect the most vulnerable to corrosion spots on the body itself.
Do-it-yourself anti-corrosion – detailed instructions “Driving”
Source: Z R