Iron Tannate Stains

If you have black stains on your wood that no amount  of cleaning by your previous applicators can remove, it is possible that you have iron tannate stains.

Iron tannate stains are the result of a chemical reaction between naturally occurring wood tannates, water, and iron particles.  These iron particles most often are introduced to the wood by roof water runoff, incorrect preparation of the wood using steel wool, or simply through the milling process.

This chemical process of iron tannate staining is not only exacerbated by chlorine bleach but sometimes initiated by it.

Even more disturbing is that this form of staining is not visible until days or even months after stain is applied, and the appearance of these stains can only be removed or minimized after removal of any finishes, as the problem is on the wood itself.

Staining Chemical Stripping