Pink Stain in White Ash

Pink fungal staining is tough to bleach out, and may be allergenic. March 9, 2010

Question
Does anyone have experience removing pink stain in solid white ash lumber? I'm not sure but I would guess that it is a fungal stain (it is not sticker stain). We cut the wood at a sawmill and the stain was visible immediately. The wood has now been air and kiln dried and the stain persists.

Forum Responses
(Finishing Forum)
From contributor R:
You might try a wood bleach on the offensive areas or even a thinned out Clorox laundry bleach might work. Carefully apply the bleach with a Q-Tip and keep an eye on the bleaches reaction. If the pink stain is superficial it won’t take the bleach (either of them) but a few minutes to work. If you use a wood bleach for this job, see if you can’t find the A-B Bleach made by Wood-Kote. It used to be called Speedeway but they since sold to Wood-Kote. The beauty about this bleach is that it won’t leave a foamy mess like some of the other A-B bleaches do. If the stain you’re objecting to was on maple, it would be identified as spalted maple and it’s actually quite prized for some applications.

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From Gene Wengert, forum technical advisor:
Indeed, there is a fungus (we could also accurately call it rot or decay, or call it heart rot or incipient decay) that gets into the living tree (I believe it is in the Phellinus genus) that is pink in color. It will be rather diffuse throughout the heartwood. It is most common near the site of an injury, so would be in the butt log most often. It is quite difficult to bleach the fungi color away as the color is throughout. If the bleach is too strong, the grain will also disappear. The bleach also needs to be neutralized which is not easy to do.

The fungus is dead after drying above 130 F. It might be best if this discolored wood was considered to be enhanced character and then sold at a higher price (similar to wormy chestnut and spalted wood). It is possible that the sanding dust will be an allergen (severe) to some people, so be very careful.