How does one recondition a skanky butcher block? A quick Google search was no help – all references were related to general cleaning or removing bacteria related smells. I needed to remove rancid oil from the wood – hardly the same thing. I came up with the following scale in terms of available cleaning options:
- Defcon 1: warm soapy water
- Defcon 2: kosher salt and lemon halves, white vinegar or hydrogen peroxide and scrub with a green scrubbing pad. These kill bacterial odors but do nothing for removing the rancid oil. Also, the salt really dries out the surface wood, so don’t leave it on for more than 4-5 hours.
- Defcon 3: hydrogen peroxide, baking soda and dish soap paste - draws out the penetrated oil when washed off with hot water
- Defcon 4: orbital sanding of the top - removes light surface oil and stains
- Defcon 5: surface planing to remove 1/8” or more of wood - removes deeply penetrated oils or stains
Start with warm soapy water to remove the surface crud. Proceed directly to Defcon 3. Prepare the baking soda paste as above, dowse the board with hot water (just below boiling, ~ 200 degrees) to soften the oil and open the pores of the wood. Then, apply the paste and work it into the wood with a ordinary dish scrub brush or green scrub pad - not steel wool. Allow it to dry for 30 mins. or so before washing it off with hot water. Do not allow this mixture to sit too long; it really strips the oils and dirt from the wood (not as much as salt though). To maintain the wood's uniform appearance, apply the paste to all surfaces that will be visible because untreated areas will be darker in appearance.
Now the important part, immediately after rinsing scrape the wood with a rigid metal spatula in a squeegee fashion, working from one side of the block to the other. I used an old hamburger spatula ($6 at Cash & Carry). Avoid anything with sharp corners (painter scrapper, putty knife) that might gouge the wood. Turn the spatula upside down (handle toward the board) and use a very low angle when scraping. Don’t be afraid to bear down on it.
As you scrape the wood, push the spatula away from you. Water and oil will come from the wood in front of the scraper. Wipe it away immediately with a paper towel. This is the old, rancid oil. For an end grain butcher block, scrape in one direction, rotate the block 90 degrees and scrape it again. Do not scrape across the grain on an edge grain block. You risk damaging the wood. After scraping, the surface of the wood should appear almost white.
You may need to repeat this process a few times depending on the how much oil has soaked into the wood. Mine took four applications, but the result after only a few hours of work was a brand new looking and smelling butcher block. That sure beats replacing it.
Allow the block to dry for a few days. Then, seal any cracks with wood filler. As a final step before re-applying oil to the bare wood, I used an orbital sander with 220 grit paper to touch up the surface of the wood. I followed the steps on the Boos web site when oiling the wood. I used mineral oil from the drug store followed by Howard’s Butcher Block Conditioner (mineral oil mixed with beeswax) from Home Depot as a final sealing coat.
Hope this was helpful. Now, back to your regularly scheduled program.