on June 18 2013
Wood is a common feature in many homes. Floors, tables, chairs, cabinets, dressers and more are made from different types of wood including oak, pine and mahogany. It is a beautiful, durable material that is available in a wide range of styles. Its versatility and prevalence are two of the primary reasons why applying a finish is so important. Finishes protect wood from scratches, scrapes, nicks and dents, ensuring that it retains its original brilliance for years to come.
There are two primary types of finish, penetrating and surface. Choosing which one to use will depend largely on what you will be applying it to and how much use a floor or piece of furniture is likely to be subjected to. Keep the following questions in mind as you search for the right finish:
• What purposes does a finish serve?
• What types of penetrating finishes are available?
• What types of surface finishes are available?
• What are the appropriate methods for applying finish?
• What other steps should be taken to enhance wood’s appearance and durability?
Penetrating Finishes, Surface Finishes and Applications
Finishes serve a number of purposes. They seal and protect wood from water damage and stains, provide a tough, durable finish for hardwood floors, bring out the natural beauty in unfinished wood and add gloss and shine to stained furniture. Regardless of whether or not wood has been stained, it should be finished.
Like staining, finishing is a project that requires little more than a can of finish, a brush and some patience. Some finishes dry more quickly than others and some require multiple coats. There is no perfect finish that is ideal for every situation, but there are a number of available finishes that will allow you to find the right fit for the job at hand.
Penetrating finishes infiltrate wood’s pores and penetrate the fibers. They are oil based and the most commonly used types are tung oil and linseed oil. Tung oil is derived from the tung tree and provides a beautiful, natural-looking finish. Linseed oil is pressed from flax seeds and has been used as a finish for hundreds of years. Look for linseed oil that has been boiled, which will allow it to dry more quickly.
Danish oil is a hybrid of oil and varnish that provides a little more durability than typical oil finishes. Penetrating finishes are best when used on decorative finishes and on surfaces that won’t receive a lot of use. Though they may show scratches, signs of wear can be easily fixed by simply reapplying finish over worn spots.
• Penetrating finishes are also known as “air-oxidizing” finishes
• They tend to provide a low sheen and take longer to dry than surface finishes
• Lemon, walnut and soy oils are sometimes used for penetrating finishes
• Linseed oil can take a very long time to dry
• Oil and varnish mixes dry more quickly than other oils
• Lightly burnishing finishes between coats will help the next layer adhere more easily
Surface finishes leave a hard film over the top of a wood surface. Rather than penetrating the wood, it adds an extra layer, creating a buffer between the wood and anything it comes in contact with. That way instead of the wood wearing down or getting nicked, the finish takes the brunt of the damage. Surface finish types include lacquer, shellac, polyurethane, varnish and wax.
are very durable but dry slowly, making them susceptible to dust and dirt. Shellac
is a fast-drying natural resin that may need to be thinned with denatured alcohol prior to application. Polyurethane is amongst the most durable finishes available and is offered in multiple sheens. Water-based surface finishes aren’t as tough as other finishes, but they are easy to apply.
• Surface finishes are a mixture of resins and solvents, sometimes called solvent-releasing finishes
• They are more durable and faster-drying than penetrating finishes
• Lacquer provides a shiny, water-resistant finish
• You may need to filter lacquer prior to application to remove solid particles
How a finish is applied depends in part on what kind of finish it is. Oil-based finishes are easiest to apply with a brush or cloth. In many cases, using a cloth or rag will allow for more precise application. Surface finishes are generally applied with a brush. When applying varnish, it is particularly important to make sure the surface is free of dust and dirt. Some finishes can give off hazardous or noxious fumes, so be sure to work in a well-ventilated area and use a respirator to protect your lungs. If you are applying finish to wood that has been finished in the past, be sure to consult the manufacturer’s specifications to see if the two finishes are compatible.
• After an oil-based finish has set, wipe off any excess with a rag
• The type of finish determines durability more so than the number of coats applied
• Lacquer finishes should be sprayed on to ensure even coverage, since they dry so quickly
• Use gloves to protect your hands while you work
Uses and Benefits
Points to Consider
||• Dries faster than other finishes
• Can be easily removed
• Ideal for furniture
• Works well when multiple layers are applied
|• Gives off noxious fumes when applied
• Can be a fire hazard
• Do not use over old paint or varnish
• Usually sprayed on because it dries so
||• Provides a rich, satin finish
• Ideal for furniture and low-traffic areas
• Easy to apply
• Offers a natural look and feel
• Tung and linseed are the most common
• Makes it easy to cover scratches and nicks
|• Not recommended for high-traffic areas
or locations where surface might be
• Doesn’t resist alcohol or water spills
• Dries more slowly
• Be sure to protect your eyes and use
adequate ventilation during application
||• Provides a highly durable, water-resistant
• Natural appearance
• Available in satin, semigloss and glossy
• Ideal for kitchen cabinets, doors, furniture
|• Not recommended for outdoor use
• May yellow or crack when exposed to
sunlight unless UV light absorbers are
• Can be difficult to repair if damaged
||• Provides a hard finish that dries quickly
• May be used as a sealer and stain killer on
drywall, cured plaster and new wood
• Available in multiple colors
• Ideal for furniture and floors
|• Not recommended for wood that will be
exposed to moisture
• Use denatured alcohol to thin and clean
• May break down over time
||• Available in different sheens
• Ideal for use on doors and marine finishes
• Can be used on bare or stained wood
• Very durable
|• Must be applied to a clean, dust-free
surface with a clean brush
• May cause damage to wet surfaces
• Use paint thinner for thinning and
||• Dries quickly
• Does not yellow with age
• Can be used on bare, stained or painted
• Ideal for protecting decorative finishes
|• Not as durable as other finishes
• Brush marks may show up on surface
• Use synthetic brushes to apply
||• Offers a glossy sheen
• Easy to remove
|• Not as durable as other finishes
• Needs to be frequently reapplied
Before adding a finish, consider applying a stain. Stains enhance wood’s appearance, add color and emphasize grain contrast. They may add a glossy finish, highlight wood’s natural appearance or make it blend in better with surrounding décor. Finish is applied over the top of stain to protect it. Conditioner:
Prior to applying stain, you may need to use conditioner. Conditioner helps tame wild grain patterns and evens out stain absorbency, preventing blotchy spots. It is particularly useful on soft woods or wood with knots. Brushes:
Brushes are a crucial component in applying some types of finishes. They may be natural, synthetic or foam. Foam brushes are generally inexpensive and will not shed bristles, but they will wear out quickly and may make it tough to apply a coat evenly. Synthetic brushes are best when used with water-based finishes, as water can sometimes cause natural bristles to swell, making it more difficult to apply stain in a uniform manner.
Oil-based finishes, whether penetrating or surface, can be used with virtually any type of brush. Tug on the bristles before you purchase a brush to make sure they don’t come out easily. If they do, they are likely to stick in the finish and mar the surface of wood. Sanding:
In order to get the perfect finish, chances are you will have to do some sanding. Scuff sanding is a process by which coats of finish are sanded to create scratches that allow subsequent coats to achieve a better bond. Once you have sanded down the surface, use tack cloth to pick up dust and debris so they don’t become embedded within the finish.