How to Remove the Pressure Treated Wood Ink Stamp

Lumber is pressure treated with preservatives to prevent the wood from becoming decayed by fungi, termites or micro-organisms. Building codes often require pressure-treated wood when the wood will come into direct contact or within inches of exposed soil. An American Lumber Standard Committee (ALSC) grade mark and an American Wood-Preservers’ Association (AWPA) stamp are often found on wood to certify its quality. Before painting or staining the wood, any visible stamps must be removed.

Things You'll Need

• Sponge
• Paint thinner
• Baking soda
• Toothbrush
• Sponge
• Rubbing alcohol
• Rag
• Electric hand sander
• Fine-grit sandpaper

Instructions

1. Rub the ink stamp with a sponge dampened with paint thinner. This may be sufficient to remove the ink. If not, proceed to Step 2.

2. Make a paste of 3 tsp. baking soda and 1 tsp. water in a bowl. If too dry, add more water, a small amount at a time. Use an old toothbrush to rub the paste onto the ink stamp. Scrub the stamp well. Allow the paste to stand for about 10 minutes and then dampen a sponge with warm water to wash it away.

3. Spread rubbing alcohol over the affected area using a rag. The alcohol will remove any residue left by the baking soda-water paste. If these steps do not remove the stamp, permanent ink was most likely used. Proceed to Step 4.

4. Use an electric hand sander with fine-grit sandpaper to remove the stamp. Sand in the same direction as the wood grain. Continue sanding until the stamp disappears. If a low spot forms on the wood, sand around it to smooth and even the wood as much as possible.

Tips & Warnings

• Whenever possible, place the stamped side of the lumber facing down or in a spot where the stamp will not be visible on the finished project. It therefore may not be necessary to remove it.

References

• American Deck Maintenance: Questions and Answers

Resources

• McGraw-Hill Yearbook of Science and Technology: Wood Preservation