Use of no-added-formaldehyde (NAUF) particleboard and MDF wood products can sometimes cause discoloring of exotic veneers, according to www.buildinggreen.com. The site has received reports from design teams that have encountered performance issues resulting in delamination and discoloration of veneers applied to Class A fire-resistant NAUF substrate materials.
Producers of the substrate material have reported that many factors can contribute to these issues, including materials and veneer glues used, environmental conditions, surface coatings, temperatures and pressing times. Another panel producer identified exotic veneers such as makore, wenge and English sycamore cut thinner as being affected by these problems. All substrates were identified as being fire resistant panels. One possible remedy is to use a backer or barrier to prevent borate or silica from the fireproofing materials from reaching the veneer.