Q: I am refinishing an old piano that is covered with a mix of old varnish or shellac, a stain and some lighter-colored raw wood. There is also some raised pattern decoration. It’s not worth spending a huge amount of time and effort to fix. My goal is to make the wood a consistent color with a uniform satin finish. Recommendations?
A: You probably don’t want to hear this, but the right way is to refinish it. Find the intersection of the amount of effort you want to expend and the look you are willing to tolerate — from living with it exactly as is, up to doing it right. I’d say the middle ground is cleaning and degreasing the piano, lightly abrading the finish, sealing the existing finish with dewaxed shellac or Zinsser SealCoat and blending the color variations.
You can add color selectively to only some areas of already finished wood either by using glaze (a specialized thickened type of stain designed to go in between layers of clear finish) or toner — another name for tinted finish. Both are available locally: toner will usually be called something like “one-step stain and polyurethane.” Toners are also sold in aerosol cans, usually in much more concentrated colors, by many woodworking specialty stores. Whatever means you use to add color, plan on topping it with another coat of SealCoat afterwards and perhaps one or more coats of clear finish atop that if you feel it needs more depth or protection.