Furniture finishes

So, you finally built up the courage to clean out the garage. Way in the back, you come upon that old bureau that grandma gave you just before she passed away. Under those multiple layers of faded and scratched paint you can just make out sets of ornate handles, lion’s paw legs, barely discernable haut-relief floral designs on the drawers. It comes to you in a flash, a noble thought. “I’ll fix it up and give it to my daughter for her birthday”. You can already imagine her exclamation of surprised admiration as she plants appreciative kisses on both of your cheeks. Naturally, you’ll be modest “It was nothing, a few passes of the sander, a little varnish, you know…”
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Before we begin
Types
Characteristics
So what do you choose?
Waterproofing/water repellence
Ultra violet light
Ease of application
Colour change (yellowing)
Accessories
Glossary

Before we begin

A few items that you should know:
  • The subject “wood finishes” is very broad. So to narrow it down for the purposes of this text, we will be discussing smaller scale, panelling and furniture type finishes, as opposed to larger scale finishes like those designed for wood siding, decks, fences, hardwood floors, etc.
  • A note of warning. If you come across a piece of furniture that still appears to have its original finish, think twice before making any alterations. Refinishing antiques can significantly reduce their value and there are occasional surprises to be found so, when in doubt about the antique value of a piece, consult a recognized expert.
  • Another warning. The fumes from some of the products discussed below, particularly from the oil-based varieties, can be dangerous when breathed in over a period of time. Always work in a well-ventilated area, but if you can’t, there are fairly inexpensive masks specifically designed to protect you from toxic fumes.
  • Always read and heed the manufacturer’s instructions. Furniture finishes can be finicky and more than one novice has had to strip off the new, but flawed, coat and start over.
  • Dust is the enemy of the furniture refinisher. On one hand you’re creating large volumes of the stuff with the planer, the saws, the sander, etc., while on the other, the best way to botch a piece is to have dust settle on the finishing coats while they dry. When at the finishing coat stage, make sure that everything, including the air, is completely dust-free.
  • A glossary of the main terms can be found at the end of this text.

    • Types

    The list of furniture finishes is extensive and there’s something for practically every situation. Overall, finishes can be divided into the following categories:

    Paint

    Viewed in a larger sense, paint is a wood finish, but on the other hand, the purpose of paint is to hide wood surfaces, while the bulk of the products we will be discussing here are designed to enhance wood surfaces by bringing out their natural colours and grain. Due to this, we will leave paint for another day and stick to wood surface enhancing products.

    Stains

    Stains are liquid compounds containing coloured pigments designed to alter wood colour while not completely masking the underlying grain and natural colour. There are two types of oil-based stains, penetrating and non-penetrating. In the first case, the pigments penetrate into the wood as opposed to merely sitting on the surface in the second type. Stains are often coloured to imitate various wood species such as mahogany, maple, teak, etc. Stains can be applied and left as is, or sealed with a transparent coat of varnish, shellac, etc.

    If it is a good quality grain like cherry or hickory, highlight it by using a penetrating stain. If the wood is of a lesser quality, like pine or gum tree, it is better to choose a pigmented stain because it obscures the grain flaws.

    Oils

    While oils are first and foremost employed to protect wood from humidity, an application will also bring out the wood’s natural colour and grain without significantly altering its basic colour. Unfortunately, oils do little to protect wood from dirt and stains, and cleaning oiled surfaces is more difficult that cleaning varnished surfaces. The most common, basic oils used in furniture refinishing and maintenance are linseed oil, tung oil, citrus oil (lemon and orange) and paraffin oil.

    Waxes

    Beeswax and carnuba, used individually or in mixtures, are probably the best-known furniture waxes. However, waxes tend to wear off fairly quickly and must be reapplied often. Repeated use will eventually create a thick, dull layer and, starting with furniture stripper, necessitate a complete overhaul of the piece. Never apply wax directly on unsealed wood.

    Varnish

    It’s important to realize that varnish is not a single formulation, but instead a generic term for compounds that are traditionally made up of a base, oil or water, and a resin. Generally, oil-based varnishes are more durable, although some users maintain that they’re also more difficult to apply successfully and they give off a strong odour while drying.

    Synthetics

    More recently, polyurethane and acrylic have replaced plant resins in formulations that produce hard, durable finishes that have found favour with both individual and professional users alike, but are too often referred to mistakenly as varnishes, despite the manufacturers use of the term “clear finishes”. Synthetics come in all sheens and some products now combine both the stain and the finish in one.

    Shellac

    Many people, who only associate shellac with wood finishing, would be surprised to learn that it’s also used in electronics, fireworks, phonograph records and even as a pill coating. Many serious woodworkers and cabinetmakers swear by shellac and use it exclusively. However, the novice must know that shellac comes first in dry form and must be crushed and combined, in varying proportions, with denatured alcohol to obtain the desired mixture - a science unto itself. There are premixed solutions on the market, but shellac mixtures can degrade over time, hence the tendency towards the dried form. Shellac can also be trickier to apply than synthetic coats and the best way to learn the art is to watch an expert. That said, in the hands of said expert, the results can be stunning. Also remember that shellac is not suitable for kitchen applications, as it’s easily marred by strong detergents, heat, ammonia, etc.

    Lacquer

    Lacquer can truly be called an “ancient” form of preserving finishes on wood, but also on other materials. It’s also very demanding and requires knowledge and experience to get it right, so it’s use is usually well beyond the skill level of the novice. The idea when using lacquer is to build up layer upon layer. This technique adds “depth” to the underlying finish, as well as a measure of protection from humidity and other elements. Lacquer can also be purchased in aerosol cans.
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