Wipe down the handrails with a tack cloth or broom to remove dirt and dust, which could ruin the way the sealant bonds with the wood. Do not use water to clean the surface, because water thins and dilutes sealant.
Cover the underlying and surrounding grass, trees and plants with tarp or drop cloths to protect them from sealant. Sealant will stain or kill plants.
Dampen a soft brush or rag with sealant. Wipe onto the handrail. Use a separate rag to wipe away the excess, ensuring a flatter finish. Or use a staining brush to apply the sealant.
Coat the handrail in a single, thin coat of sealant. Allow this coat to dry for an hour (or the time specified by the product’s directions). Apply a second coat.
Inspect your work after the second coat has dried for an hour. Apply another coat or touch-ups if you feel it is necessary or the directions call for it. Let the final coat dry overnight before exposing the handrail to moisture or touching it.