Small droplets of molten or hot metal expelled during welding that strike and bond to, pit, or thermally damage glass.
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Meaning and boundaries
Weld spatter is not the same as welding slag. Slag is a flux-derived layer or residue associated with certain welding processes, while spatter consists of ejected metal droplets.
Why it matters in glass restoration
Embedded metal and local thermal damage can create pits, cracks, stress concentrators, or irreversible strength reduction, so removal is not purely cosmetic.