April 29, 2013
Maintenance Coats of Finish
The most important thing that you can do to help maintain the finish of your log home is to keep it clean. A washing with Log Wash a couple times a year will help prevent airborne contaminates, dirt, bird droppings and sunlight from degrading the finish. How can keeping the surface clean prevent sunlight from injuring the finish? One of the features of our Advance clear topcoats is that they reflect UV radiation. If the surface is dirty and dull it reflects less sunlight and the absorbed UV light will eventually fade the color and gray the wood. So just like car finishes, the cleaner you keep your home the longer the finish will last. That being said, there will come a time when it may become necessary to do some touch-up work to the topcoat and perhaps the color coat, especially on the south and west walls. The question is, when and where should maintenance coats of finish be applied? The first thing to understand is more is not necessarily better. In other words, if the wall does not need another top coat of stain or topcoat, leave it alone. One of the features of Lifeline finishes is their ability to breathe. This allows water vapor to escape from the wood while preventing liquid water from penetrating through the finish. Technically we call this vapor permeability. If applied at the recommended application rates, two coats of stain and two coats of topcoat maintains enough vapor permeability to allow water that may enter the wood through cracks, checks, and fissures to evaporate through the finish. However, each coat of finish that's applied reduces the vapor permeability of the entire finish system by some percentage. The thicker that a coat is applied, the more it will reduce the vapor permeability. That's one reason why we always recommend applying thin coats. Multiple coats of finish can have the same effect as applying coats that are too thick, they can reduce the vapor permeability to the point where the finish can no longer breathe. The consequence of reducing the ability of a finish to breathe is the risk of the finish peeling if water gets behind it. So although occasional maintenance is an important factor in keeping your finish system in good shape, only apply additional coats where they are needed. So what's the best way to care for your home and extend the life of your finish system? If after a washing with Log Wash you see that the surface has dulled or shows signs if weathering feel free to apply another coat of stain, if needed, and/or Advance topcoat. The dull surface is a sign that the finish has eroded and one or two additional coats will not adversely affect the vapor permeability. But while you are at it you may be tempted to apply another coat of topcoat on those walls that still look good? Additional coats applied to unweathered walls are not necessary and can eventually lead to problems. If applied correctly the film thickness of the unweathered walls is still optimal and the application of additional coats can decrease the vapor permeability to a point where peeling could become an issue. In other words, leave it alone. As opposed to other manufactures' finishes, we do not recommend applying additional coats of stain or topcoat on a yearly schedule. If two coats of stain and two coats of topcoat have already been applied, we recommend applying additional coats only on an "as needed" basis. But we strongly recommend a good cleaning with Log Wash at least once or twice a year to keep your home looking great and add years to the life of your finish.