A smooth finish on the skating surface of your blade is the final factor we look for when inspecting for the perfect sharpening. A nice, smooth finish contributes to a near frictionless glide of the skate over the ice surface. Basic science says, the rougher a surface, the more friction created when moving one object over another.
The smoother the surface we can create, the less friction or drag we’ll have when the blades are gliding on ice. If you’ve ever experienced skates that feel sluggish, a rough surface finish could be slowing you down. We’ve found that some of the most experienced sharpeners can hit Even Edges and Sharp Edges while missing on the Smooth Finish.
The Visual Check
A proper sharpening will leave a mirror-like finish with nothing more than very fine lines visible that run the length of the blade.
A rough surface, which typically is visible, oftentimes has a snake skin like or scalloped pattern.
The Fingernail Test
The easiest test for smooth surface finish is to slide the edge of a fingernail lengthwise down the hollow groove that was sharpened into the blade. We apply about a pound of force between the fingernail and the blade.
If the fingernail slides along the blade with a mostly friction-free slide (i.e. if you don’t feel anything) then the skate blade is sufficiently smooth. On the other hand, if the fingernail feels a zipper-like buzzing sensation as it slides down the blade then the surface is not smooth enough and the skate should be corrected.
Whether you prefer a traditional hollow or a flat-bottom profile, a smooth finish matters. In each case, with a proper finish you will reduce friction and waste less energy. As with all of our ESS factors, a smooth finish is also a trademark of good craftsmanship.
Do you sharpen skates? What is your key to getting that perfect, mirror-like finish?