Timber Framers Guild Forums General General Forum Questions Cleaning up weathered cedar logs

Try oxalic acid, it can be found dissolved in deck cleaners, but can also be purchased as a powder from many local paint retailers.

It is best to wet the whole timber with water first then spray on the oxalic acid solution (a garden sprayer works well if you have a lot to do). Give it 20 min. to work then rinse off with water.