The crumbling, dry edges of a board indicate that it's infested with a fungal infection commonly known as dry rot. Any wood exposed to moisture is at risk of infection by fungi. To help prevent dry rot in wood, paint it with a preservative, such as a borate solution.
Protect Yourself First
Before mixing any homemade wood preservative, put on shoes, long sleeves and pants, safety goggles and a dust mask. In addition, keep children and pets away from the mixing and application areas, and off the treated wood. Borax and boric acid can severely damage your eyes and lungs, and they cause serious skin irritation.
Homemade Borate Solution
Make a homemade borate preservative by mixing 1½ cups of powdered borax with 1 cup of boric acid. Add the borate mixture to 3 quarts of warm water in a 5-gallon bucket. Mix it thoroughly, until the powder completely dissolves, and then add warm water to make 1 gallon of a 10 percent solution. Then immediately paint the borate solution onto the bare wood, allow it to dry and paint a second coat over the first.
Often Mentioned but Not a Good Idea
While a homemade borate and propylene glycol solution is often mentioned as a wood preservative, the instructions call for boiling the mixture until it reaches 260 degrees Fahrenheit. While borax and boric acid are not flammable, the flash point of propylene glycol is 224.6 degrees Fahrenheit; it may catch fire or explode. The risk of heating propylene glycol is too great to recommend its use as a wood preservative.
- University of Arizona Extension: Managing Wood Decay
- Wood Rot and Dry Rot Homemade Wood Treatments
- United States Department of Agriculture: Comparison of Wood Preservatives in Stake Tests
- National Pesticide Information Center: Boric Acid
- Science Lab.com: Material Safety Data Sheet -- Propylene Glycol MSDS
- Photo Credit leungchopan/iStock/Getty Images
Copper Sulfate Wood Treatment
Manufacturers treat wood for use in construction. There are many different ways they treat wood timbers based on their purposes. The treatment...
DIY Natural Wood Sealant
Sealant is beneficial for any type of wood item, especially for outdoor wood and wood furniture indoors that may come in contact...
How to Use Propylene Glycol to Prevent Wood Dry Rot
Propylene glycol is an odorless, colorless compound often found in stores as an environmentally friendly alternative to antifreeze. The liquid is used...
Homemade Deck Finish
Getting the most out of your deck means keeping the wood in good condition and protecting it from weather. A variety of...
Does Linseed Oil Help Preserve Wood?
Linseed oil, pressed out of the flax seed, is a common outdoor wood preservative. It soaks deep into the wood, protecting it...
Eco-Safe Ways to Seal Raised Beds
Building a raised garden bed creates an interesting dilemma: If you use pressure-treated wood or commercial wood sealers, you risk having unwanted...