SPALTEN: is the German verb meaning to decompose. It has two major
subdivisions: (1) Schwartzen: meaning to blacken; (2) Bleichen: meaning to whiten. From the
latter we get our word bleach.
Xylaria polymorphia is the fungus responsible for the black lines in the rot (zonelines).
Trametes versicolor causes the bleaching (Bleichen) in the rot.
Chloraciboria aerugenacens causes green coloring in the rot. _
Ceratocystis spp. are known as the pigment fungi causing pink, green, orange and
C. veriscans causes the dark green pigmentation.
Hypocryphalus magnifera is the Scolytid beetle that carries with it the fungi which cause
streaked patterns of vascular discoloration (zone lines) in wood. These are the major fungi
responsible for white rot, pigmentation, and zone lines in rotting wood.
White rot (Bleichen) occurs when the fungus enzymes degrade the lignin in the
wood. When the lignin is gone the support structure of the wood is destroyed. This is what
causes the main problem when turning spalted wood.
Pigments released by the secondary colonizing fungi diffuse through the wood and
do not bind to the cellular structures. The diffusion process is independent of the fungus. Blue
pigment fungi are the most common. The fungus infected beetles that attack box elder are
associated with pink and red pigmentation of the wood. It is the fungus hyphae that releases
Zone lines (pseudosclerotial plate formation - Schwartzen) associated with white
rot destroys strength of the wood. These lines are black. red and sometimes brown.
When two or more fungi antagonize each other one or more of them construct
defense lines consisting of hard, dark mycelium.
Spalting requires an average temperature above 50F (20 to 40 C); ambient"
humidity of 75% or above; wood humidity of at least 20% (spalting ceases with
decreased temperature and humidity below 20%); an appropriate substrate (PALE
hardwoods such as maple, birch, beech, ash, etc. Aspen is too soft); decreased
light; ambient oxygen/carbon dioxide exchange; appropriate fungi; and TIME.
Fungi attacking the Oaks (Quercus) do not easily form zone lines. Fungi causing
white rot destroys much of the wood before any great depth of zone lines can be
Artificial spalting (do it yourself stuff) MUST include all of the above essential factors. It is not
known whether any additives such as manure, beer, etc enhances the process.
Brown rot is caused by fungi that feed on cellulose and carbohydrates in the wood.
White rot is caused by fungi that feed on cellulose and lignin.
Soft rot is caused by fungi that feed on cellulose in very wet conditions.
Heart rot is caused by fungi that feed on the very wet, interior parts of live trees (Piss elm,
hackberry, red oak).
Pocket rot may occur at sites of injured wood (broken limbs, limbs sawed near the trunk) and
is surrounded by sound wood.
Incipient rot is that stage of rot where pigmentation and zone lines are most
desirable for the wood worker.
- The wood worker who wants to stabilize 'his/her spalted wood may use CA glue,
polyester, epoxy resin, polycryl, Wood Hardener, Wood Petrifier, EImers Rotted
Wood Stabilizer, Deft Clear Lacquer, or any other chemical that. Suites his/her
fancy. Depending on techniques, penetration varies. Methyl alcohol thinned Wipe
On Varnish can be centrifuged completely through quarter inch thick walls of
incipient rotted wood to stabilize the wood. All of these materials are best for
surface treatment of the wood.
Or, the woodworker can try vacuum saturation of small blocks of wood. Deep,
through and through stabilization requires special chemicals and techniques which is best
done by professionals (Wood Stabilization Specialists Ine).
The fungi responsible for spalting are not pathogenic for humans but can cause
allergies just as the wood dust can. Those fungi causing respiratory infections are
actinomycetes, aspergilla, blastomycetes, candida, cryptococci, nocardia,
Rhizopus, Rhizomucor, and Cunninghamella. Farmer's lung is due to inhalation
of spores of thermophilic Actinomyces (MicropolysporaJaeni).
More information about turning spaltedswood is available on the StateLine Wood
Turners WEB site.