Chapter 3: Factors influencing ski waxing: Snow types and temperatures

Understanding these dynamic conditions is central to our approach. Our waxes are meticulously formulated with a deep understanding of various snow types, helping skiers make informed choices. Let us guide you through understanding snow characteristics and the art of wax selection.

Temperature

Reading the air temperature in the shade is the first primary starting point for wax selection. We recommend doing this on several spots along the course. Snow temperature at the surface can also be helpful, but remember that once the temperature reaches freezing (0°C or 32°F), the snow will remain at that temperature regardless of rising air temperature. At this point, it is best to use air temperatures and focus on the proper steps for dealing with the increased water content of the snow.

Humidity

Humidity is important, but more as a local climate trend rather than a need to measure every percentile. It is essential to know if you are waxing skis for a dry climate (average humidity below 50%), a typical climate (50% to 80%), or a high humidity climate (80% to 100%). Beyond this, of course, is adjusting to falling precipitation.

Snow granulation

The appearance of the snow crystal and consequent snow surface is vital for wax selection.

Falling, or fresh new fallen snow, is the most critical for waxing, as the sharp crystals require a wax that will resist snow crystal penetration. At warmer temperatures, they must also have the ability to repel water.

Artificial snow is common in racing situations. Freshly made snow at cold temperatures requires the addition of synthetic paraffin, such as with PS Polar, PS05, HS05, PS06, and HS06. Once artificial snow has settled for a few days, allowing the atmosphere to influence its surface, we notice a significant improvement in its gliding qualities. This change brings us back to standard waxing practices. Here at our end, we understand that adapting to these evolving conditions is critical to ensuring your skis are optimally prepared, delivering the performance you seek.

In temperatures above freezing, snow remains at 0°C (32°F). The water surrounding the snow crystals increases until the snowpack becomes saturated with water. Waxes that are highly water-repellent and coarse base structures are needed.

Snow contamination

Understanding snow contamination is crucial for effective waxing. Soluble dirt changes the chemical properties of the snow, like salts that alter the snow's melting point, creating a thicker lubricating water layer.

Insoluble contaminants, such as macroscopic particles, residues from kick wax, or atmospheric dirt, accumulate on the snow's surface.

When the snow is contaminated, its mechanical properties are changed. This means that the tribology that describes gliding on snow needs to be revised, i.e., the knowledge about waxes and wax selection is changed. Additives like solid lubricants may reduce the friction the contamination imposes, particularly solid particles.

Artificial snow

The main difference between natural and artificial snow is that natural snow crystals freeze from the inside out and grow larger with time.

While natural snow crystals have sharp edges, a more extensive surface area, and a lot of small open spaces between the snow crystals, artificial snow grains are water droplets that freeze from the outside. When the inner part freezes, it expands, and the snow grain may break and leave sharp edges. Artificial snow also has higher density, hardness, and a larger contact area than natural snow.

In every aspect, from temperature to snow type, we focus on providing the knowledge and products you need to be perfectly prepared for any condition.

Snow friction

The low friction experienced when skis are sliding on snow and ice can be explained by a thin film of water between the surfaces created by frictional heat. The frictional heat produced at low speeds and cold temperatures will melt little or no ice to create a lubricating water film, leading to high friction. At this point, we are close to the "dry friction" regime. Adhesive bonds will be created between the ski and snow surfaces, and the frictional force can be explained as the force needed to shear adhesive bonds between the ski surface and the ice/snow surface.

The high friction at low temperatures can also be described by adhesive plowing. A hard ski sole material will deform the less hard snow or ice and create friction.

However, on ice and snow, real dry friction is very rare. Even at very low temperatures, research shows that ice has a thin liquid-like film that lubricates the surface. The film has a thickness of only a few molecular layers. When the velocity or temperature rises, the surfaces will experience increased frictional heat. The friction force is no longer only dependent on the shearing of adhesive bonds or plowing between the surfaces. A lubricating film is generated. This film separates the ski surface from the snow crystals, leading to lower friction. At intermediate freezing temperatures, around -4°C to -10°C (25°F to 14°F), the water film between the frictional partners has the optimal thickness to create low kinetic friction.

Approaching the freezing point, the water film increases in thickness, and when conditions for melting are present, free water enters the system. The contact area between the ski and snow increases, and the friction will increase. Suction gradually builds up as the amount of water increases.

Our snow classification system

We have introduced a simple classification system for snow identification. The symbols help skiers find the best wax for actual conditions.

• Group 1: Falling and newly fallen snow characterized by relatively sharp crystals, demanding relatively hard ski wax.
• Group 2: An intermediate transformation stage, characterized by grains no longer possible to identify as the original snow-crystal shape; often called “fine-grained” snow in ski-wax terminology.
• Group 3: The final stage of transformation. Uniform, rounded, bonded grains characterize the snow surface. Also called “old” snow.
• Group 4: Wet snow. If snow grains in groups 1, 2, or 3 are exposed to warm weather, the result is wet snow.
• Group 5: Frozen or refrozen. When wet snow freezes, it is identified as group 5, characterized by large grains with frozen meltwater in between. The snow surface is hard and icy, requiring a klister as kick wax.