Straightening the shape and size of a deformed bonnet includes two main operations: preliminary straightening to relieve shock stress and final straightening of small irregularities.
Necessary
Special levers and clamps for repairing dents, chisels, wooden mallets or hammers with rubber or plastic strikers, anvils, straightening saw. Gas burner (if equipped)
Instructions
Step 1
Remove the hood from the vehicle. This is necessary for the convenience of work. To do this, detach the stop from the bracket and unscrew the bonnet fastening nuts.
Step 2
Before starting work, remove the paintwork from the front side, the anti-corrosion and noise-insulating coating from the inside of the hood.
Step 3
Repair should be started from surfaces with greater rigidity: folds, stiffeners, reinforcements, fold lines. It is necessary to straighten it with light frequent blows with a low metal drawing. It is necessary to assess the quality of straightening and straightening visually or by quickly stroking the surface with the palm of a gloved hand. Convex and concave surfaces are monitored visually, when viewed from an angle or from the side. Flat surfaces are controlled with a ruler.
Step 4
It should be borne in mind that the inflection lines concentrate the maximum internal stresses, which interferes with the restoration of the hood shape. A shallow and small dent is recommended to be corrected by applying scattered blows to the top of the dent. Large dent - smooth out gradually, starting at the edge of the fold. The blows should be light, frequent, from the periphery of the dent to the center. Under the surface at the edge of the indentation there should be a support with the most suitable curvature of the surface.
Step 5
The dent can be removed by heating and shrinking the metal, if a gas burner is available. This method is suitable for removing dents with significant metal drawing. To do this, remove the paint and anticorrosive coating from the place of heating, lay a damp cloth around the heated space. Heat the metal at a point 8-10 mm in size to a cherry color and cool with a damp cloth. A greater effect can be achieved in combination with light hammer blows. The number and location of hot spots is determined by the shape of the dent. Straightening in combination with heating can be used only with practical experience in performing this operation.
Step 6
Correct the hood in a hard-to-reach place should be done with hammers, a plate and specialized levers. The choice of lever depends on the location and nature of the dent. For example, flat levers should be used to remove dents under the amplifiers. Restoration of stamping and stiffening ribs is carried out using a chisel and a base plate.
Step 7
It is possible to finish the hood before painting only after thorough straightening. Repair small cracks by applying a polyester filler followed by a straightening saw. Alternatively, apply solders and then remove the build-up with a straightening saw. It is unacceptable to eliminate small irregularities by removing the metal layer with a straightening saw.
Step 8
Work should be done with proper quality. The shape of the face surface of the refurbished hood must match the shape and geometry of the new one. The clearances of the bonnet with adjacent body panels must be of the same size and the same around the circumference. Cracks, metal holes welded, corrosion removed, welds processed flush with the metal. The thickness of the layer of polyester putty after processing should not exceed 2 mm. The bonnet lock should be adjusted if it does not lock or unlock properly after repair.
Step 9
It is necessary to install the hood on the car after applying the paintwork, anti-corrosion and anti-noise coating, which was removed before starting work.
