Drying Spalted Alder

To halt the growth of spalting fungus, dry quickly and/or heat above 133°F. December 23, 2014

Question (WOODWEB Member) :
I'm looking for some advice on drying spalted red alder. I have read that alder, being one of the softer hardwoods spalts easily and can go punky very quickly. I'm looking for any advice on preventing further deterioration of the wood. I have a Woodmizer LT15 and will be sawing some of this lumber into one inch boards and some into six and eight inch blocks for turning.

When I sticker the boards should I spray them with some type of fungicide to help stop the process of the wood breaking down or will the air drying be enough? I am in the process of building a small kiln and should have it done in the next few weeks. Would there be a benefit to loading this wood into the kiln and bringing the temp up to 120 degrees or so for a few days to kill the fungus and then continuing with the air drying instead of or in addition to a fungicide?

With regard to the turning blocks, should I do the same? I was going to air dry the blocks for a few weeks and then coat them with Anchorseal in an effort to keep the moisture level consistent and avoid checking. Is this a good idea given the active fungus growing inside? Any advice is appreciated. I'm new to the board but have already found an incredible amount of high quality information and advice. Thanks to everyone who take the time to offer your expertise.

Forum Responses
(Sawing and Drying Forum)
From Gene Wengert, forum technical advisor:
Spalting is done by the white rot fungi. They take time, much longer than the month or so of air drying. You will notice a wide variation in color depending on how fast and how hot you dry the wood. With blocks, you can dry the outside fast and get one color and the interior more slowly and get a second color, probably unsuitable to have this color variation. The overall practices and drying procedures are fairly lengthy, so it is hard to give them here. Contact Oregon State University Forest Products Lab for a class and maybe some advice or special training. Or hire a consultant. In general, a kiln is best as you can control the color rather than relying on nature.


From the original questioner:
Gene thank you for such a quick response. Perhaps I wasn't quite clear in my post. The alder I have is already spalted. I am looking for ways to stop the process so that the wood doesn't deteriorate to the point it isn't useable. I know that kiln drying would do this but thought the wood needs to air dry for a period of time before it would go into the kiln. Still, you offered excellent advice and I'll check out Oregon State Univ - thanks.

From Contributor B:

I've had a lot of western red alder, just sliced up about 600 bf this weekend. It spalts like mad, I've seen it go from black-lined to garbage in a summer, though it wasn't well cared for. It could be solid, pretty sap wood in one place, and paper 6" away. Considering the time of year you could likely get away with air drying provided you do all the standard preventative measures, but getting it in the kiln and dry would be best. Sticker stained quickly, but didn't react to contact with steel. So long as enough moisture is present the spalting will advance, so I would recommend either immediately selling the blocks or roughing them out yourself before you try to store them. I'd be mighty surprised if they didn't split out if left whole and stored.

From Contributor Y:
Would spraying or brushing on a fungicide halt the spalting and allow air drying if it can't get into a kiln right away?

From Contributor B:
I've used a borate based product with good results on big leaf maple, but have not tried it on alder.

From Gene Wengert, forum technical advisor:
The use of food poisons, including borates to stop existing fungal activity is not too successful, as the chemical has to get deep into the wood by diffusion. You could heat the wood to 133 F and that will kill all fungi. Or you can remove the moisture that these fungi need to be active - go under 25% MC. As splaying takes time, you can use drying that takes a few weeks to achieve the required MC.

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