Never hammer a low spot without a dolly behind it. Rule 2: High spots get hammered down directly; lows get pulled or tapped from behind. Rule 3: If you hear a “tick” instead of a “thud,” you’re stretching metal. Rule 4: A crowned panel should rock on a flat surface — if not, find the hidden high spot. Rule 5: Finish with a whacker (soft face hammer) and spoon to smooth ripples.
: Striking the metal directly against a dolly (acting as an anvil) to flatten small, concentrated high spots. Never hammer a low spot without a dolly behind it