Does the base of a ski oxidize after sliding on snow?
This question was put in front of me on the ski trail Sunday, and I've been thinking on it and doing a little investigating.
Ski bases appear to be made of polyethylene (polyethene, I suppose IUPAC would call it). There are no functional groups at all, just long, long chains of hydrocarbon. Polyethylene is completely saturated with hydrogen. It's nearly unoxidizable, unless you actually set it on fire.
A protective coating of wax on the base reduces the chance of air oxidation even further.
So I have to agree with some forum (I apologize for not having the url here) somewhere: when bases begin to show white (or grey on my black bases) it may be called oxidation in the ski lodge, but that isn't really the issue. Instead, the snow has physically damaged the base by putting lots of tiny little shreds into it, roughing the surface. It is of course real damage to the surface of the ski that will reduce glide, and it is to be avoided. You're overdue for a new coat of wax.
How rapidly this problem develops is going to be largely due to snow conditions when you're on the skis. Watch for it especially after fresh snow, when the snow crystals are still sharp, or when the snow is cold and icy.