At one point, your new home was just a dream. Many hours were spent on research and planning. Even more time was devoted to the construction and building process. During the process an exterior finish for the logs or siding was chosen. It was one of the most important decisions to make because of the long-lasting effects it would create.
The exterior finish is the most visible feature of a log or wood sided home. Choosing a finish is not an easy decision to make. Finishing a log home or exterior wood home can be a complex process. Choosing a durable finish with realistic expectations is difficult because vast amounts of conflicting information are available.
According to the October 2000 issue of Consumer Report (CR) on semi-transparent stains, one should be extremely cautious when it comes to selecting an exterior finish. CR states, “the exterior semi-transparent stains tested performed so poorly that CR won’t report on them any longer.” CR exclusively recommends a solid body, opaque stain – period.
A solid body opaque stain? What if you want the character and beauty of the wood to be visible?
Characteristics Of An Exterior Wood Finish
How to Judge the Value of an Exterior Wood Finish:
1) Enhances the beauty and character of the wood rather than covering it up
2) Is easy to re-coat with minimal problems and expense
3) Is durable enough to last a realistic yet reasonable length of time (3 to 5 years vertical surface, 1 to 2 years for horizontal surfaces)
Should the wood look like this?
It won’t if you use a solid body
stain as recommended by Consumer Reports.
The Key to the successful selection of an exterior finish is:
ALL Products Fail.
It is HOW they fail over time
that makes the difference between
a Good Finish and a Bad Finish.
How to Gauge / Compare Exterior Finishes
Ask yourself, “How will this product eventually fail?” If the answer does not meet the three characteristics previously listed, move on. Find the product that provides you the desired results that you need.
No wood finish will last forever. But, if a selection is based on hype and misinformation, restoration will be required very soon. Restoration is expensive and can be avoided if the choice is based on the characteristics listed for selecting an exterior finish.
There are a variety of finishes available on the market. That variety can make the selection process even more difficult. As a side note you should be aware that 95% of the products available have mineral spirits or some other type of solvent in them. Acrylic and water-borne finishes also contains solvents. A reasonable amount of solvent is necessary to obtain the finish characteristics desired. When selecting an exterior wood finish, ask yourself: How will this finish look over the years, especially after three or four coats of application? Then ask: How will this product fail? Have an idea of the right answers before asking product representatives. Then see if they give you a straight answer.
Acrylic-based Finishes: Similar to paint in that it sits on surface of the wood. How does it eventually fail? Peeling is a major indicator of failure. What has to be done when it peels? All of it has to come off and then be reapplied.
Varnishes: What is the indicator of failure? Peeling, the same as acrylic-based.
Oil Emulsions: These finishes are made of oils such as linseed or tung oil dispersed in water, mineral spirit and co-solvents. The water evaporates and the oils soak into the wood. These products eventually fail by oxidizing or becoming chalky. When the finish oxidizes, the surface should first be washed to remove the chalkiness then re-application of the product can be done relatively easily.
Penetrating Oil-Based Finishes: This particular finish is the most common product on the market. It is composed of a combination of drying oils, such as linseed oil, and solvent. Some products contain a blend of oils and resins to enhance durability. These finishes penetrate the deepest into the wood to give the wood a finish from the inside out. Eventually, the finish also fails from oxidization and becomes chalky. By rinsing and re-coating, the wood can be maintained and renewed, like oiling wood furniture. One of the differences between oil emulsions and penetrating oil finishes is that the penetrating finish absorbs into the wood much deeper, especially if the finish is brushed in.
Remember to choose an exterior finish that:
1) Does not cover up the wood,
2) Weathers in a way that is easy to maintain,
3) Lasts three to five years between recoats,
and you will have chosen a good exterior wood finish regardless of what CR said.
Caution: Any finish can be applied incorrectly and become a “Bad” finish. Always follow the directions on the label when using any finish.
After the exterior wood is properly cleaned, brightened, rinsed and has been allowed to dry, the surface is ready for finishing. Even new wood should be cleaned before coating. Remember, this is the first coat of finish the wood will receive. If you are doing it yourself, be sure to follow directions on the product label. If a contractor is hired to complete the job, it is important to verify that the contractor follows the directions as stated on the product label.
Setting Up To Apply The Finish
“Do Not Apply In Direct Sunlight.” Many contractors will argue with this statement. Generally, contractors do not like to being told how to do their job. It will be like talking to a brick wall most of the time. (Note: I have been a painting and wood-finishing contractor since 1983. I know how they can be.)
Applying a finish to a surface that is not in direct sunlight gives the finish a chance to “bite” into the wood. If the surface is hot and dry, the solvents in the finish will quickly evaporate. The solvents help the finish “grip” the surface. There will be many problems ahead if the finish is not able to grip or bond. To avoid potential problems, do not work in direct sunlight. It is easier on both the finish and the finisher. It is necessary to plan the day accordingly. It is best to start on the south side early and be done on that side by 10:30 a.m. Proceed to the west side then move to the north and finish on the east side. As a suggestion, have the south side masked the night before to be ready for an early morning start.
Many finishes can be sprayed. It is more time efficient to spray. However, spraying is not enough. It is essential to back brush the product into the wood. The finish can be sprayed onto the wood surface with a pump up sprayer or, an airless sprayer. Finish the job by back brushing the finish into the wood.
Penetrating oil finishes are the easiest to work with when it comes to brushing. Some of the emulsified oils and water-borne finishes are more complicated to work with. These products tend to dry more quickly and are difficult to back brush. Brush these finishes a lot to prevent lap marks and inconsistencies in the over-all appearance.
When hiring a contractor, it is always a good idea for you and them to be familiar with the procedures and directions stated on the product label. Never assume that a painting or general contractor will know the proper procedures and will follow them according to the directions. Trust and verify. It is the best assurance that your dream home will come out like a dream and not a nightmare.
Typically, one wet-on-wet application is sufficient for the first coat. The wood will “season” and change dramatically over the course of the first 12-18 months. Do not build up a triple coat of finish on the first application to any new wood. Building multiple coats of finish on new wood may result in peeling and a difficult and expensive restoration may be required.
Let’s Do It – The Process
The first step is to mask windows, move cars, protect landscaping, stone, rock, plants and hide the cat and dog. Overspray goes everywhere especially where you don’t want it to, so be prepared for it.
Set the airless sprayer at the lowest pressure possible to generate a steady, controllable spray pattern. If using a pump jug, move a bit slower and you will not have as much overspray. Be sure to wear a respirator, a long sleeve shirt and other protective clothing when spraying. Lungs and skin will absorb the finish just like the wood. You are not wood and don’t need to be preserved, so protect yourself.
Wet-on-wet is a method that has been used to finish hundreds of log and wood sided homes with penetrating oil finishes. It is best to work a section at a time. Wet the wood by spraying a liberal amount of finish onto a section. Spray from the bottom up. Get the wood wet but don’t brush yet. Depending on the product you are using, apply the second wetting application within 30 minutes. Now brush the finish into the wood.
Repeat the process on each section. Typically, vertical surfaces are done before horizontal surfaces. For example, if you were doing a deck, start with the rail first. Spray a section then go back and do the same section again. After brushing the finish into the wood of the rails, go on and do the deck floor using the same process.
If working with an emulsified oil or acrylic-based product there is not as much time for back brushing as with a penetrating oil finish. Until you become familiar with the process and the way a particular finish works, work in small sections to get used to it. Then do the larger walls.
Once the house is done stand back and look at the job. There should not be any lap marks, drips, runs or blotches. Note: If back brushing is not done, it could result in having to do a restoration job in the future.
Remember, when finishing a new log or wood sided home:
1) Make sure the wood is properly clean, dry, and ready for a finish.
2) Plan the work for finishing to be done out of direct sunlight.
3) Spray, if possible, to increase efficiency.
4) Use a wet-on-wet application method.
5) Always back brush the finish into the wood.
Caution: Remember to always read the product label on the can and the specifications regarding the manufacturer’s recommendations whether you do the job yourself or hire a contractor to the job. Spontaneous combustion is always a concern when using any oil product. Read the label carefully for proper clean up and disposal of rags. Stray rags with oil products on them can start a fire.
When the house looks good, you will be a satisfied and proud homeowner.
No Solid Body Opaque Stains here!!!