Putting a WE on a Roselli UHC Carpenter (65 hardness)

[John]

I’ve been using my Roselli for my fishing knife and it’s almost time to try to put an edge (new?) with my WE130 and a good assortment of stones. I’ve never sharpened a scandal grind with anywhere near the steel hardness that this has (65 to 66). Any guidance would be appreciated.

[Marc H]

John, I have a large and diverse knife collection made from a variety of steels of many different steel hardness.  I have carbon steels, high carbon steels, stainless steels and super hard powdered tool steels. The hardness of my knives range from HRc 56-58 to HRc 67-68.  

I have found no direct correlation between hardness and ease of sharpening.   In the most general terms, the softer steels seem easier to sharpen then the harder steels.  I used to believe that the non-stainless carbon steels and high carbon steels sharpened easier then the stainless steels.  Over time, as my sharpening experience with more different steels has increased, as has my knife collection, this theory was disproved.  

I have no direct correlation between the different steels, steel hardness and ease of sharpening these steels.  First, realize, the same steels can be produced and hardened and tempered at different levels, by different steel makers and different knife makers.  I have experienced completely different sharpening experiences with supposedly precisely the same steel used to make two knives by two different knife makers. 

I have found harder Rockwell C rated, (HRc), steels that sharpened like butter and softer rated steels that were super tough to sharpen.  Some softer steels may sharpen smoothly, easily and effortlessly, just the same as a much harder rated steel.  Then I’ve experienced much lower hardness rated steels that were as tough to sharpened as some of the hardest rated super steels I’ve used.  

The point I’m making is the correlation between steel hardness and ease or difficulty to sharpen is not simple to state.  I can say based on my sharpening experience, with the Wicked Edge sharpeners, that I have not found any steels, no matter how high or low on the Rockwell “C” hardness scale that I could not sharpen with whetstones mounted on Wicked Edge paddles.  I have found some softer rated steels, on the hardness scale, that did suffer from edge failure while attempting to sharpen that knife with Wicked Edge diamond sharpening stones.

From my easy sharpening experiences and good results sharpening fairly hard, (HRc 64), high carbon, (non-stainless) steels with the W.E. diamond stones I thought that was the trend I’d experience with all high carbon, (non-stainless) steels.  After attempting a high carbon steel with an even a softer rating, I found that not to be the case.  No matter how fine grit the diamond stones, the sharpened edge fell off as quickly as I tried to sharpen it.  

Now I give a steel I have no prior experience with, one that is HRc 60 or softer, a first try, with W.E. diamond stones.  That’s because it’s a quicker, easier and simpler process sharpening with diamond stones then with whetstones.  If the steel doesn’t react to sharpening with the diamond stones as expected, I switch to a whetstones set, right away.

In general I sharpen knives made of harder steels, (HRc >60) with whetstones mounted on W.E. paddles.  I have not found any knife steels I cannot sharpen with whetstones.  I have found many knife steels, both hard and harder, I could not sharpen with diamond sharpening stones.  I would not attempt your Roselli with anything other then a whetstone. 

Sharpening that single bevel “scandi grind” or “chisel grind” knife is about sharpening technique and has nothing to do with the steel hardness.  

Marc
(MarcH's Rack-Its)

[John]

I thanks Marc. That answered a good portion of what I needed. I should have mentioned that I was also looking for a sharpening angle to achieve both a good and sharp edge

[Marc H]

From what you shared this’ll be your first time to sharpen this knife.  That said I prefer to match the factory bevel angle.  I like to believe that original edge profile was chosen to optimize the steel’s quality and character.

Use a sharpie marker to help you match the ground bevel’s angle.  The Wicked Edge is probably more precise then the original edge so you’ll apply a truer more even bevel down the entire knife’s length then the maker’s original.  With the single sided Scandi grind you’re only sharpening the one beveled knife side.  Generally, with the single sided Scandi grind or more correctly the chisel grind side is the bevel.  It’s one in the same at the bevel angle you’ll try to match. When you have that one side finished to the fine grit level and polish you choose to take it to, you’ll need to remove the remaining burr that’ll be produced and has flopped over on the flat unbeveled knfe back side.

You can do this by using your fine grit sharpening stones.  Do the sharpened bevel side as usual.  Do the flat knife side with out the guide rod, with the stone hand held, not on the guide rod for that side.  Pull the stone at as close to flat and vertical, 0.00º, against the knife’s back flat side’s apex.  You’re just wanting to contact the edge, just at the apex.  You’re intention is to remove just the burr from the flat back side without contacting the knife steel any where except just the apex.  Your producing almost no bevel or an unperceivable bevel, on the flat back side.  I try to use a light pressure edge leading stroke, that is pull the stone down and onto the very edge of the apex.  Try to alternate the hand held stone with the sharpening stone on the guide rod that was set to sharpen the ground side.  If this step is done cleanly it will result in a very sharp knife edge.

You may want to apply masking tape to the flat ground knife side.  This should help protect the steel from stray scratches during this last step that exposes the sharpened knife edge. If you can’t get the handheld stone as flat against the flat knife side as you need it, you may want to unclamp the knife and pull it across the stone as the stone lays flat on the table top.  If you choose to, you can finish the knife edge with strops.  One strop on the guide rod and the other hand held for the flat knife side.  Again you may need to unclamp the knife.  Then with the handheld knife pull it across the strop laying on the table top.

Marc
(MarcH's Rack-Its)

[tcmeyer]

I’ll agree with Marc on the ease of sharpening hard steels.  I just hardened a batch of four D2 blades using my propane-fired forge.  I used a digital thermometer and quenched using two 1″-thick aluminum plates.  Even after tempering in a 450 F oven for two 1-hour cycles, they’re still hard enough to cause a file to skate without biting.  Sharpening them was practically no different from the other knives I have.  I think that diamonds are so much harder than the HRc range of 58 – 67 that we typically see, that differences within that range are almost undetectable.  I think that toughness is, which is why some stainless steels seem to be more difficult than others.

[Author]

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