For that matter, should I have my wife's and mine done as well? They've never been done either.
Pardon the noob question. Just starting to get into tuning and would like to get the season off to a great start.
Unless something very odd is going on, they come from the manufacturer with structure. The purpose of structure is to make the skis run better / faster, not really to make them take wax. While there are skiers who might get a base grind to give the skis the ideal structure for the local or seasonal snow conditions, if any of those skiers are ten-year-olds in a program designed to build general skills (as opposed to, say, J1s in a program designed to get their FIS point into the low double-digits), something is awry.
If the basic geometry is okay - which, given the fact they're a nicer model, may be the case - I would just wax them. No need to fool with a steel brush beforehand. You can check for railed edges pretty easily.
The bases may be slightly concave near the tip (see various other threads on this subject). That's most likely okay (again, see other threads), so long as the edges are level with the bases and have something in the neighborhood of a 1-degree bevel.
All the things that apply to any ski also apply to Junior skis. if they are way out of whack, concave or convex or edges higher then base or way too much base bevel. They need to be stone ground. In order to put a reasonable tune on any ski the base has got to be flat at a minimum 10-20mm in from each edge.
Chanwmr, can't really understand your comment about Adult skis and not to grind a Jr. partiularly race ski??? And these are not any way shape or form RACE STOCK skis! they come beveld from the factory, but as a Junior ski most likely need some work!
they are definetly a Junior ski. Did you see the OP's comment that they have a GS sidecut!
The Junior Gs12 & SL12 have the same sidecut!. this is a Junior ski , not race stockof any kind.. I'm sure he'll be fine on it (I don't believe they make any 130cm Adult Sl12's anyway) as long as the base bevel and side edge bevel is good.
A 2 or 3 degree side edge will be fine. Probably not really riding rails cleanly in a race course at that age anyway.