For a start, dead flat is the optimum, but how realistic is it? Where I am it is rare to get a ski back from a stone grind dead flat for the whole length, so what is acceptable?
I just got a Jr GS ski back from a stone grind that were almost dead flat over the full length when they went in, and now has a few areas (not over the full length) where it is slightly concave and where at max I can slip a 0.0015 " feeler gauge under the true bar at the center. When looking with a light under the true bar (I use a jointer knife BTW), the gap tapers across the width and gives contact on only about 5 mm max of the base at the edges. If the shoulders were wider (ie 15-20mm) I would just roll my eyes and move on, and accept that I need to ensure the wax is brushed out when prepping the skis. If they did not just have a fresh structure I would probably be tempted to flat file the areas in question to broaden the base contact area, and attempt to to blend them back. So should I bounce these back and have them grind more life off the ski, or not be picky and just suck it up and leave them alone as they are close enough (yes you see light under the true bar, but realistically is one and a half thou enough to make issues)? Someone else is skiing the ski, so its not something I can judge by skiing the ski.
Also what are peoples realistic opinions on what is the acceptable level of flatness before you should go in for a stone grind, and what you should accept back from a shop (in quantifiable terms, ie over how much of the width, shovel vs midfoot vs tail, how many thousands, over how much of the length)? Also would you differentiate between what you would accept for free skiing vs racing?
Thanks for the input.