How to Finish New Wood Carsiding. Finishing the wood on your carsiding is important not only to the look of the room and carsiding, but also to the texture, color and life of the wood. Some woods--like pine--yellow due to light exposure. Finishing the wood will seal it and keep it from distorting.
Decide the texture and color you desire. If the carsiding you used has the color and texture you want, then a simple clear polyurethane will work. Buy enough to do a couple of coats and a sealant coat. Want a different color? Find a varnish that you desire and use it instead.
Seal the wood with a wash coat first. This can be purchased at the same place you buy your poly, or you can mix it yourself by mixing 20 to 30 percent varnish or poly to paint thinner. Apply evenly and allow to dry. This will not only seal the wood a little better, it will keep the poly from soaking into the wood, making your job easier. It also allows for a more uniform coating.
Use the poly to finish the wood carside by applying it in small sections and wiping it off. Repeat this process over and over until you have reached the desired color and texture.
Watch carefully as you go through the process to make sure you are applying the poly or varnish evenly. This could be a little challenging but is necessary to have one consistent color and texture across the entire wall. Allow it to dry completely before deciding if it needs done again.