Fox, you beat me to it! At least the English speakers knew what he was talking about
Regarding the original topic, from what I understand, with each successive waxing bases get faster, and for this reason serious racers won’t grind their bases unless absolutely necessary. This is due to the absorbent properties of the base, with each wax job they absorb just a little bit more wax into the thin layer of the base.
Perhaps the Chemists among us can confirm this, but is it true that that the standard “wax” we talk about is derived from petroleum (which is why you should never use bees wax as it’s completely different) and is a close cousin to what we call kerosene (paraffin)? The “oxidisation” occurs because the wax has “evaporated” and is simply the bare base without any wax remaining in it. Sealing the base with a thicker layer of wax effectively retains the wax within the base, preventing the need for a base grind and retaining the existing wax in the base (thus producing faster skis). The skis become “railed” as the amount of wax in the base reduces due to a shrinkage of the pores within the base that would otherwise be filled with wax.
One caveat, I have absolutely no qualifications in this area, but have just asked lots of questions over the years.