How to Remove Black Rust Stains from Wood Countertops


TL;DR: Bar Keepers Friend is my new best friend. It magically removed stubborn black rust stains from a wood butcher block countertop, with minimal effort. 🧚‍♂✨

After taking a large cast iron pan off a wood butcher block countertop, I was horrified to find what appeared to be burn marks, which they couldn't be as the pan wasn't hot. I scrubbed viciously with various cleaners, to no avail. I really didn't want to have to sand it down, either. Enter: my other best friend, Google. I learned the iron oxide in the pan interacts with the tannins in the wood to create the black stains, but that oxalic acid is equally effective at removing those black iron stains, without damaging the wood. #BLESSED #CHEMISTRY 🙏🧪

How to make the magic happen:
  • STEP 1: Get a cleaner with oxalic acid. I used Bar Keepers Friend.
  • STEP 2: Mix the Bar Keepers Friend powder with enough water to make a spreadable paste.
  • STEP 3: Spread the paste directly onto the stained areas with toothbrush.
  • STEP 4: Let dry for 10-15 minutes; wipe off with damp towel.
  • STEP 6: Repeat, as needed. You might notice the previously-stained areas become lighter than the rest of the wood. In that case, apply the paste more broadly around the previously-stained areas to blend the lightness.
  • STEP 7: Once you are satisfied with the extent of the stain removal, you can apply one or more coats of mineral oil for countertops to help blend and darken the lightened bits of wood.
  • STEP 8: Enjoy the relief of not having had to sand the damn thing. 😅