1. Dish Soap and Brush

Mix a small amount of household bleach with dish soap to create a concentrated cleaning solution, then apply to the stamp area using a brush. Gently scrub in a circular motion, which will gradually fade the stamp, then thoroughly rinse the board with water and let dry.

2. Borax and Brush

Mix Borax with water to form a paste, then apply to the stamp area with a brush with water and let dry.

3. Sandpaper

Using at least an 80-grit sandpaper, meticulously sand the area in the wood’s grain direction until the stamp vanishes. Wipe away any debris and use a finer grit sandpaper for a smoother finish if necessary.

4. Paint Thinner and Steel Wool

Employ paint thinner in accordance with the manufacturer’s instructions, applying it to the stamp and scrubbing the steel wool. However, be cautious, as excessive use of paint thinner may leave the wood susceptible to warping or cracking.

5. Paint and Deck Stripper

Use a paint or deck stripper designed for wood surfaces, but be mindful as it may remove the top layers of the wood along with the stamp's ink. Follow the product’s instructions for the best results.

If none of these methods prove successful in completely removing the mill stamp, apply a stain or color finish to the board. For outdoor projects like decks, be mindful of which side of the board you select as the upward side, as this can affect the appearance and overall quality of the finished project.

Removing mill stamps from lumber boards requires patience and careful consideration of the method you choose. Depending on the condition of the wood and the visibility of the stamp, one of these five methods should help you achieve the desired result and prepare the lumber for your woodworking or construction project.