Treating Blue Stain on Log Cabin Logs

Advice on cleaning air-dried cabin logs to remove blue stain. October 19, 2014

I am looking for the best wood preservative for a southern yellow pine log cabin. The logs and lumber have some blue stain and I would like a stain to hide or blend it in. I am debating on whether or not to have the logs kiln dried. They have been air drying for several months now and are down to about 15% MC inside the log with some checking. Any suggestions or recommendations would be appreciated.

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Forum Responses
(Sawing and Drying Forum)
From Gene Wengert, forum technical advisor:
The blue stain indicates that the wood has dried some already. The blue stain can be removed with TSP (trisodium phosphate) cleaner fairly well. As the wood will be dry enough so that fungi can no longer grow, there is no need to use a preservative. Almost all preservatives would not be safe and also are not approved for log cabin use. So, at this point, dry the log (at least the outer sapwood) ASAP. Then get your scrub brush and go to work. Bleach does not do well and also will remove the grain colors and patterns, as it bleaches more than just the fungi color. Bleach does kill the fungus that is existing now, but will not stop new growth. Borates are much safer, but they leach out with rain and can also bloom a bit on the inside, so you would not like that.

Note that the bottom log should be pressure treated, as the risk of decay and insects is high for this bottom location. To avoid this preservative inside the cabin, make the floor high enough. Good log cabin building books will cover this issue.