- Practical advice
- Neutralize the rust on the car
- Prepare the funds
- Scratch to the sound metal of the body
- Deburr and soften
- Polish with a nylon brush
- Treat deep rust stings
- Clean and treat with rust remover
- Apply polyester sealant
- Sand and apply a second coat of putty
- Spray acrylic primer
Corroded sheet metal and blistered paint... the wear of the weather, the humidity and the de-icing salt have marked the body of this car in places. Localized repairs can refurbish it.
The application of the painting follows the preparation of the funds.
If there are few rust spots to repair, an aerosol can be used to touch up. If not, it is better to repaint the whole car (as in our example).
The reference of the original paint is often indicated on a part of the hull (trunk, door pillar...).
Take into account hue variations over time.
Neutralize the rust on the car
The vehicle has not suffered shocks, the body is not to be taken in its entirety. This involves performing small, localized repairs to treat corrosion attacks. Once chewed and primed, they will be put back into painting.
The most important repair is near the hinge of the left front door, at the level of the reinforcement rib. Rust has developed in depth over a wide area. The ideal treatment would be to sand the area, but this requires special equipment (sandblasting gun). Otherwise, the rust is neutralized by a mechanical process, supplemented by a chemical treatment.
The coarse sanding of the rusted part can be done with the grinder by working very superficially, without pressing, because the sheet is thin. An abrasive soft disc of grain 40, mounted on a drill, is also suitable. To access the corners more easily, use a flat nylon brush loaded with abrasive particles. It allows to rust the bottom of rib.
It is difficult to completely rid the metal of deep rust stings. This is why a chemical treatment is added to the sanding. Hard to find commercially, phosphoric acid is the basis of all rust-destroying products available in supermarkets. After its application, the points become black. A passage with the rotating nylon brush eliminates them. Rinse thoroughly with water.
Prepare the funds
The surface must be very clean. The simplest is the use of an antisilicone cleaner or cellulosic thinner.
● The Spies Hecker two-component anticorrosive product (8583) is mixed in the proportion of 4 to 1 with a liquid hardener (3050). For a gravity gun, the nozzle is 1.4 to 1.5 mm and the pressure set at 3 to 4 bar. It is possible to choose another brand or even to use an aerosol, provided that the product is anti-corrosion. After masking the contours of the surface to be treated with newspapers and masking adhesives, the metal is covered in several passes.
● The preparation of the repair putty involves intimately mixing about one tablespoon of polyester paste for a hardener coffee bean. It is applied without delay to the spatula in consecutive layers. After twenty minutes of drying, the sanding begins with 80 grit sandpaper, then 150 and finally 240. The result is correct when the surface is smooth: the hand should not feel hollow or bumps.
● Then apply an acrylic primer (aerosol) that will be sanded with 600 paper and 1000 paper. The surface is ready to paint, aerosol or spray.
Scratch to the sound metal of the body
Corrosion is important on this side cheek, adjacent to the door hinge.
To evaluate the extent of the attack, scrape with a beveled spatula to find the healthy metal.
Deburr and soften
Corrosion is marked but not perforating.
Attack the surface with a disc to debark, slightly inclined and without pressing. The passes must be very superficial.
Soften the edges.
Polish with a nylon brush
Polish the metal. A nylon brush loaded with abrasive particles mounted on drill gives good results, but be careful not to press too hard. Friction warms the nylon that melts.
Treat deep rust stings
There will always remain deep rust bites that may eventually attack the paint. Treat with a brush dipped in a rust destroyer. Rinse with water.
Clean and treat with rust remover
Clean the surface with cellulosic thinner and protect the healthy areas with paper and adhesive.
Spray anti-rust primer in a cross coat.
Apply polyester sealant
Apply the polyester putty to the plastic spatula. It is prepared by carefully kneading the dough and the hardener.
Press and apply with close-up keys.
Sand and apply a second coat of putty
Sand according to the curve of the side cheek. Use abrasive paper 80 placed under a hold. If necessary, apply a second coat of putty and finish with dry paper.
Spray acrylic primer
Spray the acrylic primer to the bomb.
Overflow a bit on the fitting.
After drying (1 h), sand with water 600 and 1000 paper. The surface is ready to paint.