Uneven bevels when reprofiling

S

Swedge

Joined
Dec 23, 2008
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334
When I use a SharpMaker, I sometimes get uneven bevels when I am reprofiling. I find that the coarse SM rods are too slow for taking off a lot of steel, and so I tie a DMT continuous diamond surface extra-coarse or coarse 6" stone onto the SM rods (using rubber bands on the top and bottom of the plate).

I don't alternate every other stroke when reprofiling since I have only one plate and alternating requires moving the rod/plate combo to the slot for the other rod (or moving to the opposite side of the table). Though I don't count the strokes on each side, I think I am doing roughly the same number of strokes on each side.

But often the bevels come out uneven, with one side showing a higher shoulder than the other. What are the possible causes of that?

I am trying to keep the blade perpendicular to the base of the SM, and I think I am (but maybe not).
 
The most common reason is uneven blade grinds, its more common than you think.
 
I assumed that if I was reprofiling the blade, I would automatically correct for uneven grinds (assuming I was doing my part correctly). Was my assumption wrong?
 
If the blade is made off center from the manufacturer, then when you reprofile, you will have uneven bevels. Sometimes as the blade wears and after repeated sharpening, it starts to even out.
 
you correct the sharpening, the grind is the primary bevel that the manufacturer put on the blade itself i doubt you are doing regrinds on a sharpmaker :D

and if this primary grind is uneven you'll have varying thickness at the edge wich will give you uneven bevels.
 
pwet said:
you correct the sharpening, the grind is the primary bevel that the manufacturer put on the blade itself i doubt you are doing regrinds on a sharpmaker :D

and if this primary grind is uneven you'll have varying thickness at the edge wich will give you uneven bevels.
Click to expand...

And this cannot be repaired through conventional sharpening. Repair of this sort of thing is called regrinding...and the process is not for novices. Grinding a blade properly by hand is something that even veteran knife makers can screw up occasionally...fixing an already uneven grind adds yet another layer of difficulty.

On the up side. A slightly uneven grind will go completely un-noticed by most users and will not significantly affect performance of a knife...so do not get too upset if you notice this on a reasonably priced "user" knife...it is pretty common (especially when guys start to become keener observers/knife aficionados).
 
I always count the strokes on each side to ensure that my edge is centered. You can probably get your edge recentered by eyeballing the operation. After that, count.
 
I have a custom knife that is ground badly uneven. I did the exact same thing as you, rubberband some coarse diamond stones to ceramic rods, then worked one side and the other. That made it a little better, but its still very noticeable.
 
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