An oxalic acid mixture will do wonders for wood that has been stripped and has that dull, grey and lifeless look. You can use it to bring back the natural color of outdoor decking as well.

Then add one-half cup of the oxalic acid crystals to the water and wait until completely dissolved. Apply Page 2 2 the solution to the deck using a mop or sponge. Do not scrub, but simply coat the wood and let it sit for 20 to 30 minutes. Rinse well with a garden hose.

A good mix for brightening wood is two pounds of oxalic acid per 5 gallon pail. Even better is to mix your acids for better results. Most prepared brighteners use a combination of oxalic, phosphoric, and citric acids. The other acids are gentler on the human body and create different effects on certain woods.

Oxalic is about 10,000 times “stronger” than the acetic acid in vinegar (vinegar is a 5% solution of acetic acid). Photo of common Oxalis sp. Most kids recognize the sour taste of the flower stems, which is due to oxalic acid. Oxalic acid is common in the plant kingdom, because it is repellent to herbivores.