damage and repair
Oxalic Acid — The Wood Stain Lightener
A mild acid used to lighten iron-tannin stains (including some pet-urine blackening) on sanded wood.
Published
What it is
Oxalic acid is the active ingredient in wood deck brighteners. Applied to exposed bare wood after sanding, it can lighten shallow pet-urine tannin stains. It does not work through an existing finish and doesn’t remove deep stains.
Why it matters for your wood floors
This entry is part of our complete glossary covering every term homeowners, realtors, and contractors encounter when dealing with wood floor cleaning, recoating, and refinishing. For full context, see our main guides on recoating, chemical abrasion, and the services we offer.
Need help?
Find a ReCoat Revolution location near you for a free in-home assessment, or read our FAQs for more answers.