Body filler is one of the most valuable materials used in panel beating, helping technicians restore the shape and smoothness of damaged panels before primer and paint are applied. However, improper use can result in visible defects, paint reactions and expensive rework.
According to Ronald Janki of Omnia Panelbeaters, there are five common body filler mistakes that can compromise the quality of a repair.
1. Using Too Much Hardener
Adding extra hardener may seem like a quick way to speed up drying times, but it can create long-term problems. An over-hardened filler mixture can react with the paint system, bleed through after painting and leave visible marks on the finished surface.
2. Using the Wrong Sanding Paper
Even when filler has been mixed and applied correctly, using the wrong sanding paper can cause issues. Coarse or inappropriate abrasives can leave deep scratch patterns that may only become visible after primer has dried. This effect, known as sinkage, can reveal imperfections beneath the paint surface.
3. Applying Filler to an Unprepared Surface
Body filler must be applied to a properly prepared and keyed surface. Applying filler over glossy paint or poorly prepared areas prevents proper adhesion, increasing the risk of bubbling, paint reactions and eventual flaking as the filler separates from the panel.
4. Poor Grinding Preparation
Before filler is applied, the panel and especially the edges of the ground area should be properly levelled. If uneven grinding marks are not addressed, technicians may attempt to hide them with filler. Once the repair is completed, the outlines of those grinding marks can remain visible through the finished paintwork.
5. Neglecting Dust Control
Dust management is often overlooked during the repair process. After sanding the filler to shape, all dust should be thoroughly removed from the repair area. Dust trapped in small holes, seams or crevices can lead to paint reactions, bubbling and flaking after primer and paint have been applied.
These common mistakes highlight the importance of careful preparation, accurate mixing and proper finishing techniques. In panel beating, the quality of the final paint finish depends heavily on the work completed long before the spray gun is used.
Omnia Panelbeaters are located at 127 Terrace Road, Sebenza, Edenvale, and can be contacted on 011 609 0695.
See Omnia Panelbeaters' videos of these mistakes here:
