Need tips: Rebated edge sharpening

O

oldscrimmer

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Nov 23, 2007
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I've got a couple of CRKT folders with rebated edges and am having a bit of trouble choosing the right equipment to get a scary sharp edge on them. Anyone have any tips on equipment or technique? Round seems to work best....whatcha think?
 
A "rebated" knife is one where they give you some of your money back as a form of discount. I assume you meant to say "recurved" where part of the blade edge is curved in towards the spine of the blade and hence hard to sharpen with a flat hone. I use an Ultimate Edge oval diamond steel for most of the work on my recurved blades and then a ceramic rod sharpener for the last little edge polishing.
http://www.theultimateedge.com/sharp10w.html
http://www.spitjack.com/Merchant2/graphics/00000001/idahone_cs-24.jpg

If you don't have a lot of material to remove on your blade you could just use a round rod ceramic system like the Idahone in my link. You can likewise use the triangular Spyderco Sharpmaker. The edges and the narrow flats will work on the recurve and it can also do a superior job of sharpening straight edge knives and serrated knives.
http://www.1sks.com/images/spyderco/sc-204mf-modes.jpg
 
Thanks! I'm headed in the right direction, I've got ceramics and round diamond rods...will take your advice using them.

In response to "rebate" I understand the definition, however, I reload for my firearms and a rebated rim is one which is somewhere between a rimmed and rimless. IE: something taken away from the original, in this case material. I'll use recurved in reference to knives, it's a clearer definition anyway.
 
I thought that a rebated rim was one step beyond rimless. It is one where the rim is smaller in diameter than the body of the case. It allows you to use the same bolt head and extractor for a .50 caliber case that you would use on a normal rimless .44 case. I didn't see how it described a knife blade. The "recurve" usage is common. I also think that convex edge describes how these work. Incurved or indented might also be descriptive.
 
By the way, Darrel Ralph considers himself an innovator of modern recurved folder designs. He mentions a milestone in 1993 where he kicked this off. Down near the bottom of this webpage he shows some serious recurve design work. He even has a recurved butterfly knife.
http://www.darrelralph.com/DDR-ACH-WEB1.htm
 
I've always admired the history of the kukri and it's usage and it seems to follow that a recurved type edge would be a great field tool for field dressing and such. I've yet to try it on field work, but the design looked like it might give a bit of a bite that a straight edge wouldn't have. I guess we'll see! Appreciate the link, I'll look it over. Your responses have been helpful.

I worked on a Mini My Tighe in between forum responses, and found that the round definitly is the route to go, but I also found that on my particular piece the bevels were not the same grind on either side. One was narrower than the other. I got a sharp edge, but wasn't happy with the way it looked when you roll the knife from side to side. Also, I had to watch the tip, not to round it as it leaves the cutting surface of the rod. Guess it'll just take time to work the bevels back to even.
 
Oh, you are correct about the rebated rim, I was having a senior moment. It is smaller than the case head. Anyway, recurve it'll be for knife discussion. Thanks!
 
It is just a convention to call diamond coated rods that you use while holding in your hand "steels". They look something like a steel and you stroke edges with them much like a steel, but they are in truth just rod-shaped hones. They are rather aggressive hones at that. There are quite a few different brands of these diamond "steels" these days. I own several and I also have a few ceramic "steels" that are likewise misnamed. Here's a link to a pile of varieties. http://www.kendelcutlery.com/sharpeners-and-steels.html
 
Sorry, I still don't have all the lingo down... when you say they are aggressive hones, does that mean that they actually remove material, rather than just straightening the edge? I guess I was trying to ask whether diamond coated "steels" can actually sharpen a blade.
 
When I say a device is a "hone" I mean that it is designed to sharpen an edge by abrasion. When I say a device is an "aggressive hone" I mean that it removes metal rather fast. Diamond is not only a hard abrasive it is also a sharp abrasive. Diamond grit cuts faster than most other grit of the same size. For example I used a 600 grit diamond "steel" to drastically reduce the edge angle on a D2 alloy Camillus EDC model knife. This also had a recurved edge. I did the same thing to a Camillus EDC with a 154CM alloy blade. Both of those alloys are difficult to hone. To do this kind of reprofiling work I would normally use a coarse 120 or 220 grit silicon carbide hone. I was able to do the same work (with a little extra time) using a 600 grit diamond hone. You don't straighten an edge with a diamond steel, instead you grind the edge to a new shape, just like with any other hone. It should not really be called a "steel" at all.
 
So does that mean that a diamond steel is not something I should be using each time I use my chef's knife (Wusthof)? I guess that's why my knife hasn't needed to be sharpened in the 5+ years I've had it... because it WAS being sharpened!?! By using it each time, am I removing more metal than necessary?
 
While you have been removing more material than necessary it isn't a significant problem unless your knife has been getting small or misshapened.
 
Hope this thread has given DainBramage some help too! Once Jeff and I thoroughly discussed "rebate" and "recurve", I got my terminology correct, we began to learn something. I worked on my recurved blade some yesterday with a diamond impregnated rod and got a decent edge. However, I found that the grinds on the bevels were not the same (this was a new knife) so I had to do additional work.

I've used the same diamond rod on one of my old Chicago Cutlery kitchen knives for many years now and though it's a tad narrower than it once was, it's still cutting wonderfully, and the blade is still shaped properly. That comes from doing a full stroke bottom to top/top to bottom, each time...removing the same minute amount of steel with each stroke keeps the blade shape. Thanks Jeff!
 
Jeff Clark said:
While you have been removing more material than necessary it isn't a significant problem unless your knife has been getting small or misshapened.
Click to expand...

Yeah, I guess then I would have to look at some of that Japanese steel, huh? :o

Thanks for the great answers as well as for putting up with all of my n00bie questions!!
 
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