sharpening fillet knife

[tomboyd]

I set my angle at 15 and still can not get a sharp edge, it's a gerber and i graded the stone to fine, is it me or are these really hard to sharpen

[Herman Trivilino]

Examine the edge with a magnifier. Wipe the knife on a rag to see if there's a burr that snags fibers of the rag.

Try preparing the grindstone coarse, but keep your eye on the bevel to see if it reaches the cutting edge.

[grepper]

As far as I can find out as of  2009, some dude posted that an email reply from Gerber that stated:
------
***NOTE*** January 2006 – December 2007 this steel type was comprised of Sandvik 12C27 SS.

***NOTE*** January 2008 – April 2008 the steel type was temporarily changed from the Sandvik 12C27 SS to 440A U.S. SS.

***NOTE*** May 2008 – current: Production had not resumed with the Sandvik 12C27 SS due to complications with material availability, but switched to a more closely matching steel, the US 420HC.
-----

In general:

12C27 SS:  HRC 58-60
420HC: HRC 58

Either way, it's pretty hard steel. 

Both are good quality steel and chipping probably won't be an issue.

You mention you have the stone graded to fine.  Maybe that is the issue.

I've found that sometimes not using a coarse enough abrasive can be the problem.  Knives that would not get sharp with a fine abrasive sharpened quickly with a more coarse abrasive.  So, I agree with Herman.  As he mentioned, if you are getting good contact with the wheel and getting a burr and it still won't get sharp, try a coarser stone.  This could be necessary especially if you are putting a more acute bevel than what was there before.  You could just be sharpening the edge of the bevel and never reforming a sharp edge.

I've learned that if you don't spend enough time using a coarse enough abrasive, you can spend forever trying to get an edge.  Just take it easy at first and check the bevel as you are going along.  I know the inclination towards not removing more steel than necessary, so just check as you are sharpening to see what's happening.  It might just solve the problem.

[Herman Trivilino]

As he mentioned, if you are getting good contact with the wheel and getting a burr and it still won't get sharp, try a coarser stone.

If you are not getting a burr, try the coarser stone.

[tomboyd]

could it be my honing abilities need improving i think thats one of my problems

[grepper]

Sorry, didn't mean to misquote you there Herman. .

Nonetheless, I've seen it a number of times, where I had difficulty getting an edge sharp because of a too fine abrasive.  Might help.

You might be right Tom, about honing.  If you leave a burr on the edge, even a sharp edge will seem dull.  A quick and dirty check for that other than feeling it, seeing it visually, or if it catches on paper towel or a soft rag, is to gently cut some soft wood on the corner with the grain.  It will usually tear off a burr.  If it's suddenly sharper, then you know it's a honing issue and can give it quick resharpen and then spend some more time honing.

Just from my experience, it's generally one of two things:  Either you are not cutting the edge, or a burr is left on the edge.

Of course that is assuming you don't have junk for steel, but being a Gerber I doubt that is the case.

[grepper]

Two examples of when I was actually surprised at needing to use a more coarse abrasive happened when I was given a set of Old Homestead cutlery and a set of old Case XXX kitchen knives to sharpen. 

I labored away on the Tormek to get them sharp and it was taking forever with little results.  I started to wonder what I was doing wrong.  It turned out that whatever steel those were using was extremely hard.  I think I remember posting about the Case knives here.  If memory serves me correctly, I researched it and with great difficulty found that the steel used was HRC 60.  That stuff is really hard!

At first I thought I was doing something wrong.  It was frustrating.  I made sure I was doing everything right and cutting down to the edge, but the going was very slow.

Out of frustration I took it to the belt grinder and threw on something like an 80 grit Zirconia belt.  Usually the sharp, aggressive Zirc belts hog off material, but I was surprised that I could apply a lot of pressure and it didn't remove too much steel. 

What did happen though was that I was able to get a sharp edge in a short period of time.  I was putting so much pressure on the belt that I had to be aware of heat, but if you are aware of it it's not a problem.

The point being, that what I experienced, is that really hard steel can be difficult to sharpen on the Tormek, requiring grading the stone very often to keep it cutting. 

Sadly I'm not a woodworker, but I've seen a number of posts from folks expressing difficulty sharpening hardened steel planer blades.  I suspect something similar is happening.  Maybe the solution is that the stone must be graded to coarse very often and a lot of pressure applied. 

Tom, if you happen to have one of the Gerber blades that is around HRC 60, I can commiserate that getting them sharp may be time consuming.  I don't know if that is what is going on, but if that's it, they are just difficult to sharpen.  Just guessing!

[grepper]

Just curious, Tom.  Did you ever get that Gerber sharpened to your satisfaction? 

[tomboyd]

cuts like butter, just took a long time to get the right burr

[grepper]

Thanks Tom.  Glad you got it sharp.   I'm sure sooner or later I'm sure someone else will have the question.  Your thread may prove helpful.

[grepper]

I was doing some general reading out there in Netland and happened to stumble on an article where the author was talking about sharpening with paper wheels, and he happened to mention:

"The most difficult knives I ever tried to sharpen was an old set of Gerber kitchen knives. They were so hard that natural stones hardly touched them. Diamonds would grind them, but I don't have a diamond stone fine enough for a shaving edge. Paper wheels is the only system that has ever brought these knives to a razor edge."

So, Tom, looks like you are not alone, and you are lucky!  Apparently you have one of the Gerbers that were made when they were using particularly hard steel.  Difficult to sharpen, but I bet it holds an edge well!

From this article:
http://sharpeningmadeeasy.com/knives2.htm#power

[Herman Trivilino]

That free hand technique he describes with the paper wheels is identical to the free hand technique on a Tormek. My frustration with it is what led me to make a homemade jig to keep the blade at a constant angle.

[grepper]

I have the paper wheel system that he uses.  I have not used it much, and they advise that it will be very aggressive before the grit on the wheel gets worn in.  They are correct about that.  It's 180 grit, and cuts like crazy.  It also heats up very quickly.  It seems you don't want to spend more than a second, or less, or so over the length of the blade, and even then it gets pretty warm.  A quick, smooth motion across the wheel is necessary.  Like a Zen artist using very thin ink on rice paper.

I do have to say, that after some practice I was able to get a blade extremely sharp in about 30 seconds.  It works as advertised, even on really hard steel.  And it was really sharp!  But, the thing is spinning @ 3,000 rpm and a little freaky to use compared to the Tormek.

It's also very easy to trash the edge, and/or waste a lot of strokes and steel trying to match the bevel angle with each pass.  Something I'm not very accomplished at.  It would require a along time and a lot of practice before I used it on a knife that I cared about.

I used it on a hard steel blade that I was having difficulty sharpening on the Tormek.  To my surprise I got it razor sharp in less than a minute.  The bevel was not even, and when I looked at it closely the angle changed, and had micro bevels over then entire length of the blade.  My lack of skill hand sharpening resulted in a far less then professional looking result. I have to admit it was extremely sharp, very quickly, but predictable, even bevel?  Not.  To achieve professional results like you can easily do with the Tormek would, at least for me, require a whole lot of practice.

I'm not fully convinced that if you carefully checked the bevel produced by even someone who was very good and experienced at freehand sharpening, that there would not be micro beveling.  I just doubt it's possible to freehand that accurately. 

Definitely not my go to sharpening system.  But it did teach me one thing:  If you are having a difficult time getting something sharp, don't be afraid to spend more time with a coarse grit. 

[tomboyd]

going fishing in the a.m. i'll let you know if it holds an edge.     I hope

[tomboyd]

good day fishing and knife was better then new, very pleased