How to sharpen after hardening (Lansky)

S

syvmn

Joined
Apr 5, 2009
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Hey guys. I just picked up a lanksy sharpener and was wondering what your process is.

My blade is shaped, heat treated and ready to go. However, it still has the "dime's thickness" left on the cutting edge. Actually mine is a little thinner than that but I didn't get any cracks.

Do you just start with the course stone included in the lanksy to get that thickness down or should I use something else to grind it down to a rough edge? I guess I'm just not sure if I should start with the lansky or something else.

Thanks!
 
if you have a belt sander i would rough the edge in first or it will take you quite some time to sharpen it. make sure you go slow and use light pressure. once you have a burr worked up then switch over to the lansky.
 
Sadly all I have is the HF 1x30 that runs at light speed. I'm worried I'll lose my temper (both kinds).
 
I do all my sharpening on a 1x30" from HF (I seem to have better results than on my 2x27"). I do 220, 400, 800, leather. If your worried about over heating, take about 3 swipes and dip. Maybe experiment with and old knife?

David Sharp
 
A dime thickness is much too thick to even dream of starting an edge from. You need to finish grinding first. That edge needs to be at about half, or less a dime thickness before it is ready to sharpen. I would prefer less. The less, the better, unless it is a chopper.
 
LRB said:
A dime thickness is much too thick to even dream of starting an edge from. You need to finish grinding first. That edge needs to be at about half, or less a dime thickness before it is ready to sharpen. I would prefer less. The less, the better, unless it is a chopper.
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richard j said:
if you have a belt sander i would rough the edge in first or it will take you quite some time to sharpen it. make sure you go slow and use light pressure. once you have a burr worked up then switch over to the lansky.
Click to expand...

Both are correct. You can get diamond "stones" for your Lansky which will work faster, but even then you need to have proper thickness and your edge pretty much set first, or it will take forever. Keep in mind that a thin edge that cuts really well is also much easier to touch-up later on down the road. I feel bad for all those poor bastards out there with .100" edges made of "super steels" trying to re-sharp them by hand at some later date ;)
 
The 'dime's thickness' advice is to avoid 1.warping, and 2.decarborization (not sure I spelled that right, but you know what I'm saying)... After the blade is hardened, it will need to be ground down to its final thickness. So all the advice you've gotten is correct.

What you need to do now is grind the edge down to it's final thickness. This means grinding hardened steel, and this means if you overheat it you ruin the temper. Grind without gloves, go slowly, and dip the blade frequently. If the blade starts to feel hot, dip it. Pay special attention to heat near the point. There is some debate among makers as to how thin you want to grind your edge. If the knife is meant for cutting and slicing as opposed to chopping and batoning, here's what I do.

I grind the blade with a flat bevel before heat-treating. Once the blade is heat-treated, I gently convex the bevel (using my belt grinder and a slack belt)to remove the additional dime's thickness. In fact, I grind it down to the point I can feel a burr along the edge, then do my final sanding and finishing (making a point to remove the burr and a bit of the sharpness, otherwise I -will- cut myself at some point). Once the handle is finished, and the sheath, I put a final edge bevel on the blade, usually at about 15 to 18 degrees. This amounts to a slightly convex bevel with a microbevel on the cutting edge, and makes for a wickedly sharp knife that can be easily resharpened. If it is good steel properly heat-treated, it can withstand chopping wood. However, for a dedicated chopper, I will leave a tiny flat on the edge before final sharpening.

Not the only way to do it, and maybe not the best way, but it works well for me and my knives. Hope that helped.
 
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