Choosing the Best Fence Sealer

Not sure if a fence sealer is needed for your fence?


Natural wood is a beautiful fencing material. Despite advances in technology that provide other options it remains the choice of many.

But to keep it beautiful some treatment is needed. There is a vast range of choices.

The choice of wood itself will help provide some protection. Pressure treated lumber is the common means of providing that first layer of defense. A good sealer, applied within a few months, is the next.

A fence sealer provides protection not only against invading organisms like fungus or insects, but also help warping, cracking or splitting.

Primers or sealers are perhaps the most basic option. They perform that single needed service. Some go a step further and mask imperfections in the wood. All have their value. Any compound that contains a water-repellent preservative is a good choice, since moisture is a major factor in the degradation of wood outdoors.


Types of Fence Sealers

There are three basic types: latex, shellac and alkyd.

Latex can cover marks or black tannic acid stains and provide a base for later treatments.

Shellac forms a hard surface that will endure years of harsh treatment from wind and rain.

Alkyd soaks into the wood and creates a barrier to moisture and fungi that grow in it. Many sealers also have an actual fungicide as part of the mixture.


Tips for Success

A wood sealer used on soft woods will allow for a more even application of stain. For those who like the look of natural wood, and therefore choose a wood-toned (low pigment) stain, it makes for a good choice.

For wood that has been around a while a sealer can only provide limited benefit unless the wood is first treated with something else. That something else is usually a form of oxalic acid, a material that may go by the name of wood cleaner or wood bleach, or even wood brightener. Many deck washes contain oxalic acid.

As wood ages it tends to become gray. That’s true of a wide variety of common species used in fences, such as pine, oak or cedar. Oxalic acid is no miracle cure. But the results do often astound those who have mostly given up on refinishing their fence. It reaches down into the top layers, ‘fluffing’ them up, killing mold and fungus, and making many fences look nearly new and bare.

Many a fence has gained several more years of life from a simple application of this wash. It can be ‘painted’ on with a brush or sprayed on.

Once the fence dries the wood is ready for treatment to keep it looking good. That usually comes down to painting or staining. A fence sealer can help, but they won’t be as useful as they would on new wood since even oxalic-acid washed wood fences that are several years old don’t have the absorbency of new wood.

The choices here usually come down to stain or paint. Wood stains, strictly speaking, don’t protect wood – they merely color it. But many types are combined in the can with compounds that do provide that feature. All paints, whether latex or oil-based, will not only color but by their nature also protect.