How flat (or not) are my bases? What are my base bevel angles? How straight are my scrapers, edge guides & tools?….are among the typical bits of information needed to perform and gauge quality of work and determine what work is required.
Like any tool we carry, there is a range of quality levels available to meet budget, personal goals and acceptable tolerances. From basic straight metal bars to precise, finely milled, high quality case hardened steel, the DIY tuner can achieve the desired and necessary level of precision using the fundamental tool known as a true bar.
For base work, a good backlighting source like a desk lamp, daylight, flashlight, etc is very important to help you see any variations between the bar and base. By clearly identifying irregularities and locations the guesswork is minimized.
The basic types are rectangular, square or round section bar stock of varying levels of precision and finishes for the recreational tuner, or a highly milled ‘knife edged’ precision true barfor those with tighter tolerances for their boards. A ‘hybrid’ of sorts, is a finely milled base skiver which can also be used for base repair and flattening tasks.
The narrower the section, the less ‘forgiving’ the lighting will be and increase accuracy. A wider square or rectangular bar will allow less light to pass between it and the base versus a round bar and far less than a knife edged bar.By turning a square or rectangular bar stock true bar on edge, you can increase the accuracy, as long as the quality of the bar stock is acceptable.
Typical base issues are flat, high, low (below) or both (as seen above). A perfectly flat base is ideal while some irregularity may be acceptable for some, depending on performance level or typical snow type. A backcountry or powder ski or snowboard has less of a need for perfection than a high performance race ski or snowboard.
Regardless, knowing ‘where they are’ is important.
Additionally, many new skis and snowboards are anything but flat.
A low base (concave) will cause
the edges to ‘rail’ or grab more readily than desired and harder to release, while high
bases (convex) will require more
angulation and time to get to an edge.
Achieving a flat base is also imperative if you also wish to achieve high precision while tuning edges since all bevel angles and tools are relative to an assumed flat base.