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Tech Tip # 11: WAXING SKIS FOR
MID-WINTER SNOW |
December 13, 2002 |
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Just because the Sierra Nevada (Spanish for “snow-covered mountains”) has been having a lot of snowfall, this does not mean the skiing conditions are always “perfect”. For example, a week ago we had a storm on Thursday that was pretty wet. By early afternoon the skies cleared, it got really cold fast, and all the tracks froze solid. So the Sierra went from absolute perfect packed powder conditions to death defying frozen tracks in less than 24 hours. By the weekend, the tillers on the grooming machines had made the tracks nice again, but the snow was “old” and abrasive. Now it looks like we’ll have cold powder conditions!! In the course of about a week, we’ve gone thru a complete cycle of snow.
Such conditions are not uncommon in all areas of the country. Powder, a warming trend leading to icy tracks, followed by more (hopefully!) cold powder. The constant in most of these conditions is abrasive snow. New sharp cold snow crystals are abrasive. Snow that remains cold and dries out (from wind or really cold weather), can become almost like sand. Old snow that is warmed, and then gets cold, even with tilling by grooming machines, will become coarse (columnar crystals, from fine to large size).
Over the last 10 years or so, glide waxes for such mid-winter snow conditions have changed considerably. Wax companies have reformulated their waxes to include an increasing amount of synthetic, hard plastic like wax components that give these waxes good abrasion resistance. However, hard synthetic waxes actually have higher coefficients of friction as compared to soft paraffin waxes. Furthermore, plastic wax – by itself – offer poor gliding when there is any significant amount of “free moisture” (liquid water) in the snow. High humidity and sunny weather – even when the temperature is cold – can significantly increase the free moisture content of snow.
So modern cold weather waxes are blended with hybrid fluorocarbon waxes. These are paraffin like molecules that have some of the hydrogen atoms replaced with fluorine. These hybrids mix well with the hard synthetic waxes, lowering the overall coefficient of friction and offering increased glide in moist snow conditions.
There are a few important points to remember when waxing skis with these modern “plastic” waxes:
1) Use a good iron designed for waxing skis. Plastic waxes require hotter iron temperatures that clothes irons cannot adequately maintain. Swix, Toko and Star make excellent wax irons worth the investment ($69-120).
2) Skis need to be warm before waxing. Waxing a cold ski can cause the base to expand while the core does not, leading to delaminations, swelling of the base, or bubbles in the base. Always start with skis that have been at room temperature (70F) for at least one hour. It is OK to wax outside or in a cold room, provided the skis are warm.
3) Constant use of plastic waxes will actually “dry out” the base, which ski manufacturers have determined leads to slow skis and even degradation of the base. It is important to periodically (every 8-10 times) re-wax the skis with a soft wax, such as Star Uniblock Yellow or the new Swix Base Wax. Both are available in bulk sizes at reasonable prices ($9-20).
4) Really hard waxes will not stay in a liquid state when being iron onto the ski, solidifying shortly after the iron is moved away. Trying to make these waxes liquid will overheat the base and can cause delamination. The best way to draw these waxes down into the pores of the ski base is to start by waxing in some soft wax. The soft wax easily drops into the pores. The hard wax will then mix with this soft wax and be pulled into the base. Two coats of each is usually sufficient for proper penetration
5) Skis actually become faster with alternating coats of hard and soft waxes, and everything in between. Skis become increasing fast the more they are waxed. New skis are usually slow and will not start to become “fast” until after 15-20 wax jobs. Skiing between waxing appears to make skis faster. Just waxing alone is not enough. If skis are slow, wax in more alternating coats of soft and hard waxes.
Base (undercoat) waxes significantly improve wax-of-the-day performance and longevity. MAP BLACK by Star is probably the best base wax available. For a complete discussion on how to use this base wax, go to tech tip 8.
Enjoy fast skis. e
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