It’s crazy how the process of decay can sometimes be beautiful. As you probably know, I’m really interested in hardwoods, and have been collecting them ever since I lived in Carlsbad, CA, and discovered the local store called Tropical Exotic Hardwoods. It was there that I discovered how varied the colors, textures, grain patterns, 
smells…and prices…of hardwoods could be. Soon I discovered the phenomenon of “spalting.”
Spalting: Coloration changes and line patterns in wood caused by fungi.
There are multiple technical types of spalting effects, but in my mind they can be easily simplified for the end woodworker into two categories: shading and zoning. Both types are easily identifiable in this photo of Spalted Tamarind. My sister sent me this block of wood for my birthday, and it is is the most beautiful one I have seen in person. The shading effect of spalting can be seen in the grey areas of the block, as Tamarind is naturally the lighter tan color. Shading isn’t always grey, as can be seen in the top left of the photo, the reddish brown streak is also shading. The shaded areas are where the spalting fungi are growing and developing.
Even more interesting to me is the spalting effect known as zoning, illustrated well in the second photo, below. This block is also Spalted Tamarind (my favorite of the spalted woods I’ve worked with). The black lines which, on the cross cut, look almost like topographical lines on a map, are examples of zoning. These are areas where two types of fungi have, in effect, built a border around their zones, separating and defending their resources.
Spalting does decrease the strength of wood, and can realistically only be preserved in hardwoods, as soft woods rot and crumble under the effects of spalting. Spalting can naturally and purposely induced in wood, and it greatly increases the value of a block of wood if executed well (see articles below). If it is not stopped (by drying the wood to kill the fungi…again see articles below) then it will continue to decompose and weaken the wood. When you have a turning block of spalted wood as shown in my pictures, the spalting had started and then was stopped before too much weakening of the wood had taken place.
Of course, this blog post is a very simplified version of biological processes with the end woodworker in mind. To learn more about spalting from people who are a lot smarter than me, visit the links below.
– http://www.fpl.fs.fed.us/documnts/techline/producing-spalted-wood.pdf
– http://en.wikipedia.org/wiki/Spalting
– http://www.northernspalting.com/beginners-guide/
-Justin Nelson
Owner/Artisan
Fernweh Woodworking
© 2015 Fernweh Woodworking, LLC, All Rights Reserved
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