What is the primary purpose of a wood aircraft finish?

The primary purpose of a wood aircraft finish is to prevent moisture entry. Wood is a hygroscopic material, meaning it can absorb moisture from the environment, which can lead to issues such as warping, swelling, decay, or even structural failure over time. A properly applied finish creates a barrier that protects the wood from water and moisture, ensuring its longevity and maintaining the integrity of the aircraft structure. This protective layer also contributes to the overall durability of wooden components in aviation applications, making it essential for safe and reliable performance in various environmental conditions. While the aesthetic appeal is certainly important, the crucial function of preventing moisture damage stands out as the primary goal of finishing wood used in aviation.