This is a more advanced topic than most recreational skiers in the Ottawa area will be interested in. But base preparation of the skate skis is often said to be more important than the glide wax. And there are times when I think that this really true.
You might have noticed that your skis get faster as they get older. You are not mistaken. My two to three year old skis are almost always faster than my new skis, and this is largely attributable to the 'aging' of the P-tex bases. The constant waxing, scraping and skiing seems to make the bases faster. Something not missed by racers who often spend a lot of effort preparing their skis to be fast.
The skis coming from the factory are pretty good, but not perfect. The bases will almost certainly have some bumps, waves or ridges that can be seen when looking at them on a shallow angle. I am going to suggest that these are not very important to the recreational skier. Though higher performance racing types may want to have their skis stone ground to make them flat. This is a process where a cutting tool 'the stone' removes a thin layer of P-tex from the skis.
The P-Tex bases have pores that absorb the ski wax, and it is the matrix of the wax and P-Tex, which seems to make the skis go fast. The waxing process involves melting the glide wax onto the skis, letting the P-Tex absorb the wax, scraping as much of the wax off, then brushing with a nylon brush to remove even more. So the pores are important.
The pores on new skis can sometimes be closed due to the manufacturing process, so they won't absorb wax very well at first. Repeated waxing and scraping helps to open them up. This can take several years for most of us, which is why old skis seem faster than new skis. A second problem is due to P-Tex hairs left over from the cutting process used to make the P-Tex bases. Very old skis are also prone to the hairy's, so they too will benefit from some work.
For those with money, stone grinding will fix both of these problems. But there are cheaper ways to get almost the same effect.
The one is to scrape the bases with a steel blade to cut the P-Tex hairs away, and perhaps open up some of the pores. The blade, which you can buy at a ski shop, is held at an angle to the base (like a butter knife) and then drawn the length of the ski, tip to tail. Really thin shavings should accumulate on the blade, and the bases should take on a bit of a shine. Keep the pressure fairly light and do long strokes so as not to put gouges in the skis. You can back the steel blade with a plastic scraper to stiffen it up a bit.
Alternatively, or even in addition to scraping, you can scrub the bases with 3M Scotch pads (like the green scrub pads from the kitchen). Some ski shops carry a series of these pads from coarse to fine. Scrub the skis from tip to tail in long strokes, gradually working from the coarse pad to the fine pads. It is not clear how many times you need to repeat the scrubbing, but boredom will probably stop you in time. This process should remove most of the hairs.
Now comes the waxing. There is likely dirt in the pores, which needs to be removed. Brushing the bases with a brass brush will get rid of some of this dirt. But hot waxing with a soft wax (i.e. red glide wax) is the next step. Melt the wax into the base, then let cool. Scrape with a plastic scraper. Repeat the waxing/scraping several times. The hot wax should lift the dirt out of the pores and raise the P-tex hairs. Scraping with a plastic scraper will get rid of both. A sharp plastic scraper will make this process a bit easier.
Once cleaned, you can wax the skis with the glide wax for the day. You might want to do this twice, just to make sure that the red wax from before is removed. After scraping with a plastic scraper, brush the skis with a nylon brush to remove the excess wax. Any stiff nylon brush will do, as my first brush came from the grocery store.
Note that for really hard glide waxes (Start Artic, Toko Nordlite) a sharp scraper will cause the wax to shatter off the skis. This is not bad, but dulling the edge of the scraper with some sand paper will stop this (though scraping the wax off will take a bit longer). You can also start the scraping process while the wax is still a bit warm.
A slightly more exotic process is to add structure to the bases (i.e. ridges). The idea is to have shiny smooth bases for really cold snow. As smooth as a baby's bottom when it is really cold (below -15° C).
Near the freezing point and above, moisture in the snow creates suction, which slows the skis down. So rilling the skis (adding grooves) will create channels to let air in, and break the suction. Think of the rain grooves on your car tires. You need to buy a rilling tool to do this. Fine rills are used for colder snow (i.e. 0 to -5° C) and coarse rills for warm wet snow . Draw the tool from the ski tip to tail in one long stroke, with enough pressure to put groves in the skis.
I don't recommend that you go off and work on your skis based on this article alone. But rather you should dig around on the internet, or talk to other skiers or stores sales staff to determine if base prepping is something you want to do (also check out the XC-Ottawa website for some really good advice). And you should probably practice a few times on some old skis that you don't really care about; as wrecking new expensive skis is a bit tragic.
Kevin Gibb is a recreational skier living in the Ottawa Area. He has been skiing since childhood and is regularly found wandering the trails in the Gatineau Park. He spent two years racing with the University of Ottawa Nordic Ski Team where a low VO2 max consigned him to the back of the pack. He then coached the team for 2 years; before becoming Treasurer of the National Capital District of Cross Country Ontario, where he is often seen cutting cheques to pay the bills.
© Kevin Gibb, 2009.