Ski wax

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Red Swix grip wax. Used for classic style cross-country skiing when the snow is about 0 °C (32 °F).
Grip wax when applied to a ski.

Ski wax is a material applied to the bottom of skis or snowboards to improve the ski's performance on snow. It can also be applied to other devices that slide over snow and ice such as toboggans. Depending on what activity you are doing, there are many kinds of waxes. You have to think about the snow and temperature, and whether you are racing or cross country skiing and so on.

Types of ski wax[edit]

In general, ski wax can be divided into two major categories: "glide" and "grip" or "kick".

Glide wax[edit]

Glide wax is used by all skiing disciplines. It can offer improved glide speed versus an unwaxed ski.

Glide wax describes a range of waxes which can be applied to Nordic skis, alpine skis, and snowboards. The gliding property of a ski is an attempt to optimize the thickness of the thin film of water between the ski and the snow. Skiing over snow is a combination of both wet friction and dry friction: too much water will create "wet drag" (suction), while too little water will result in "dry drag" (friction). A properly selected glide wax will aid in this delicate balance.

Available glide waxes contain a number of different components to match to prevailing conditions to obtain an ideal water film thickness. Obtaining an ideal water film thickness involves the glide wax contributing to the production of the water film and the removal of excess water; glide waxes contain components for both of these contributions. In conditions where creating sufficient water film are difficult (dry or very cold conditions) glide waxes will have dry friction components added. Adjusting the hardness of the glide wax is the principal method for controlling the contribution to the water film. Harder glide wax will generate more film while softer glide wax will generate less film. When excess water is present then more hydrophobic components are used for film thickness reduction.

There are a number of different components used to reduce wet friction. Paraffin wax, both natural and synthetic, has been a widely used material. Some older materials used have included pine tar and food grade oils. Other materials currently used to control wet friction include but are not limited to silicon, PTFE, flurocarbons, graphite, molybdenum and gallium though all have an effect on the glide wax hardness once added. There are numerous materials that have been used or tried but have been abandoned due to regulation or competition rules.

For controlling the hardness of glide wax the length of the carbon chains in the wax are adjusted. Longer carbon chains create a harder wax while short carbon chains create softer waxes. Microcrystalline waxes are very small allowing for very soft waxes. Other additives that affect hardness include materials also mentioned for wet friction reduction. Various mixtures of these materials will change the overall hardness.

A glide wax is selected based primarily on snow temperature, as well as the crystal structure and relative humidity of the snow. Manufacturers' packages generally provide guidelines for matching a glide wax to the snow conditions. It is applied to the "glide zone" of a ski. For alpine skis, snowboards, Nordic jumping skis, and Telemark skis, the glide zone consists of the entire base, except for the raised tip. For cross-country skis, the glide zone depends on the style of skiing being done. For the skating technique, the entire base is a glide zone, but for the classical technique, the glide zone will be the tips and tails of the ski, but not the kick zone (see below).

However, some authors question necessity to use any glide waxes on modern ski base made of different kinds of Ultra-high-molecular-weight polyethylene (UHMWPE).[1] [2] [3] [4] [5] Other authors insist that the ski base material is much better than any glide waxes.

Grip wax[edit]

Grip wax or "kick wax" describes a variety of waxes specific to cross-country skiing with a classical technique. This wax comes in two forms, "Hard Kick Wax" and "klister". Hard kick wax is a firm substance which comes in a small tin. It is used for new snow with a clearly defined crystal structure, and sometimes for older, cold snow (found when the air temperature is below freezing). In general, it is best used in conditions below freezing. When no kick waxes work, skiers may have to resort to Klister, an amorphous solid which comes in containers similar to toothpaste tubes. Klister is notoriously sticky and deserves its reputation as a difficult wax to use, but is excellent when used in icy conditions (below freezing, when the snow has lost good crystal structure) or with snow that is relatively warm and wet (above freezing). In times when Kick wax and Klister don't produce enough grip, skiers will sometimes make Hairies: a process of turning the skis into waxless cross country skis by roughing up the base significantly. If a skier owns waxless skis, these can be used as well.

Although the nuances of grip waxing are complex, all grip waxes serve the same purpose. The wax is applied to the central portion of the ski called the "kick zone". The kick zone extends from skier's heel to about 15 cm ahead of the binding. However, the size of the kick zone can vary depending on the camber of the ski and the skiers weight. It is important that the skis are checked for proper fit before attempting to use the skis. When enough pressure is applied downward, the camber in the ski is flattened, allowing the kick zone to make contact with the snow. When properly selected and applied, the wax in the kick zone grips the snow and allows the skier to propel him or herself forward. A well selected grip wax will grip the snow and prevent the skier form sliding backwards, allow him/her to move forward, and release its hold on the snow as the pressure on the kick zone is released.

There are a wide variety of materials used for grip wax. Both natural and synthetic materials are used.

Glide waxing process[edit]

Glide waxing is more common than grip waxing, simply because alpine skis, snowboards, waxless cross-country skis, and skate skis can all be treated with glide wax, but only plain cross-country skis need grip wax. Waxless cross-country skis usually have etched gripping surfaces that eliminate the need to apply grip wax. Usually, the process begins with a cleaning of the board by using specifically formulated wax remover (see below), which removes both the old wax and any other dirt that may interfere with the adhesion of the wax. After the bare ski base is exposed, there are typically three methods of waxing:

Hot waxing[edit]

Wax appropriate for the anticipated temperature range is heated up against the iron, melted, and dripped or 'crayoned' onto the base of a ski or snowboard. The wax is then ironed into the base using a heated iron. Softer waxes, better for warmer conditions, require lower iron temperatures than do harder waxes, which are meant for colder conditions and require higher iron temperatures; the appropriate ironing temperature for a given wax is often listed on its packaging. After allowing the base to cool, the excess wax is scraped off. Then the ski is brushed with coarse metal brushes, then softer nylon and horse hair brushes to create a smooth, fast, base. Sometimes, highly fluorinated wax (wax in which many of the bonded hydrogens have been replaced with fluorine) is used to reduce the friction between ski and snow even more.

Paste, liquid, spray-on, and rub-on waxing[edit]

These are the simplest waxing methods. Generally all that is required is to smear, rub, spray or apply a thin layer liquid wax onto the ski's base using a paint brush, then let dry before buffing it into the ski base with a waxing cork. A common misconception is that waxes applied with this method offer the least performance and require frequent re-application. Liquid and spray waxes in particular provide better coverage than solid wax applied with an iron,[citation needed] however to achieve the same durability as hot waxing an iron is used after liquid or spray wax application to maximize penetration of the wax into the base. In addition, some hard waxes, can be applied quickly, as in, before a race, and work effectively as long as they are rubbed in with cork.

Hotboxing[edit]

Another method, hotboxing, consists of applying a wax with an iron, then warming skis in a device called a hotbox. Hotboxes open up the pores in the ski, this allows the recently applied wax to penetrate the base of the ski deeper and more effectively, creating an even faster gliding surface. Hotboxes can be home made—an insulated box with a heater is the basic setup—although commercial made hotboxes are available from manufacturers such as Swix and Toko.

Infrared Waxing[edit]

A recent addition to hot waxing involves the use of infrared light. Wax is applied to a clean base by friction ("crayon" technique or rubbing the wax into the ski base.) The base is then exposed to infrared light which melts the wax into the base structure. The advantage of this technique is that the base does not need to be scraped after application of the wax, merely brushed. This preserves the base structure and reduces the amount of wax used.

Grip waxing process (for classical, non-waxless cross-country skis only)[edit]

Kick Wax[edit]

This comes in three forms: the traditional hard wax in an aluminum tin, as a liquid paste and as a tape. The three forms can be used by recreational, fitness and racing skiers.

Klister wax[edit]

Klister wax comes in a squeeze tube or a spray-on can and is best applied in a warm location. It is squeezed out of its tube onto the kick zone of the ski, and then spread using a paddle or with a thumb.

Hairies[edit]

There are times when neither kick wax nor klister can create effective grip; a technique that is not technically waxing is used to create grip in a particularly specific snow/air temperature (around 0°C) and snow grain (new, abrasive snow). This technique is called "making hairies". The kick zone of the ski is cleaned, then roughened by using fairly coarse sandpaper (usually at least 80 grit). Lastly, a layer of silicone is sprayed over the textured base to discourage ice from sticking to the "hairs" of ptex.

Application tools[edit]

There are a wide variety of tools that can be used to aid in the application of ski wax. For glide waxing the basic tools are typically a waxing iron, a plastic scraper and a nylon brush. For grip waxing a cork (natural or synthetic) for application and a plastic scraper for removal (though not the one used for glide wax).

The potential list of tools is very long and can include: waxing irons, scrapers, profiles/vises, brushes, files, screwdrivers, drills, thermometers, hot boxes, planers, clamps, rillers, special pads, cleaners and respirators. These tools are used not only in the direct application of the wax to the ski, but for the preparation of the ski base before applying the ski wax.

Waxing irons[edit]

Special-purpose ski waxing irons have more accurate temperature controls, and thicker and smoother bases. Thick bases help keep the heat evenly distributed over the iron's surface. The more accurate temperature control means the iron maintains the selected temperature without excessive temperature spikes or drops. All together this results in better wax penetration into the ski base because each wax has an ideal application temperature. The iron's flat base also allows for easy cleaning so that waxes from previous applications do not become mixed with the current application resulting in a contaminated wax mixture.

Clothes irons are an inexpensive alternative to a special purpose waxing iron. These irons can easily heat to temperatures hot enough to melt the wax, but may not be accurate. Clothes irons suffer from relatively thin bases that tend to poorly distribute heat and low quality temperature control which can result in wide temperature variations during application. Clothes irons can often overshoot the desired temperature and scorch the wax, which decreases the performance of the wax and may be harmful to one's health, especially with fluorinated waxes.

When ironing the wax into the base of the ski, the appropriate temperature of the iron must coordinate with the type and temperature of wax being applied. This is because different waxes contain different chemicals that have varied melting points. Also, this will allow the ski to glide across the snow more efficiently. Types of wax should be selected based on the type of snow conditions. A wax used for colder snow temperatures may need to be heated more in order for it to fully melt into the grooves of the base. However, the temperature and placement of the iron may need to be adjusted in order to avoid burning the base. The wax should be liquified onto the base and spread evenly over the entire ski.

In addition, irons should either be placed in a clean area or apply an iron cover to keep the bottom clean, uncontaminated, and free of debris that could potentially damage the base of the skis.

Corks[edit]

Corks come in two materials: natural and synthetic. They come in small and large blocks. The corks are used primarily for the spreading of Nordic grip waxes. But they are also used extensively by Nordic and Alpine skiers for applying the high-end fluorocarbon powders. A special cork on a roller called roto-cork is used for pure fluorocarbon wax applications.

Profiles/Vises[edit]

These help hold the ski or snowboard in place while waxing and/or tuning is performed. There are different profiles and vises for Nordic skis, Alpine skis and snowboards. Some are large and meant to be left fixed on a workbench while others are portable.

Scrapers[edit]

Scrapers are flat plastic or metal tools used to scrape the wax off the base. This step is done between waxing and brushing. Once the wax cools, the excess is removed from the base and then it can be brushed to remove wax from the grooves in the base.

Brushes[edit]

Generally the purpose of brushing is to remove the final thin excess layer of wax from the ski without damaging the bases or changing the structure of the ski base. The specialty brushes are used to prepare the ski base and/or deal with very hard waxes. The wide variety of conditions and waxes require a large array of brushes which vary depending on material, bristle stiffness, bristle diameter and size. While it is unnecessary for recreational skiers to have every kind of brush, more serious skiers and wax technicians will have them all. The brush types include stiff nylon (general purpose), soft nylon (finishing/polishing), horsehair (soft and hard), brass (fine and extra fine), copper, fine steel, coarse steel and combination brushes.

History[edit]

Johannes Scheffer in Argentoratensis Lapponiæ (History of Lapland) in 1673 probably gave the first recorded instruction for ski wax application[1] He advised skiers to use pine tar pitch and rosin. Ski waxing was also documented in 1761.[6]

Beginning around 1854, California gold rush miners held organized downhill ski races (see History of ski racing). They also discovered that bases smeared with dopes brewed from vegetable and/or animal compound helped increase skiing speeds. This led to some of the first commercial ski wax (even though they contained no wax at all), such as Black Dope and Sierra Lighting; both are mainly composed of sperm oil, vegetable oil and pine pitch. However, some instead used paraffin candle wax that melted onto ski bases, and these worked better under colder conditions.

A significant advance for cross country racing was the introduction of klister, for good kick in warm snow; klister was invented and patented in 1913 by Peter Østbye.

Ski waxing has developed into a very complex science, its advancement motivated by ski racing. Many companies are dedicated to ski wax production and have developed full lines of wax to cover every condition for the maximum performance. The most recent great advancement in ski wax has been the use of surfactants and fluorocarbons to increase water and dirt repellency and therefore increase glide.

Surfactants were introduced in 1974 by Hertel Wax. Fluorocarbons were introduced beginning in 1986, as the result of parallel research conducted in California and Norway.

Terry Hertel is a recreational skier from the San Francisco area. He had made money during the Silicon Valley computer boom and in 1972 introduced the original ski Hot Wax applicator drum for home use. To go with it he invented a line of high-melting-point paraffin waxes branded as Hot Sauce. As a Lake Tahoe skier, Hertel was fascinated with the problem of glide at all temperatures of snow. In 1974 he formulated a surfactant to his paraffin wax to produce an all temperature wax he trademarked HotSauce. A surfactant is a wetting agent, the exact opposite of a hydrophobic agent. Surfactants are closely related to detergents: they shouldn’t normally work as hydrophobes. But the stuff Hertel used, sodium dodecyl sulfate (SDS), is an odd columnar molecule with a hydrophobic end. Suspended in wax, the molecules clump into spheres with their hydrophobic ends out, making a kind of water-repellent ball bearing.[7] Hertel said his surfactant ingredient was "microencapsulated", referring to a common technique using SDS and related surfactants in pharmaceutical preparation.[8] Super HotSauce earned an insiders’ reputation for great glide in heavy snow. Town racers liked it. HotSauce gives the skier and snowboarder additional control.

A couple of years later, Hertel started research for a "Spring Solution", something that would work in very wet snow but repel the pine pollen, diesel exhaust particles and other dirt that darkened the ski slope snow in April and May. He tried polypropylene glycol, a food-grade antifreeze used to keep ice cream from melting, and it worked. But he also talked to Rob Hunter, a chemist at 3M, who mentioned that the company sold a liquid fluorocarbon to the cosmetics and paint industries: it dried to a smooth, glossy surface. Hunter thought the liquid fluorocarbon would work well in a ski wax at colder temperatures, but warned that at $1000 per pound, it was far too expensive.

Hertel wound up buying the 3M perfluorocarbon liquid in five-gallon drums, formulated it into a high-strength candle wax called Paraflint, and in 1986 introduced a hard block wax he called Racing Fluorocarbon 739. It was very hydrophobic, and very fast. (Perfluoro means that all the lateral links in the polymer chain, not just some of them, are capped with fluorine atoms.) Hertel invented White Gold a high performance racing wax by formulating perfluoropolyether diol with the SDS formula.

Meanwhile, at Swix, chief chemist Leif Torgersen was also looking for something to repel dirt. A hard glide wax was essential to last throughout a 50 km race or a ski marathon, but the softer kick wax picked up pine pollen and other dirt, slowing the ski progressively through the course of the race. So he sought a form of fluorocarbon that could be ironed into the base. In Italy, he found it: Enrico Traverso at Enichem SpA, a state-owned industrial giant, had a fluorcarbon powder with a melting temperature just a few degrees below that that of sintered polyethylene. That meant that if you were careful, you could iron it without destroying the ski base. Enichem had no other commercial customers for the material, but were willing to produce small, expensive lots for use in ski waxes.

Swix began experimenting with the stuff on race courses and found that it improved glide by about 2 percent over the best non-fluorocarbon waxes. In 1990 the company introduced a commercial version called Cera F (cera is Italian for wax). The price: $100 for 30 grams. The parents of young racers screamed in agony: apparently you couldn’t win without it. Fortunately, a little went a long way. Speed skier C.J. Mueller remembers waxing his skis with the scrapings from another competitor’s skis.

Belatedly, it occurred to the various parties in this technology race to patent their products. On March 2, 1990, Enichem applied for an Italian patent on a "ski lubricant comprising paraffinic wax and hydrocarbon compounds containing a perfluorocarbon segment".[9] The same day, Hertel filed for a U.S. patent on a "ski wax for use with sintered-base snow skis",[10] containing paraffin, a hardener wax, roughly 1% per-fluoroether diol, and 2% SDS surfactant". Enichem received a U.S. patent a year later.

These are the two earliest patents for fluorocarbon ski waxes. Later patents have been granted to Dupont and to Athanasios Karydas, Technical Director (and owner) of DOMINATOR Race Wax, a U.S. company (dominatorwax.com).

Hertel claims his Racing Fluorocarbon 739 product quickly found its way into the waxing kits of World Cup technicians and has been used in a number of medal-winning performances. However, he’s never been a member of any alpine supplier pool (minimum annual buy-in costs $50,000). Hertel has provided specialized waxes for freestyle aerials, because in corn-snow conditions are rough at the entry to a kicker and can hold a large volume of water. European companies Swix, Toko, Holmenkol, Briko, and Maplus, who comprise the supplier pools for ski wax, don’t talk about the advanced technology they may be using on World Cup skis.

Wax solvents[edit]

Wax can be dissolved by nonpolar solvents like gasoline, benzene (carcinogenic) or mineral spirits. However commercial wax solvents are made from citrus oil, which is less toxic, harder to ignite, and least damaging (if at all) to the ski base.

Health and Environmental Impacts[edit]

Health Impacts[edit]

Ski wax can contain toxic chemicals including perfluorinated chemicals. Levels of perfluorinated carboxylates, especially perfluorooctanoic acid, are known to increase dramatically in ski wax technicians during the ski season.[11] PFOA, in particular, is known to be stable in the environment and to cause cancer, birth defects, thyroid dysfunction,[12] increased cardiovascular risk,[13] hormone and immune system disruption, birth and developmental defects and liver toxicity [14]

Environmental Impacts[edit]

When skiing, the friction between the snow and skis will cause the wax to rub off on the snow and sorb to the snow grain surface and particles in the bulk snow. The wax is released in the snowmelt in pulses depending on the hydrophobicity of the chemicals in the wax and the age of the snowpack, ending up on the soil surface.[15] This snowmelt drains into watersheds, streams, lakes and rivers, with the potential to contaminate and harm both the environment and its inhabitants. PFCs in ski wax are extremely heat resistant, chemically and biologically stable, and thus environmentally persistent.[16] A University of New Hampshire undergraduate named Evelyn French estimates of the amount of PFOA in ski wax released to the environment at a ski resort approximates that 1 million skiers visit the resort in a year, each using ¾ of an ounce of wax, resulting in 46,875 pounds of PFOA deposited in the surrounding soil and water systems. To extrapolate to the US as a whole, the ~60 million ski visits each year result in ~2.8 million pounds of PFOA being released to the environment.[17] French's arithmetic, however, has been challenged. Because of its expense, no wax company uses more than a 1% concentration of FHCs in any bulk wax, so even if all American skiers used FHC wax every day, the total FHC burden would be on the order of 28,000 pounds (about 13 metric tonnes). Moreover, the bulk of those FHC materials go not into the watershed, but onto the waxing room floor in the form of scrapings, to be bagged as landfill trash or recycling. [18]

References[edit]

  1. ^ a b Kuzmin, Leonid (2006). Investigation of the most essential factors influencing ski glide (Licentiate). Luleå University of Technology. Retrieved 2012-10-20. 
  2. ^ Kuzmin, Leonid; Tinnsten, Mats (2006). "Dirt absorption on the ski running surface - quantification and influence on the gliding ability". Sports Engineering 9 (13): 137–146. doi:10.1007/BF02844115. Retrieved 2012-10-20. 
  3. ^ Coupe, Richard (2008). "An Investigation Comparing the Efficacy of Different Lubricants for Skis on Artificial Snow". ENQUIRY: The ACES Journal of Undergraduate Research (Sheffield Hallam University) 1 (1). Retrieved 2012-10-20. 
  4. ^ Giesbrecht, Jan Lukas (2010). Polymers on snow: Towards skiing faster (Doctoral). Swiss Federal Institute of Technology. Retrieved 2012-10-20. 
  5. ^ Kuzmin, Leonid (2010). Interfacial kinetic ski friction (Doctoral). Mid Sweden University. Retrieved 2012-10-20. 
  6. ^ Oberleutnant Hals. Om Skismøring. Vaage: Skienes Verden. p. 254. 
  7. ^ "Critical micelle concentration (CMC)". OpenWetWare. 2009-08-05. Retrieved 2010-05-10. 
  8. ^ "The effect of surfactants on the microencapsulation and release of phenobarbitone from gelatin-acacia complex coacervate microcapsules". Journal of Microencapsulation (Informa Healthcare) 3 (2): 89–93. 1994-01-01. doi:10.3109/02652048609031562. Retrieved 2010-05-10. 
  9. ^ US patent 5202041, "Ski lubricant comprising paraffinic wax and a hydrocarbon compound", issued Apr 13, 1993, assigned to Enichem Synthesis S.p.A. 
  10. ^ US patent 5114482, Terry J. Hertel, "Ski wax for use with sintered base snow skis", issued May 19, 1992 
  11. ^ A time trend study of significantly elevated perfluorocarboxylate levels in humans after using fluorinated ski wax., Nilsson H, Kärrman A, Westberg H, Rotander A, van Bavel B, Lindström G. Environ Sci Technol. 2010 Mar 15;44(6):2150-5.
  12. ^ Association between Serum Perfluorooctanoic Acid (PFOA) and Thyroid Disease in the U.S. National Health and Nutrition Examination Survey., David Melzer, Neil Rice, Michael H. Depledge, William E. Henley, Tamara S. Galloway Environ Health Perspect 118:686-692. doi:10.1289/ehp.0901584.
  13. ^ Ski wax chemicals build up in people's blood, pose risks., Cherly Katz Environmental Health News, December 19, 2010.
  14. ^ Lau C, Anitole K, Hodes C, Lai D, Pfahles-Hutchens A, Seed J (October 2007). "Perfluoroalkyl acids: a review of monitoring and toxicological findings". Toxicol. Sci. 99 (2): 366–94. doi:10.1093/toxsci/kfm128. PMID 17519394. 
  15. ^ Plassmann, Merle M. "Environmental Occurrence and Fate of Semifluorinated N-alkanes and Perfluorinated Alkyl Acids Present in Ski Waxes." Doctoral Thesis in Applied Environmental Science at Stockholm University (2011).
  16. ^ Bull, S. "PFOS + PFOA Toxicological Overview." Health Protection Agency. 2009. Web. 25 Mar. 2012. <http://www.hpa.org.uk/webc/HPAwebFile/HPAweb_C/1246260032570>.
  17. ^ French, Evelyn. "Waxing for a Greener Tomorrow." Ski Wax and Snowboard Wax. 2010. Web. 28 Mar. 2012. <http://www.purlwax.com/home-page/waxing-in-environmental-news/>.
  18. ^ Masia, Seth. "History of Ski Wax" http://skiinghistory.org/history/grip-and-glide-short-history-ski-wax

External links[edit]