Finishes for Handrails
By Vince Palmere
Handrails around your deck or porches should represent an attractiveness of craftsmanship and features of your home. Take a good look when you walk into your house. The craftsmanship of the wood railing often reveals the storyline of quality for the finished carpentry work. Here are a few things to consider regarding finishing your handrails.
As the handrails dry, cracks and fissures will develop on the surface. There is no way to prevent this from occurring. If a finish is applied before these open up, once they do open they provide a path for water to soak into the rail behind the finish. When the sun comes out and the rail heats up, the water turns into vapor which may exert enough pressure to actually push the finish right off the wood. In winter months the water in the wood will freeze and expand and that too can pop the finish off the surface. However if a finish is applied AFTER these cracks and fissures have developed, the finish will get into them during the application process essentially sealing them and preventing any rainwater from soaking into the wood.
We strongly recommend that handrail be allowed to dry to less than 20% moisture content before doing anything to them. This may take two to six months depending on how green they are and the diameter of the rails.
First, let's differentiate between the upper and lower horizontal rails and the vertical posts, spindles and balusters. Once dry, vertical surfaces like posts, etc can be finished just like a log wall. They rarely need to be sanded and one or two coats of pigmented stain as well as Advance Topcoat may be applied to them without a problem.
The horizontal rails are a somewhat different story. Although it may not be absolutely necessary to sand the lower rail it is always a good idea, especially if they are showing signs of splits and fissures. But it's the upper horizontal rail that requires the most attention. Once dry they need to be sanded. You don't want to sand them slick, you need to use 60 to 80 grit sandpaper or a medium sanding pad and just scuff them up a bit. This will remove any cambium or glaze on the surface and give the finish something to hold onto. After sanding, wash them down with Log Wash. It's not necessary to use a pressure washer, just apply the Log Wash with a sprayer, sponge or rag and rinse it off with a garden hose.
When the surface is dry you can apply the finish. We recommend the application of only one coat to start with. If you are using Ultra-1 or Endure, one coat is all that you'll need. In the case of Ultra-2 or Exterior it's better to apply the first coat then wait a few months before applying the second coat. That way the application of the second coat will help seal any cracks and fissures that may appear. Under no circumstances should Advance Gloss or Satin be applied to the top handrails. They can be applied to any vertical posts, spindles or balusters but not the upper or lower horizontal rails.
The main thing when dealing with the top rail is to avoid building up multiple coats of finish. The more coats you apply the more susceptible it becomes to peeling. That's one reason why you should not apply a topcoat to the horizontal rails. Since the top rail takes the most beating from the sun, wind and rain it will probably need some maintenance every year or two. One thing to look for is any large checks that open up. If the width of a split or check exceeds 1/4 inch, it should be sealed with Check Mate 2. That will help prevent large amounts of water from getting into the rail.