How often should I wax my nordic skis?

As often as necessary.  Wax should be applied consistently to keep user experience and base health at the highest or desired level.  Typically, working with the wax of the day will keep skis clean and enjoyable.  About every 50-100k you should think about using a hard cold wax to “harden” the base.  This newly hardened base will keep bases lubricated and allow retention of the daily wax being applied.

Liquid wax is not a substitute for base care.  Please use liquid wax as a viable option to optimize conditions or as the wax of the day but eventually you will need to iron a hard wax into the ski.  Bases will become visibly gray or dull and need to be refreshed with a hard wax to bring base material back to life.  If base material is gray or dull consider using a hard graphite wax and then a hard green or blue wax prior to next use!