Smaller scale body repairs, where damaged panels do not need to be replaced, can often be carried out by realignment work. Whether the repair is economical however, often depends on the accessibility of the affected body area.
During damage assessment, the following technical points must be taken into account:
Hollow leveling can only be used on areas which are accessible from the rear.
During hollow leveling, the dent is removed from the inside a using suitable panel beating tool and applying knocking or pressing movements. High spots around the edge of the dent area are flattened with blows from the aluminum or wooden headed hammer.
The usual tools are for instance hammers of various designs, dollies, levering irons and various spoon irons. The correct choice of tool is made depending on the shape of the dent and the access which is possible.
Dent removal using hammer and dolly
Panel beating can only be performed using a hammer and dolly if access can be gained from the rear side.
The purpose of the dolly in this case is to transfer the force of the impacts from the hammer to the steel panel which is in between. As this is done, the deformed body panel is smoothed (dressed) and the tension fields in the body panel are removed.
The favored tool for this repair process is the aluminum hammer and as opposite support the universal hand dolly. To rectify minor panel damage, the box file should be used as opposite support. Because of its serrated surface, the box file prevents normal stretching of the body panel which would otherwise occur.
Dent removal from the outside using the slide hammer
The slide hammer technique is mostly used when a dent is not accessible from the rear, or a relatively large amount of disassembly would be needed to make it accessible.
By welding pulling rings or pulling electrodes into position using a special welding gun, dents can be removed from outside using the slide hammer.
Dynamic puller with counter bearing
The repair possibilities are much greater than with the slide hammer method. Because of the versatile puller and the variable counter bearing, a wide variety of damage can be worked and rectified using this repair method.
1
-
Puller with counter bearing
2
-
Corrugated wire as counter bearing
Because of the mechanical lever operation, the variable counter bearing and the optimum controlled application of power, this external dent removal system allows dents in almost all vehicle body areas to be pulled out.
Depending on the application area and the damage, the fixing options to the panel being worked can be corrugated wire, pulling bits or U-washers which are spot welded into position.
Dent removal using special panel beating levers
This panel beating technique with pressure is mainly used to rectify smaller dents as a result of hail impact, transportation or parking, without the paint being damaged.
1
-
Deflection by a hook arrangement
Small dents are removed from the inside of the body panel by pushing them outwards in a mechanical process using panel beating levers.
Because of the great variety of shapes of these levers, it is possible to use this panel beating technique on almost all areas of the vehicle body.
Heat working of panels
This repair method allows small and mild dents to be rectified without additional panel beating.
During the repair process, a flame is used to selectively warm areas of the panel to relieve the stresses in the metal. This can cause the dented area to return to its correct shape.
NOTE:Before this method is used, for economy reasons you should check whether it is in fact possible to use the undamaged paint pressure techniques to rectify the problem.
This method can only be used when the dent:
- is not too large and sharp edged.
- shows no signs of the material having stretched.
- is in a surface of the body which curves outwards.
- is not in a repair area which is too structurally solid.
Heat-induced material shrinking
Material shrinking, also called settling in, can be performed in a variety of ways depending on the extent of the damage and the access to the repair area.
These repair processes differ depending on the type of heating and subsequent working of the heated surface. They sub-divide into two basic processes:
- Heating using a carbon electrode.
- Heating using the oxy-acetylene torch.
In the carbon electrode process the working is done exclusively by warming. In this case the access to the repair position is only from the outside.
2
-
Spiral shaped heating pattern
If the damage is concentrated in a spot and is in the form of a more rigid raised area, then the carbon electrode must be replaced by a copper electrode. As heat is applied, slightly more pressure is applied to the raised area.
In the method using heating by the oxy-acetylene torch, material shrinking is achieved by a combination of heat and mechanical working of the damaged area.
2
-
Point heating using the oxy-acetylene torch
3
-
Spiral shaped knocking back with dolly
The repair area must always be accessible from both sides, so that the heated area can be properly worked mechanically.
The combination of heating and mechanical working is very effective.
As soon as the warm point is established, hammering is immediately started using the aluminum hammer together with a suitable dolly on the inside of the repair surface, working in spiral movements towards the warm point. This causes material to build up in the center of the warmed area.
Lead loading
Despite good external panel beating techniques, it is not always possible to rectify every surface unevenness. For this reason, application of lead loading is an important part of panel beating.
NOTE:You will find additional important advice on the topic of lead loading in the joining techniques section.
For corrosion protection and adhesion reasons, on body components subject to more demands, such as doors or hoods, it is preferable to apply lead loading rather than stopper.
In addition, lead loading application is suitable for creation of surface contours when the options for panel beating are limited.
Typical application areas:
- Body components with limited or no access from the rear.
- Body components with very narrow cross-section.
- Body components which are particularly exposed or which can move.
- Weld seams of partial repairs.
- Rocker panel areas, wheel arch edges, side panel areas.
- Doors, hood, luggage compartment lid.
- Swage lines and joint areas.
