Spalting colorants as dyes for wood stabilizers

Spalted wood stabilization through various heat-treated resins has become a popular method for dealing with heavily decayed wood that no longer has enough structure to be usable. Among the most popular resins are the solutions of mixed methacrylated esters, which are often tinted with synthetic colorants to add an artificial colored layer to zone line-spalted wood as well as to stabilize the white-rotted areas. This research found that spalting pigments (technically dyes, but referred to as pigments in biological fields)—extracted from spalted wood—could be used in place of the synthetic colorants, thereby adding additional spalting to the wood without any associated decay (and adding additional spalting while stabilizing the wood with the same type of fungi that decayed it in the first place). Of the three fungi tested, the red pigment from Scytalidium cuboideum had the deepest penetration (complete) of the wood and was color stable after the curing process. While the blue–green pigment from Chlorociboria aeruginosa effectively colored the surface of the wood, it did not appear internally. The yellow pigment from S. ganodermophthorum did not show on the wood. None of the fungal colorants affected the properties of the methacrylation. The results of this study offer an intriguing opportunity to replace synthetic colorants with natural ones, which may be particularly attractive to turners of spalted wood who tend to prize natural color over synthetic.