Spalting
Spalting is the discoloration and patterning in wood caused by fungal colonization, producing dramatic zone lines, bleaching, and color changes. It occurs in the early stages of decay and is prized by woodworkers for its striking visual effects. The wood must be dried or stabilized before the fungi compromise its structural integrity.
In-Depth Explanation
Spalting occurs when multiple competing fungi colonize a piece of wood simultaneously. The dark zone lines — the most sought-after spalting feature — form at the boundaries where different fungal colonies meet and create melanin barriers to defend their territory. White rot fungi bleach the wood by breaking down lignin, creating lighter areas, while other fungi produce vivid pigments in greens, pinks, and oranges. The key challenge with spalted wood is timing: the wood must be harvested and dried after enough spalting has developed to be visually interesting but before the fungi have weakened the wood to the point of being unusable. Spalted maple is the most commercially popular, with highly spalted turning blanks and figured boards commanding premium prices. Woodworkers often stabilize punky spalted wood with thin cyanoacrylate glue or epoxy resin to make it machinable.
Usage Example
The turner found a perfectly spalted maple log behind the sawmill with dramatic black zone lines throughout, ideal for a series of decorative bowls.