Reprofile angles don’t match

[Marc H]

I log my clamping position the first time I sharpen a knife, with the profile angle used, along with any helpful notes.  A saved digital photo can be helpful, too.

For touchups I clamp the knife back to that recorded position, while setting the adjusters at the same angle setting(s).  I visually inspect my bevels with a USB microscope.  I’m able to skip using a marker most times.  I can usually see clearly if I am dead-on my last bevel angles, with the USB scope.  If the new scratch pattern is not superimposed directly over top the established bevel, I double check the setting with my angle cube, and also check the knife’s position for correctness.  Usually I can get it dead-on.  Even a 0.01° setting inaccuracy can be seen by the new scratch pattern’s position, higher or lower, relative to the first bevel, using a USB scope.

Following any micro-angle re-adjustment needed or knife repositioning, I look to get it back to dead-on, or I keep working at it until it is.  I haven’t come across the situation that the angle changes as steel is removed from multiple sharpening sessions.

Marc
(MarcH's Rack-Its)

[Marc H]

I will add this…I believe the bevel angle setting maybe slightly dynamic.  By that I mean if it were to change, as Joe is suggesting, as steel is removed, over time, using an angle cube to check and micro-angle adjust with each new grit used, you will be essentially starting with the desired bevel angle setting, all over again.  If any variation was caused as a result of the previous grit work, it’ll be reset back to the correct bevel angle again, for the next grit.

After giving this angle/steel discussion some thought I realized once the profiles are established, we are not really changing the bevel angles by removing steel.  If we are consistent in our technique,  with uniform and flat contact between the stones and the bevels, the angles stay exactly the same.  We are really moving the bevel’s position incrementally lower down on the knife, (relative to how it’s clamped), at that same angle, over time.  I would worry more about the steel getting thicker behind the edge as the knife gets shorter in height and therefore thicker.  Not the angle changing.

So by checking angles frequently, we keep it in check.  With the precision of the W.E. allowing that we can match sharpening angles so precisely, very little steel is wasted for touch ups unless the edge damage is substantial requiring more steel to be removed.  The edge damage I’m removing is generally on the micro-level and may be barely noticeable with the naked eye without looking really closely for it.

Marc
(MarcH's Rack-Its)

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