A Primer on the Uses of Different Paints and Stains

With new colors available in stains, you may wonder which is best for siding and decks--paint or stain?

Visit the paint store nowadays, and you’ll find stains aren’t what they used to be, explains Remodeling Ideas magazine. Paint manufacturers carry stains that come in colors similar to house paint. While it’s tempting to take home rich blue or mahogany stains to brush onto your siding, you need to know whether they’re a match with your wood. If not, you could end up back at the paint store next year.

Here are some suggestions:

* Paint pointers. As a general rule, smooth lumber, such as redwood or cedar, holds paint best, says William Feist, wood finishing researcher with the U.S. Department of Agriculture Forest Products Laboratory in Madison, Wis.

For the longest-lasting paint job, he recommends applying two coats of acrylic latex paint over a stain-blocking acrylic latex primer. An oil-base primer also can be used. The primer seals the wood so it won’t bleed through the top coat of paint. When shopping for paint, it doesn’t pay to cut corners. The cheaper paints contain fewer solids (pigments and binders). That means you’ll have to apply more or heavier coats than you would with better quality paints.

* Semitransparent stains. The only true stains are the oil-base semitransparent stains that penetrate the wood and don’t form a surface film like paint. Semitransparent stains don’t hide the wood grain and won’t blister or peel, even if moisture penetrates the wood. They also protect wood from sunlight damage. Use semitransparent stains for a natural look on rough lumber and plywood (but not smooth plywood). All stains work best on rough-sawed woods. If you want a natural look, put the rough-sawed side of the lumber on the exterior.

* Solid-color stains. Opaque, solid-color stains obscure the natural wood color and grain of siding, but the surface texture of the wood shows through. Feist suggests using the solid-color stains on rough-sawed wood and plywood. But, if you’re looking for a stain that penetrates the wood and doesn’t leave a surface film, don’t use this product.

“The solid-color stains are more like thinned paints than stain,” Feist explains. “They form a film and can peel, flake and do everything else that can go wrong with paints.” Oil-base, solid-color stains are especially ineffective on smooth siding, such as cedar, Feist says.

Before applying, lightly sand the mill glaze on smooth siding and rinse. For the longest life, apply two coats.

* Water-repellent preservatives. Use a water-repellent preservative as a natural finish or as a treatment for bare wood before priming and painting or in areas where old paint has peeled, exposing bare wood. The preservatives don’t contain coloring pigments, but they will darken the color of the wood when used as a natural finish. The first application of the preservative will last only one or two years on smooth surfaces and up to three on rough-sawed surfaces.

* Stains for decks and porches. Don’t forget your deck takes special care, too, because of the abuse the flat surfaces take from the sun, rain, and grinding wear. “The rule for horizontal surfaces is: Don’t apply anything that forms a film,” Feist advises. “Use semitransparent stains or a water-repellent preservative, but never use a solid-color stain on decks because they act more like paints.”