Decorative painters are the first to admit that sealing the wood isn't always their top priority when working on a project. After all, painting is the fun part, so why not begin with that? But through trial and error, painters have discovered that properly preparing the wood surface before painting -- sanding and ealing -- really does make a big difference.
Why Sealing Makes Sense
Using a wood sealer is essential to the success of any painting project. Not only does a sealer protect the wood from moisture, dirt, and dust, but it also prevents sap, most commonly found in green wood or wood that hasn't been cured long enough, from working its way up through the paint. Sealing also prepares the wood surface for even coverage of the base coat. And, because sealers dry clear, they're ideal when you want to maintain the natural finish of the wood.
Selecting a Sealer
Not all sealers are the same. How you apply the sealer, the amount of drying time required, and the type of finish differ from product to product. We've rounded up several types of sealers that are commonly available in stores that sell crafts and painting supplies. (When choosing a sealer for your projects, always read the label for instructions on how to use and apply the product.)
All-Purpose Sealers: Sometimes called multipurpose sealers or just plain sealers, these products are ideal because they can be used on virtually any hard, paintable surface. Besides wood, they might be used on plaster, papier-mache, metal or tin, and glass. Look for all-purpose sealers like Accent Waterbase Acrylic Sealer, FolkArt Clearcote Acrylic Sealer (from Plaid), and Delta Ceramcoat Waterbased Sealer.
Wood Sealers: These sealers, including DecoArt Americana Wood Sealer, are primarily applied on wood; some can be used on other surfaces as well.
Specialty Sealers: Jo Sonja offers a Tannin Block Sealer for use on wooden surfaces where tannin, oil, or pitch may bleed through paint. It's great for concealing wood knots. J.W. Etc.'s First Step Wood Sealer works smoothly for applying fabric to wood.
Sealers with Stain: These double-duty products, including J.W. Etc.'s White Lightning and Liquitex Acrylic Wood Stains, let you apply both sealer and stain in one step. Although J.W. Etc.'s White Lightning stain is white, it can be combined with any color of acrylic paint, then applied as a sealer.
Liquitex Acrylic Wood Stains are available in a variety of colors and also can be mixed with any Liquitex Concentrated Artist Colors paint.
Sealer/Finishers: Available in either matte or gloss finish, DecoArt's Americana Acrylic Sealer/Finisher does double duty, sealing surfaces prior to painting and also providing a durable finish on painted surfaces.
Tips for Sealing Success
• Depending on the sealer you use, the surface may feel rough when you run your fingers over it.
This means the grain has risen. Sand the entire piece with fine sandpaper, and you'll create a smooth surface -- smoother than the unsealed wood -- that's perfect for painting.
• Always seal the back side of the board you're working on. Sealing both sides prevents warping.
• Seal and base-coat in one step by combining paint with the sealer. Check the sealer label for
• When applying spray sealers, hold the can about 10 inches from the surface, and spray with a
smooth side-to-side motion. For best results, apply one or more light coats instead of one heavy coat.
Ted's Woodworking - Guide eBook