When you ask a question such as the one posed in the title, it’s important to start with another question or perhaps to set a goal: What do you want to accomplish when you put any type of finish on wood? If you want a specific color, a tone that defines the piece as much as its shape does, then a good stain will generally achieve that.
But to get preservation of wood, it’s essential to choose the correct stain. This will usually be an oil stain designed for exterior use to get the proper enhancement of the wood grain and also protect the timber itself from attack by moisture, thanks to better penetration into the wood.
You should also talk with your paint and stain professional about using a stain that inhibits the effects of ultra-violet (UV) light rays. This protects the wood from damage caused by exposure to the sun and helps hold the color.
Of course, you always have choices when it comes to finishing wood. You could make color your priority and select from a wide range of paint hues. As you put your favorite color on the wood, you’ll also be taking action that will help preserve the wood, primarily because a good coat of paint stops rain and sunlight from reaching the wood beneath the paint layer.
But if you want to get your cover coat to penetrate as deeply as possible, you’ll probably get better absorption with a stain. Paint, as it ages, will dry, crack, and peel, which not only exposes the wood to the elements but also detracts from appearance. Stain, in comparison, won’t peel or crack, though it will lose color (fade) as time passes. It’s also important to take into account the type of wood you’re finishing. For example, cedar can be used as an exterior wood but it doesn’t work well with paint.
More about Stains
If you decide on what is known as solid-color stain, you’re choosing a product that works on wood as a thin paint would. It’s best to treat this type of stain the same as paint, using a primer coat and two finish coats. Keep in mind that varnish is a top coat and should probably be used with a penetrating stain. The best option, of course, is to choose your stain based on its performance as a penetrating finish. The goal is to fill the pores of the wood surface. You might also want to learn about the mildew-resistance properties of your stain.
You can also choose a semi-transparent oil stain because it is a penetrating finish that generally includes wood preservatives and a water-repellent ingredient. You should also consider the amount and type of pigment giving the stain its color. Pigment is basically tiny particles that help to resist the effects of UV radiation. You could research so deeply you might even look for indication of transoxides, which are small pigments that help UV resistance. If your wood is weathered or rough-sawn, you should use two coats of penetrating stain.