Does a Stain Come Before a Varnish?

Stain Characteristics

• Most wood stains consist of pigments dissolved in a solvent that evaporates as the stain dries, leaving only the pigment. Some oil finishes that harden inside the wood grain to give it a higher degree of protection also contain pigments and can be used as stains. This is true of many types of exterior stains designed to provide the same degree of protection as a conventional wood finish. All stains must penetrate to be effective, however. Any stain that remains on the surface and hides the grain is more properly considered a type of paint.

Varnish Characteristics

• Before polyurethane became the finish of choice for home woodworking products, the term "varnish" usually referred to a finish that consisted of some type of tree resin dissolved in turpentine or mineral spirits. Whether you use a polyurethane varnish or a traditional one, however, you are applying a product meant to be a surface coating. Unlike lacquer or shellac, you can't soften varnish once it has hardened, and it remains a permanent part of the wood surface until it wears off or you sand it off. It prevents anything, including stain, from penetrating the wood.

Finishing Wood

• The proper procedure for finishing wood is to apply any stain you want to use before varnishing it. Sanding is usually a precursor to staining, because it opens the grain of the wood and allows the stain to penetrate more evenly. Some wood species accept stain unevenly, and can benefit from an application of wood conditioner before staining. Once the stain has fully dried, which means the solvent has evaporated and the pigment has bonded, one to several coats of varnish provide a surface coating that prevents the stain from fading and protects the wood.

Glazing

• It is possible to color the wood and apply a surface coating at the same time. The process is called glazing, and you do it by dissolving pigments in the varnish you're going to use. Glazing is not the same as staining, because if the varnish chips off, the color will come with it, but you can use it to create color differences more subtle than possible by staining. You can create interesting color effects by staining the wood with a wood-tone pigment, or leaving it unstained and using primary colors like red or green in your glaze.