Before mixing any type of filler, the area to be filled, whether it be a small dimple or a previously straightened metal panel, must be thoroughly dry and free from wax, grease or dust. Check that the correct type of bodyfiller is being used for the metal surface, if it is galvanised or aluminium. Remove existing paint and primer down to the metal surface over the whole area to be filled, using a powered grinder or sander where possible, to produce a rough surface for the filler to adhere to. Original factory baked finishes can be simply sanded with 80 -120 grit paper if the area to be filled is very small, but best adhesion is gained by stripping to bare metal for repairs larger than 5cm.
When power tools are not available use a coarse grade (40 grit) production paper to achieve the same effect. Close attention must be paid particularly to the outer edges of the repair area where the filler will need to be feathered out. If the surface is not thoroughly roughened it will be impossible to blend the filler properly into the surrounding panel without leaving an edge which will be very visible when the repair is painted. Finish the edges of the coarse sanded area with 120 - 180 grit paper to help prevent deep scratches at the edges of the repair which are easy to miss until the paint is applied.
If creases in the metal prevent the use of abrasives score the surface heavily with a file or screwdriver blade to ensure the bodyfiller adheres firmly to the panel.
Mix the bodyfiller with the correct hardener according to the makers instructions, making sure it is well mixed and totally streak-free, preferably within 2-3mins to allow working time on the panel before it begins to set. Apply firmly to the repair, building up the surface until it is just a little proud of the surrounding panel to allow for sanding. Use two or three thinner applications if needed, rather than one deep layer, which is harder to apply smoothly and may sag before it sets. Sanding is not needed between coats of bodyfiller, but it is advisable to smooth off any spikes or really rough areas to make further applications easier.>>>Continued
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ed to be feathered out. If the surface is not thoroughly roughened it will be impossible to blend the filler properly into the surrounding panel without leaving an edge which will be very visible when the repair is painted. Finish the edges of the coarse sanded area with 120 - 180 grit paper to help prevent deep scratches at the edges of the repair which are easy to miss until the paint is applied.
repair, building up the surface until it is just a little proud of the surrounding panel to allow for sanding. Use two or three thinner applications if needed, rather than one deep layer, which is harder to apply smoothly and may sag before it sets. Sanding is not needed between coats of bodyfiller, but it is advisable to smooth off any spikes or really rough areas to make further applications easier.>>>