I've tried both ways and can't really tell a difference. The bases aren't completely flat until you base grind them anyways. I haven't cut apart our skis to see if there are any air trapped in between the edges and core.
I haven't worried too much about this either. I just give the skis a good base grind and that makes them pretty good. For the powder skis I make, a flat base hardly makes any difference in performance.
I want to router a groove for the core. It seems that I will need to make the groove a bit bigger to accomodate the fibreglass (not cut deeeper into the core, but taken further towards the centerline of the ski).
How much 'slop' I should build in? I was guessing 2mm on both edges.
Oh yeah and for the guys that are using sidewalls- How wide is your sidewall material? I was thinking of making mine about 8mm.
