Panel Beating, Dent Removal and Body Repair Techniques
Panel Beating, Dent Removal and Body Repair Techniques
This domain tests metal finishing: hammer and dolly work, shrinking, filing, filler application and paint preparation. The exam looks for a sequence that restores shape without overstretching or trapping defects.
Core rules
- Use a hammer and dolly to move metal back into shape. On-dolly blows stretch and flatten; off-dolly blows raise a low area. A slapping file shows high spots.
- A pick hammer and shrinking hammer can raise lows and tighten stretched metal. Heat shrinking requires controlled heat and a quench, and must not be overused.
- Work from the outside in, using a guide coat or file to reveal highs and lows.
- Body filler is for minor imperfections, not for filling rust or structural damage. Apply over clean, abraded metal or approved primer.
- Sand with a block and appropriate grit; feathered edges prevent visible rings. Finish with primer before paint.
Worked example
A door has a shallow dent with stretched metal. Reasoning: strip the area, use a hammer and dolly to restore contour, file-check high spots, shrink only if the metal is stretched, then apply a thin filler coat and block-sand. Heavy filler over an unrepaired crown would crack and show under paint.
Traps
Filling over rust; over-shrinking and creating a low; sanding through edges; using a DA on a crowned panel; applying filler too thick.
Key points
On-dolly and off-dolly blows have different shaping effects. A slapping file reveals high spots. Heat shrinking must be controlled and limited. Filler is for minor imperfections, not rust or structure. Block-sand and feather edges before priming.