How to remove tannin stains on wood

Grey or blackish stains due to tannins can sometimes appear on wood, especially if the material still contains a lot of moisture. What to do in such cases? Lets find out together, but first lets try to understand why this happens.

In addition to the better known cellulose, there are also other compounds that make up wood. Some of these fall into the group of extractives, so called because they can be extracted from the wood of trees that have already been felled, using water or other solvents. In this group we also find tannin: a complex, water-soluble substance found in many plants. 

The function of tannin is to defend the plant from fungal attack and subsequent rot, especially if it is in a very humid environment.
Tannins can mainly be found in chestnut and oak wood, as well as in the bark, leaves and fruit of various wood species.

Unfortunately, wood that has been sawn and processed may show dark stains, such as grey or blackish spots, especially when the material is still quite fresh and unseasoned (and therefore still contains a lot of moisture). The problem of staining can also occur in seasoned wood that still contains significant percentages of tannin and comes into contact with water.

Find out how to get rid of unsightly stains with our tannin stain remover!