While sharpening and polishing side edges and in order to cut the metal side edge only, the sidewall material needs to be planed or back-filed. Otherwise the cutting tool will get clogged with the sidewall material and reduce the efficiency and possibly the accuracy of the desired bevel.
A Sidewall Planer with a round carbide blade or bit will remove a nice, clean fillet along the edge which can be further sanded to smooth out any irregularities and provide a smooth surface.
Here’s a clip from the SVST Tuning & Waxing DVD on SideWall Planing:
As a specialized tool, it can be a bit pricey for the casual tuner, however. A viable alternative is to use an adjustable multi-angle guide or a dedicated edge guide with a short panzer or coarse file to cut back the sidewall so the diamond, stone or file cutting tools are not obstructed.
The Tools4Boards Razor or Xact work very well as multi-angled tools when set from 5° to 6°. So do dedicated edge guides of 5°/85°/95° to 7°/83°/97°.
The T4B Razor is shown
1) Position of the panzer or coarse file in Razor to just get past the sidewall:
2) Side view of 5° peg position and tilted razor beyond the edge and contact with the sidewall.
3) Side view of file on sidewall.