I followed this trail of information until it led me to an oil-based penetrating sealer that is designed to look for dry cell structure. The oil-based penetrating sealer attacks the weakest areas of the board by penetrating to the bottom of the crack, into the path of the nails, through the knots, and then into the wood.
It is a wise choice to choose cedar for the pickets. Cedar has a natural oil in the wood, which slows the process of warping, cracking, and splitting. To remove the dirt, mold, and residue from previous sealers, it is necessary to lightly power wash the fence. After we wash the fence with water, it is essential to spray or coat the fence with an osalic wood brightener.