My knives dull right after sharpening!

[JD62]

What are you using to strop with? Also this is a little better sharpening vid.

 

[YinTx]

Two knives from two different makers with the same problem might indicate it isn't the steel.  Just curious:  what kind of leather are you using it on?  I've heard that some veg tans have clay in them, which is murder on knife edges.  Chrome tans are also hard on edges from what I've experienced.  

YinTx

[Matt S]

I have found that skiving knives, needing to be razor sharp at all times in order to be effective and safe, dull very quickly. This is whether I am using a san mai kiridashi, Swann Morton scalpel, Dixon round knife or English paring knife. For a time I was using disposable scalpel blades but even buying by the hundred that got expensive quickly, especially on chrome tans. Currently I use an equal-bevel kiridashi (so I can pull and push) with amalgamating tape round the handle. It has a very hard core with softer steel sandwiching it. I have to strop very regularly to keep the edge in top form.

[machinehead]

I have both the narrow and wide versions of the knife that Lisa Sorrell sells and they hold an edge well and strop quickly back to super sharp. Lisa uses these knives herself to skive the inlay and overlay pieces for her custom cowboy boots. In case you haven't seen her video on sharpening these knives:

 

 

Edited November 17, 2017 by machinehead

[JeannieH]

I'm using the stropping block from knives plus. I have watched the video on fixing Japanese skiving knives and Lisa sorrels video a while back. I'm skiving 3.5 ounce chrome tanned leather with a soft hand. When I strip, should there be any pressure applied to blade or just lightly pass it over the strop? 

[Matt S]

48 minutes ago, JeannieH said:

I'm using the stropping block from knives plus. I have watched the video on fixing Japanese skiving knives and Lisa sorrels video a while back. I'm skiving 3.5 ounce chrome tanned leather with a soft hand. When I strip, should there be any pressure applied to blade or just lightly pass it over the strop? 

I find best results with lots of pressure, but remembering to keep the angle consistent. Left right left right 12 times as soon as I notice any drag on the knife. Test it on the arm. If it doesn't pop hairs strop again. Repeat until it's hair popping sharp. Then start again as soon as the knife starts to drag.

[JeannieH]

Matt, would that motion of left to right work with the nobuyoshi knife? It only has one angled side...

[Hunhunt]

I have experienced exactly the same problem with a similar knife, the ones sold by Lisa Sorrel. I use a Tormek sharpener and bring the edge to razor sharpness using the stone wheel followed by a stropping wheel. The edge is mirror polished. The knife I use is sharpened on both sides. The knife cuts extremely well but quickly dulls with the chrome tanned leather I use in shoe-making. I have experienced the same thing with the Super Skiver with injector razor insert and with an Osborne french edger/skiver. I make frequent trips to the Tormek stropping wheel to touch up the edge. I have tried varying the angle of the edge but have found little difference. Seems to be the nature of chrome tanned leather and metal edge tools.

[Matt S]

On 11/18/2017 at 3:46 PM, JeannieH said:

Matt, would that motion of left to right work with the nobuyoshi knife? It only has one angled side...

I would do a dozen on the bevel, then one or two with the back of the blade dead flat against the strop to get rid of the burr. Repeat a few times then test as above.

[Grumpymann]

Just a quick question. Are you cutting on a thick Mat? Is there a slash in the mat under your leather? If so I may have the answer to your dilemma.....