To understand the way how the additionally applied wax sticks to the ski base, we need to go a bit deeper into the topic…
Here we do not distinguish between chemical bonds and mechanical retention in general as we did in the part I., but we concentrate on the position of the wax in or on the ski base.
If we speak about how wax sticks to sintered UHMWPE ski base types, we need to distinguish between 1. wax penetration into the inside structure in the ski base and 2. wax adhesion to the ski base surface.
1. wax penetration into the inside structure in the ski base
If you take a piece of a new ski base strip coming directly out of production, weight it and wax it as a usual ski base (apply wax, iron, let cool down, scrap and brush excess wax) and weight it again, you will find out, the piece of ski base strip increased in weight. The weight increase will depend on the type of ski base and the amount of additives incorporated, but it will normally range between 0,6 to 3,0 mg/cm2
This wax penetrated into the ski base does not take part directly in gliding features of the ski base, it improves the gliding features indirectly only: a. it helps the wax layers on the surface to be fixed on the ski base, 2. it can restore worn wax layers on the surface under special conditions, 3. it improves general conditions of the ski base.
2. wax adhesion to the ski base surface
On the very surface of the ski base the wax layers retain partly mechanically in fine microscopic imperfections which are filled with wax, partly with help of chemical bonds. This very top surface is the main snow – ski base interface until it wears. To increase the life time of the very top layers, ski base surface is structured which means: 1. it total surface is increased significantly, 2. surface receives a height profiles with different shapes. Especially the height profile and increased total surface promote the wax layer life time on the very top surface.
Conclusion
Wax penetration helps 1. to fix the top layers in the ski base / snow interface which decides about gliding features, 2. to prolong some gliding features after the top layer has worn off.
Wax adhesion to the very top base surface is responsible for 1. the real interface between ski base / snow interface which decides about gliding features, 2. enables a short life time of top layers only.