Fillet knife sharpening

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Apr 18, 2011
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Okay, me and the grandson are puttin' a hurtin' on the trout! I tend to fillet them with 4" and 6" Rapala fillet knives. I'm sure there may be better, but these are quite satisfactory. It seems if I'm cleaning lots of fish a touch up or two during the process is in order. I'm good free-handing and have a Lansky kit, but due to the softer metal and flexible blades they aren't the best choice and time is of the essence. The quickest and easiest method seems to be a few strokes through the ubiquitous pocket "mini-sharpener" with two crossed ceramic rods. There are at least a half dozen manufacturers of these things (but info seems sketchy what the fixed angle is). I have several ( Lanky, Smith's, Rapala, one and two stage). Just eyeballing the things because I'm to lazy to dig out a protractor, I'm guessing they're all around 25 deg., which would probably be the best "one size fits all", prevent offering them in more than one angle option and keep picky sharpening folks like me from shunning them. Anybody know of one that has fixed angles of less than 20 deg.?
 
Okay, me and the grandson are puttin' a hurtin' on the trout! I tend to fillet them with 4" and 6" Rapala fillet knives. I'm sure there may be better, but these are quite satisfactory. It seems if I'm cleaning lots of fish a touch up or two during the process is in order. I'm good free-handing and have a Lansky kit, but due to the softer metal and flexible blades they aren't the best choice and time is of the essence. The quickest and easiest method seems to be a few strokes through the ubiquitous pocket "mini-sharpener" with two crossed ceramic rods. There are at least a half dozen manufacturers of these things (but info seems sketchy what the fixed angle is). I have several ( Lanky, Smith's, Rapala, one and two stage). Just eyeballing the things because I'm to lazy to dig out a protractor, I'm guessing they're all around 25 deg., which would probably be the best "one size fits all", prevent offering them in more than one angle option and keep picky sharpening folks like me from shunning them. Anybody know of one that has fixed angles of less than 20 deg.?



Haven't used this myself, but ran across this the other day... the "Smith's Adjustable Angle Pull-Thru Knife Sharpener"...

 
For a flexible fillet knife, I use a standard pull through sharpener. It gets a good enough edge for cleaning fish.
 
Does a fillet knife have to have a recurve?
If not, then i'd toss them and buy a new one which does not have a recurve.
Then I'd sharpen it with the Spyderco Sharpmaker or the 204M solo.
i doht like sharpening fillet knives. i get them super sharp but the blade recurve and the blade flexibility spoil the fun
 
I never liked sharpening fillet knives much, until I finally started doing so freehand with two hands on a bench stone. If the section of blade being worked is directly supported and controlled with a couple fingers of the off hand maintaining angle and pressure, then it gets more productive and simple. The control exerted directly behind the portion of edge being worked, by the 2nd hand, keeps the flex of the blade from being an issue. Also makes it much easier to do some heavier grinding this way.

Any method relying on a one-hand grip of the knife by the handle just never worked well for me, on flexible blades. And using a guided setup with the blade clamped is tedious and slow, as any heavy grinding near the tip will cause the blade to flex away from the stone. So everything has to be done with a very light touch, even if attempting a rebevel or any other heavy metal removal. Takes forever.

If you're lucky enough to have a factory edge with decent geometry and sharpness from the beginning, then a V-crock system (Sharpmaker, etc) could work well enough to keep it tuned up. The Sharpmaker will allow anything down to 15°/side (30° inclusive). And A.G. Russell markets a 'Field Sharpener' in a compact format with two pair of 4" rods, one pair being brown ceramic and the other being diamond. It also comes at a set angle of 15°/side (30° inclusive). The diamond rods in that set work pretty well for quicker grinding as well. I'd favor a setup like this over most any pull-through sharpener in general, if freehanding on a stone isn't in the picture.
 
Do note that the Sharpmaker can be cheated a little also to get a more acute angle - just hold the knife with the top of the spine a little tilted toward each stone as you use it. Probably easier for the freehand guys, but it does work.

And I agree definitely a must to use two hands - with the second supporting the blade near point of contact on the hone - when freehand sharpening a fillet knife, I should have noted that.
 
A grandson catching trout is a good problem to have. Yep, use both hands on the blade with a good flat stone. DM
 
Where did recurve come in? I've never seen a fillet knife with a recurve. I sharpen mine freehand and yes they can be a pain because they are so flexible.
I was thinking the same thing. Recurve on a filet knife? Never have seen one, and for good reason! But I think he meant "curve". The curve or belly of a knife never was a problem for me, but for sure thin flexible blades add a new challenging dimension for sharpening.
 
I have a small ceramic stick pull through that came with my filet knife. Works fine, and, more importantly does not eat up steel like carbide pull through. I also have a Smith combo with medium diamond stone and fine ceramic sticks.also works fine, but takes up more space, and I don't typically take it fishing.
 
Recurve on a filet knife? Never have seen one,
Zwilling Filiermesser [LINK]
2485_0.jpg

CUT_5_3763_20__S1.jpg
 
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Erm... that part doesn't ordinarily get sharpened... it's generally considered as sort of like the ricasso by everyone I know who sharpens fillet knives.
 
Regardless, those two photos are not examples of "recurve" knife blades, just ricassos that extend down. A recurve has a sort of "S" shape to the edge, where the nose drops down, usually (not always) to facilitate a chopping cut (weight toward the tip). Fillet knives don't need weight toward the tip because they aren't used to chop through a fish, rather to slice fillets off. Recurve blade:

vnwaPsg.jpg
 
Not me. Don't use it, so no need to sharpen it. I just let the sharpened main part of the blade fade off into that section.
 
Junk the pull-through. Most fillet knives use a fairly soft stainless steel that you can sharpen on practically any hone, though diamond (DMT Duosharps are good) would be my preference.
 
Junk the pull-through. Most fillet knives use a fairly soft stainless steel that you can sharpen on practically any hone, though diamond (DMT Duosharps are good) would be my preference.

There's a lot to be said for that.^ :thumbsup:

Nice thing about using a diamond hone on a soft stainless is, maintenance sharpening can be done at a very, very light touch. That'll help mitigate the flex issues with these blades. And the diamond hone will leave some very aggressive 'tooth' in the edge, which is ideal for a fillet knife.

I have one of the 4" Rapala flllet knives as mentioned in the OP. Shortly after I bought it, I did put it to a bench stone (India) to thin the edge geometry a bit. As for touch-up sharpening after the fact, I've just been testing it against a DMT 'Mini-Sharp' keychain hone in Fine grit (see vendor pic below). The two work well together, and the hone itself is about as pocketable as can be.

71twjbYYS8L._SX425_.jpg
 
Perhaps I am a bit old fashioned. I would not sharpen the edge(by removing metal), I would pull out a good sharpening steel and run the blade over that a few times and go back to filleting (8 seconds later).
 
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Any dmt stone is more than enough and they leave nice toothy edge,their folding pocket stone is what i use in field to touch any knife up,and it works great with shaving sharp but toothy edge.
 
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