Tuning the side edge(s) will raise a hanging burr on the newly sharpened junction of the base & side angles. You often can’t see this burr but you can feel it if you pull your fingers across your base edge towards your side edge. This burr often mistakenly makes the ski edge feel sharp to the uninitiated. The edge may feel sharp to a thumb rubbed across it & it may remove a sliver of fingernail drawn across it, however, if you slide a piece of fiberleen or tissue down a burred edge it will snag on the ragged edge. Unless the burr is removed so the edge is still sharp but also smooth & snag free the ski’s performance will be totally erratic as the burr sticks straight down into the snow as a continuation of your side edge and makes your skis very grabby and unpredictable. It will cause the skis to be difficult to roll on & off edge smoothly & make them feel twitchy. This is one step which is often critically omitted with a shop tune.

Position the ski up on it’s side in the vice with the base away from you, as you would do to tune the side edge. Use a gummi stone (a 1500 grit Moonflex diamond stone or a hard ceramic/arkansas stone works equally as well) flat against the base edge. Use your thumb as a guide on the side wall & with light to medium pressure make a couple of full length passes, making sure the stone is in contact flat on the base edge. I usually have about one third of the stone above the side edge. It makes the final edge ultra smooth & does not detune or take away any sharpness. Wipe down the edges with a piece of fiberleen cloth.