Wood is often treated with chemical preservatives to extend its life. Unfortunately, you may not want to use wood treated with these chemicals when building something like a doghouse or a tree house for your kids. Borax, also known as sodium borate and sodium tetraborate, is an all-natural product you can use instead. Borax will even protect the wood from becoming infested with insects or from wood decaying fungi.
Prepare your workspace area by laying down a large tarp or plastic tablecloth. You should be making and using your borax wood preservative outdoors.
Measure out 295ml. of borax and 177ml. of boric acid and place them inside a pump sprayer.
Pour 1 quart of hot water over the borax and boric acid powders. Stir until the powder dissolves in the hot water.
Add more hot water until the water level reaches 1 gallon in your pump sprayer. Mix again until completely combined.
Spray the wood with your homemade borax wood preservative. One gallon of this solution will cover 200 square feet of surface area.
Use up all of your borax wood preservative. You will need to make a fresh batch each time you plan on treating your wood.
Borax is toxic to plants. Do not prepare and apply the borax near any flower or vegetable gardens.