I am doing the 29km free style race on Sunday, and I need some advice on how to wax my skis for cold (maybe very cold) temperature. Can you help ? Thanks - J.R.
Basically you need to start by making sure you have very little structure in the ski base. In old snow you can sometimes get away with aggressive structure, but not when fresh snow has cooled down quickly and there are very sharp crystals. So, if your skis have big structure you should think about scrapping it out.
Once you've dealt with the structure you are ready to wax. If you've been waxing for the warm conditions lately or you've just scrapped out structure you need to to start with a medium hard wax. I recommend Vauhti Blue (VB), or any mid range wax with NO SILICONE. Silicone wax tends to hang around in the base and on cold days you want very little residual wax in the base, just a hard smooth shinny base is best.
So as the cleaning step apply one layer of the VB, allow to cool just a little and scrape lightly until most of the wax has been removed. Then let the ski cool fully - either at room temperature or outside. Finish scrapping it then brush; first, lightly with a fine brass brush, then aggressively with a nylon brush. This should get the remenants of warm wax and dirt out of your bases. At the same time you will scrape and brush all the little hairs that slow your skis down off the base.
Next, you start with the harder waxes. If the snow is dry and squeaky, then you will want a layer of graphite anti-static. Apply the same way as the VB. After that comes the green of your choice. The past two Keskis (which were very cold!) we've used Vauthi Spektra Green, which we covered with Vauhti BlackFox, and have had amazing skis. If you don't choose an expensive covering layer, you will want to apply 2 layers of green.
Apply one layer of green wax in the same way as the VB. Make sure to brush thouroughly. Are your skis getting shinny yet? They should be! Now, apply a second as before. Now allow your skis to cool outside for ~1 hour, then lightly re-scrape it and then brush it aggressively with a nylon brush.
Notice when you rescraped and brush after cooling the skis outside that you took off more wax? That's because when the ski base cooled off, the pores closed and wax was pushed to the surface. This wax would slow your skis down in dry cold snow until it wore off the base, maybe after 20km. Ever have the feeling that your skis speed up late in the race? Sometimes they do. Cooling the ski outside then rescraping is a great trick to speed up your skis right from the start!