Spalt Your Own Lumber: Introduction
April 13th, 2009 in blogsGreetings! Some of you may remember me from an article in FWW last summer, DIY Spalting (from FWW #199). My inbox has been pinging non-stop since the issue hit the shelves, and I have to admit that I have been overwhelmed with the response. So, I'd like to introduce myself to all of you and continue to share my spalting knowledge with the FWW family.
As you may (not) recall, I'm a PhD student at Michigan Technological University researching spalting. Spalting is when fungi color wood (not when the tree does it alone), and can come in any color you can imagine. My current research focus is on color stimulation, but I've done a lot of preliminary work on the actual spalting process. I actually spalt wood in my bathroom using big plastic tubs and vermiculite as a moisture control. I've spent the past several summers collecting fungi and documenting their color contributions to spalting.

Spalting tub. Robinson inspects the spalting pattern on a sample block.
MORE ON SPALTING
Summer is right around the corner, which means the mushrooms will be peeking up through the duff in a few months. I hope to bring you photos of some of my favorite spalting fungi, along with examples of their work on various wood species. I'd also love to answer any of your spalting questions, and would love to hear about (and see) some of your spalting triumphs (and frustrations)!
For today I'll leave you with a piece of hemlock with my favorite spalting color combination: pink and yellow. Pink stain is most often caused by Arthrographis cuboidea, but that yellow could be any number of fungi. That Athrographis has pretty much taken over one of my tubs, and I keep pulling out piece after piece of pink wood!
Got questions about spalting? Post a comment below.
posted in: blogs
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Comments (16)
The cutoffs you mentioned may be useful, and they may not be. If the cutoffs are still green then there is a good chance that the fungus is still active. If they're dry, you'll need to test them. Get a plastic bin with a lid and stick your pieces inside. Splash some tap water over the surface 2-3 times over the next week. After about 10 days, see if any mycelium is growing on the surface (it should be white. If its green, thats just a surface mold, and completely useless in terms of spalting). If no mycelium grows then your spores are probably not viable anymore. If it does grow, stick it in with some wood you want to spalt, and make sure everything is nice and wet.
Let me know how it goes!
Seri Posted: 9:20 am on May 24th
Also, what about using cutoffs from wood that's already spalted? I recently made a jewelry box with a spalted maple top and I have a lot of shavings and small cutoffs. Are they useful as sources for fungus? Posted: 10:42 am on May 14th
http://www.colostate.edu/programs/cowood/library/Blue-Stain/Blue_Stain_markup.pdf
Basically, the beetles carry the blue stain spores on themselves. When they infect a tree, the spores tag along for the ride, and get free access to the inside of the tree.
As for sealing blue stained wood, you have some decisions to make. Most spalting colors fade under direct sunlight. There are UV protectant finishes available, but most amber the wood. That isn't such a big deal if you're working with cheery, walnut or even maple, but if you're hoping to keep a strong color contrast on your white wood, you'll need to look elsewhere.
Personally, I prefer to use a paste wax for wood that will not be under heavy use, and a water-based polycrylic (many are produced by MinWax) for heavy use applications. Neither amber the wood, and both produced substantially fewer toxic fumes as you apply them. Posted: 9:40 am on April 18th
--is the blue staining "spalding"
--any suggestions for staining, sealing, etc this wood when i make furniture of it. i want to maintain this beautiful color.
thanks Posted: 5:31 pm on April 17th
In general though, the spalting stops when you drop the moisture of the wood below a certain level (air dry is too dry for fungi). The fungus can't be active without water, so it is dormant. Finishing seals the spores into the wood and cuts off air flow to the remaining fungal hyphae (the 'roots' of the fungus), which also stops growth. Properly sealed spalted wood is perfectly safe for normal uses! Posted: 9:52 pm on April 16th
After you've let the wood lie in the dark with the fungus and spalt, you take it out, brush it off, let it dry and plane it... Does the spalting process stop on its own? Is the fungus still active in the wood? Does the finishing process kill off the fungus?
Thanks! Posted: 9:43 pm on April 16th
I cut it into slabs on my bandsaw, and the spalted pattern turned out pretty nice. Now I'll hopefully be able to turn it into some cabinet panels of my own without screwing up... Posted: 8:54 pm on April 16th
Brady Posted: 4:54 pm on April 16th
What type of wood are your shingles made out of?
What color is the fungus?
Does it form a fruiting body (mushroom)?
Unless you actually have the old type of solid wood shingle, I'm betting that what you have is algae, not fungi. Algae don't work for spalting, but they can certainly make your roof look pretty nasty! Posted: 7:27 am on April 15th