Tips on redwood exterior finishes

EEDWOOD has a reputation for flperforming well outdoors without a protective finish, but any wood looks better and lasts longer maintained regularly with a protective coating.

Redwood takes and holds finishes better than other woods. Merchants can establish themselves as redwood specialists by providing customers with up to date information on the proper finishes and application techniques.

Clear water repellents slow the natural weathering of redwood, letting the color soften to a buckskin tan and permitting grain textures to show through. For best results, water repellents should be applied with a brush, letting the wood absorb as much finish as possible without leaving a residue. Because the water repellency usually comes from a waxy substance, such as paraflin, refinishing is required at relatively short intervals (18-24 months).

Story at a Glance

Guide to best finishes for red- wood . product and applF cation tips to use in advising customers . . . waystoinsure customer satisfaction.

Bleaching oils accelerate redwood's natural reaction to sun and moisture, turning driftwood gray. Bleaches should be applied with a brush or roller according to manufacturer's directions. Bleaches are aided by sunlight and moisture, so it helps to dampen surfaces with a fine spray from a garden hose before applying. The gray color is virtually permanent; however the protection provided by the finish only lasts about two years.

Semitransparent stains offer more choices in hue and color saturation. When used on decks and walking surfaces, stains should be specifically formulated for decks, otherwise heavy traflic may wear trails through the coating surface. Semitransparent stains should be applied with a brush. The roller is the second best method. Care should be taken to avoid lap marks which can be pronounced. Semitransparent stains will last three to five years depending on the use and ciimate. They are one of the more durable options.

Opaque stains are heavily pigmented, often giving the appearance of paint and hiding the wood grain. Because they are breathing finishes, they are easier to apply and maintain. Stains should be applied with a brush according to manufacturer's directions. Two coats may be necessary for new wood. Like semitransparent stains, opaque stains will last between three and five years.

Paints are durable and attractive, but require more careful preparation than stains. Paints should only be applied to certified kiln dried redwood. One oil or alkyd resin primecoat and two finish coats are recommended for new wood. Paint can be refinished with one coat after most of the old coat has worn away. Because paint films that are too thick tend to crack and peel, it is best to not repaint too frequently. If it is necessary to remove paint by sanding, heads of galvanized nails must be countersunk to prevent nail stains. Quality paint applied properly can last five to ten years.