Concave carving knife

[unnervingfalcon]

I haven't owned this Tormek T7 for very long but I was asked to sharpen a partial concave carving knife.  This was totally frustrating.  I knew this was going to be a problem and had asked this at a seminar but was just told you can do it.  Never thought it was possible but I attempted anyway. 

Here is what I did.  I realized before I tried that I couldn't do the sharpening the traditional way because of this concave issue.  The concave could only be sharpened at the edge of the stone.  If I did this it would take a chunk out of the blade and would most likely make knife jump during the process.  This would be extremely dangerous.  The only safe way is to go with the stone and not against it.  So I put the universal support on the other side.  This way I could use the edge safely.  It did work and yes the burr wasn't great at all.  Honing wheel didn't really do a thing.  So I had to take a mini stone the size of my thumb and go against the edge.

P.S.  I hate these concave knives with a passion.  Here is a photo of a very similar knife but mine was more concave near handle.

http://ancientpoint.com/imgs/a/f/s/y/u/fm_whiting_sterling_silver_handle_14__roast_carving_knife_flower__scroll_fws33_1_lgw.jpg

[Herman Trivilino]

I've heard reports of people rounding over one edge of their grindstone so they could sharpen a concave blade.  I can't imagine myself ever doing that.

I had a cheap paring knife with a concave blade that my wife picked up somewhere.  When it got dull I just reshaped it so the edge was no longer concave.

The knife shown in that photo looks to me like it originally had a straight edge on it and it became concave from it being sharpened incorrectly.  I'd be tempted to straighten the edge on it if it were mine.

[jeffs55]

For a knife like that you really need two counter rotating grinding wheels so that you can place the blade at the point where the wheels meet. Master Grade makes a good device that is relatively cheap that uses this function. You could of course upgrade to a F Dick sharpener but the cost will make you sick. Either one is too much an investment unless you are going to be paid for your service.

[Ken S]

I have a knife which looks a bit like that.  I'm not sure if it started concave or was just poorly sharpened over time.

I think this is a one time problem which calls for a low tech solution (unless one plans to make a career of sharpening concave knives).  I would use a round dowel with abrasive paper.  I have used the same solution (with a smaller dowel) successfully in sharpening my serrated bread knife.

Working carefully, the entire operation should not require more than a few minutes.

By the way, I think making a radius on the inner face of the grinding wheel is a clever idea.

Ken