Ski tuning

When I go around on cross-country skis, I like feeling them sliding adequately on the snow. As they are meant to work on flat ground and uphill, as well as downhill, most of the time my weight will work against them, and a well prepared ski surface makes the difference between a peaceful and pleasant tour and very, very sore legs at the end of the day.

I like to think that ski tuning is not a difficult task at all. It requires very little equipment and simple manual skills, which can be easily acquired with a few trials. Of course, I am not speaking of the refined art of racing ski preparation, which involves high costs, training, and a great deal of experience. I have gathered in this page the steps I follow in order to tune my skis for a one-day winter trip on a beaten track. The information is by no means absolute, but represents my personal way of doing things. I consider it very introductory and certainly not up to ski-racing levels, but for touring purposes it has always seemed to work fine.

How cross-country skis work

If you put skis meant for the classic techinque on the ground and you stand on them, you will notice that they touch down only on the tip and heel, while in the middle they do not touch the ground at all. So, when you are sliding forward on the snow, you are actually sliding on the tip and heel. The centre touches the ground only when the ski is dynamically loaded during the stride. During this moment, the centre of the ski 'locks' to the snow, in order to allow pushing forward.

The tip and heel of the ski must therefore be treated in order to slide as much as possible. For this reason, they are coated with a paraffin-based glide wax. The centre of the ski must be coated with kick wax (also called grip wax), a 'glue' that sticks to the snow during the stride only, and that glides freely when it is not loaded.

Skating skis are somewhat different in the fact that they are meant not to stick on the snow at all. Actually, they are used as a very long pair of skates. To all practical purposes, they should be coated with glide wax over the full length.

Wax will work only if the ski surface is properly grooved with a fine and regular pattern. A groove structure is therefore cut into the sole of skis.

In order to avoid the kick waxing chore, there are waxless skis, with 'dimples' in the centre, or with a chemically modified middle portion. It must however be considered that the tip and heel of such skis should be glide waxed as much as on ordinary ones. Because of the decrease in performance of such modified skis and of the simplicity of basic kick waxing, I feel that these solutions do not present any real advantage, except in very peculiar snow conditions (e.g. during a snowfall), and may actually be a disadvantage even to beginners, as they tend to be slower and much less stable than properly prepared ordinary smooth skis.

When to tune the skis

During use, both kick and glide wax wear off. Once you get used to the feeling of well-waxed skis, a well prepared glide wax will not last longer than a single mid-length excursion, and you will feel the need to wax every day or two. Moreover, the skis should never be left unwaxed for longer than a few days, especially in a warm climate (as when storing them for the summer), as they tend to become rough and 'dry'. The minimal maintenance to avoid gross damage to the skis is therefore a 'storage' waxing at the end of the season, and a re-waxing at the beginning of the next one.

Kick waxing is needed at the beginning of every excursion, and must be adapted to the snow conditions whenever they change significantly. Typically, this will mean retouching kick wax at least every significant stop (e.g., lunch break), and sometimes even more frequently. If possible, kick wax should not be left on the skis after use, but cleaned off immediately.

Please note that new skis are sold as not waxed. On new skis, round off (un-sharpen) the edges with very fine sandpaper pulled in the direction from tip to heel, and proceed with glide and kick waxing.

Occasionally, when you run into a stone or a tree root, you will damage the ski surface. In general, for excursion use, the damage can easily be repaired. After a bit of practice, surface inspection and damage repair becomes a natural step in the ski tuning procedure.

Ski tuning equipment

Photograph of the equipment required for ski tuning
Cross-country ski tuning equipment

For the full sequence of tuning steps, a basic but complete equipment set consists of:

To this you will eventually end up by adding:

For all ski tuning, work in a well ventilated area, as the process gives off all sorts of gases, smells and odours, and some may be quite bad for your health. As the process involves heat, beware of fire hazards. Keep away fom flammable stuff and, if possible, keep an extinguisher handy. Please note that waxes are very flammable. And please (disclaimer...), even though I try being accurate in my description, if you are doing the job, you take the full responsibility for it.

Tuning step 1: repairing damage

Repairing the base surface is my first tuning step. After the full ski base tuning, properly made repairs are almost totally invisible. It may be useful trying this step first on an old pair of skis.

To repair a hole or a bad scratch in the surface:

In my experience, chipped edges can be repired, even if the repair tends to be somewhat weaker than for holes. It is however essential to work accurately, as ragged edges may slow down the skis more than the original damage. Proceed only after some practice, and always evaluate the possibility of leaving the edge as it is, just sanding down the sharp chips with fine sandpaper from tip to heel. To repair edges, proceed as with holes, but:

To repair chips and voids in the wood structure, fill them with two-component epoxy. Inspect the ski carefully, to evaluate whether the crack has weakened it, compromising safety.

After a high number of repairs, or to renew a 'dry' surface, the ski may need to be fully resurfaced. I normally do the job at home with the basic equipment. The principle is to use the bronze brush with enough pressure as to 'lift off' the surface, and then to smooth it out by shaving it with the steel scraper. As the job needs a good bit of 'feel' on how it goes on, it is better, at the beginning, to have it done by a professional ski repair shop, that is typically equipped to do it quickly and efficiently.

Even if it is not strictly a ski repair, occasionally you will have to change a cracked pole tip:

Tuning step 2: structure

Before the actual waxing, inspect the base structure. If the structure is not cleanly visible on the whole ski length, it will need to be cut again. This will tipically happen after large repairs, or after some heavy skiing in very cold snow. Do this on both skis, to maintain them symmetrical. Just lock each ski in the vise, clean them from dirt, and drag the surfacing tool from tip to heel in one go, applying a moderate but firm pressure according to the tool manufacturer's instructions. Do not cut the new structure in a damaged surface or in a partially cut old structure, but repair the skis first if needed.

A couple of tricks:

Tuning step 3: glide wax (paraffin)

Glide waxes are applied on the tip and heel of classic skis, and on the whole base surface of skating skis. When the skis are loaded, they will press on the snow and partially melt it. The least the skis sticks to water, the faster they will glide. To this purpose, the softer and 'greasier' the glide wax, the better. If the wax is too soft, however, the snow will cut into the wax layer, slowing them down and eventually wearing the wax away.

As snow hardness changes with temperature (the colder, the harder), the glide wax should be adapted to the snow temperature. Moreover, if the snow is very damp, a fluorinated wax may be used to help things go better. It must however be noted that fluorinated waxes, if exposed to a flame, will give off poisonous gases. Never use fluorinated waxes with an open flame or a gas torch. Do not smoke while applying fluorinated waxes. Moreover, fluorinated waxes are by far more expensive than plain ones, and may represent a pollution problem in skiing resorts. For these reasons, I use only plain waxes. I avoid fluorinated waxes, and I do not keep them in my standard equipment.

The different waxes for different snow temperatures are marked by their colour. Every maker has its own colour scale; as a rule of thumb, many makers loosely follow a basic scheme:

Warm snow
Snow just below freezing point
Cold snow
Very cold snow

The temperatures are not referred to any specific maker, and are purely indicative. The better the glide wax is thinned down and polished after application, the least sensitive the skis will be to temperature and the longer the wax will last. So, spending some time in proper glide waxing is well worth the trouble. In general, for excursion use a well polished wax will more or less glide on any snow, with the exception of yellow or red wax on very cold snows (the wax will wear out quickly) and of green wax on warm snow (the skis will 'drag').

To the standard scale, most makers will add a general purpose 'white' wax, which may often be the cheapest of the series. It is normally a rather soft wax, meant to be mixed to the other ones in some snow conditions. I find it much more useful to prepare the surface of skis which have 'dried out' too much, to store skis for the summer (see further on in this page), and to clean the ski surface. In emergencies, it may well be used (well polished!) for actual glide waxing, even though, if I wax at home and I don't know anything about the snow conditions, I would rather apply red wax in early winter and blue wax when I expect colder and older snow.

My choice is a set of white (large pack), yellow, red, blue, green, and ultra-low-temperature green non-fluor waxes. An even more basic set could be white (large pack), red, and blue or green. I buy the cheapest, and rely on accurate waxing to get the most out of them. They have always been satisfactory to all practical puropses.

Now to the actual waxing procedure. For each ski:

For a fast wax touch-up, I rub the wax stick as a crayon on the surface, rather than dripping it on. I then heat the wax on the base surface with the iron and proceed with polishing in the ordinary way. With 'cold' (blue or green) waxes, the rubbing may have to be repeated twice, heating the base surface between the two passes. Some care must be taken in fully covering the surface and in avoiding too much pressure, that will spoil the structure. Rubbing quickly heats up the stick and helps the wax transfer.

When you are skiing, it may be useful to carry around an odd lump of any old glide wax or, better, a bit of glide wax tin-canned like the kick-waxes (see next tuning step). It can be applied 'cold' by rubbing it on the tip and heel, if you desperately need to wax on-site.

Tuning step 4: kick wax

Kick waxes are applied on the centre of classic skis. During the push stride, the skis are pressed onto the snow. In that moment, and in that moment only, the snow cuts into the wax, locking the skis onto the ground and allowing the skier to push themselves forward. Since the snow does not adhere to the wax, as soon as the pressure is released, the skis unlock from the ground and slide.

Again, as snow hardness changes with the snow conditions, the kick wax should be adapted to the snow. Too hard a wax ends up in skis which do not anchor to the ground, and too soft or too sticky in skis which anchor to the ground as permamently as a good pair of walking boots.

The first decision to take when kick waxing, depends on what kind of snow you are going to ski on. On new snow (that falls off from your hands if you try to scoop it up, and that is difficult to form into a snowball) you need to apply the kind of kick waxes that come as solid sticks, often packaged in tiny tin cans. On transformed snow (snow that has been heated by the sun and re-frozen a few times, that is scooped up as a lump, and that forms easily into snowballs) you are likely to need the kind of wax that looks like glue packaged into toothpaste-like tubes, and that is absolutely the stickiest and messiest stuff on the face of our planet.

You will then need to measure the snow temperature, choose the wax, and apply it accordingly. Again, kick waxes are colour-coded, with a coding that depends on the manufacturer. For solid wax sticks (new snow), some colours may come in a plain, a super and/or a special variants, for slightly warmer and/or colder snows than the respective plain versions.'Universal' solid kick waxes (touring waxes), that with a couple of waxes are supposed to cover the whole temperature range, are still sold in some places. They simply do not work, and the ones meant for warmer conditions look like tarmac and smell like hell.

For toothpaste-tubed 'glues' (transformed snow), the situation is somewhat simpler. On our Alps, most skiing can be done with just a wax for cold snows (bright blue in colour, also referred to as skare) and one for warm snows (bright red, klister). Intermediate properties can be obtained by mixing the two, as explained later. If you are crazy enough to go skiing when it's raining you will also need a yellowish toothpastish muck, that I will not even mention any more. It is also possible to find an 'universal' glue that seems to work somehow in most reasonable transformed-snow conditions, but is never totally satisfactory.

In all, a very basic kick waxing set could be composed by solid red, white, blue and green, and tubed skare and klister. I have seen that, as solid kick waxes are not expensive at all and last very long, it is well worth expanding the set to the full range. A very useful addition to the set is a bit of hand-washing compound, such as the gritty soap used in mechanics workshops, stored in a small plastic container.

The application of the kick wax must be done on-site, as it critically depends on snow conditions. So, on-site, before skiing:

If you decide for a solid wax:

Photograph of a person holding a ski for kick waxing
Holding a ski for kick waxing

If you decide for a skare or klister

Photograph of a person spreading klister on a ski
Spreading klister

Of course, the main trick is in choosing the wax. A bit of trial-and-error is the best tutor. In a week, you will be able to get your skis going in most reasonable conditions. As a guide, a wax that is too soft (too 'warm') sticks too much, and too 'cold' a wax sticks too little. The possible scenarios are:

Necessary Applied Effect Action
Cold-snow solid wax
Cold-snow solid wax
Ski and have fun!
Warm-snow solid wax The skis tend to lock on the snow. Try covering the wrong wax with the correct one. If unsuccesful, clean the skis and re-wax.
Skare or klister
The skis lock on the snow like crazy.
Sorry, you are in trouble. Clean the skis thoroughly (a messy job) and re-wax.
Warm-snow solid wax Cold-snow solid wax The skis glide as if no wax has been applied. Try covering the wrong wax with the correct one.
Warm-snow solid wax
Ski and have fun!
Skare or klister
The skis lock on the snow like crazy.
Sorry, you are in trouble. Clean the skis thoroughly (a messy job) and re-wax.
Skare (cold-snow paste wax) Solid wax (warm- or cold-snow) The skis more or less work, but the wax lasts a few seconds only. Try covering the wrong wax with skare.
Ski, have fun, and feel lucky!
Klister The skis more or less work, sticking to the snow a bit too much. Try skiing. Before cleaning the skis (a messy job) and re-waxing, think twice.
Klister (warm-snow paste wax) Solid wax (warm- or cold-snow) The skis more or less work, but the wax lasts a few seconds only. Try covering the wrong wax with klister.
Skare The skis more or less work, sticking to the snow a bit too little. Try skiing. Before cleaning the skis (a messy job) and re-waxing, think twice.
Ski, have fun, and feel lucky!

A few tips:

After skiing: cleaning up the muck

After skiing, kick wax tends to harden and, after a few days, it may become difficult to remove. To carry them around, never squeeze the skis with the two centre portions touching each other. Not only this may this damage the ski elasticity. If the skis are properly kick-waxed, they may very effectively stick together, giving you a tough job in separating them again. If this happens, take them inside to warm them up and to soften the kick wax, and slowly detach them, grabbing them by the tails and rotating one ski against the other. Do not grab them by the tips, as this twists them badly. Gentle heating with a hair drier may help. Almost certainly, after such rough treatment, you will have to glide wax.

So, after skiing, clean the skis. Place them in the vise, and use solvent and paper to remove the kick wax. Do not let the solvent and wax go onto the tip and heel, as this spoils the glide waxing. With solid wax, this is a straightforward job. With skare and klister, proceed a little at a time. Mentally divide the centre part of the skis in short portions, and clean a portion completely before proceeding with the next. This will help in actually getting the wax on the paper, rather than everywhere else but the intended destination. Always proceed towards the centre of the waxed section, as it helps in keeping the kick wax away from the tip and heel.

If you need to store the skis tied together, do not flex them. Rather, place them sole-to-sole, touching at the tip and heel only, interposing a bit of greaseproof paper where they touch, and bind them together just there. Rubber rings cut from an old bicycle tyre work just fine.

Storing the skis for the summer

If you need to store the skis for a long period of time (as in the summer), clean and wax them thoroughly on the full length with soft (e.g. white or yellow) glide wax. Do not however thin it down or polish it, as a thick wax layer effectively protects the base surface from oxidation, dust and scratches.

This wax will be removed and renewed at the beginning of the next skiing season. When the new season begins, on classic skis, after removing and polishing this protective wax, you will need to rub the centre of the skis vigorously with solvent, in order to help the first kick-waxing processes. A 'mock' kick waxing with a soft kick wax or klister and subsequent wax removal helps in restoring the centre of the ski to working conditions.

Again, if you need to store the skis tied together, do not flex them. Rather, place them sole-to-sole, touching at the tip and heel only, interposing a bit of greaseproof paper where they touch, and bind them together just there. Try not to store the skis sole-up, as this ends up in a thick layer of dust that will have to be removed when the skis will be used again.

A bit of silicone lubricant sprayed in the binding helps in preventing jamming. To protect the bindings from dust, wrap the centre of the skis in an old newspaper. Do not use plastic, as it traps moisture.

A few final notes

In general, ski tuning is an integral part of cross-country skiing, as much as pitch tuning is part of violin playing. Eventually, the tuning becomes a personal feeling as much as the skiing itself, to the point of feeling robbed of part of the fun when it has to be done by a ski repair shop. Just try it!