Mid-tech edge retention

[rdmalak]

Hi all,

I was wondering if I'm the only having issues with edge retention on a Mid-tech? Before I use the knife it is very sharp to the touch, after every use it's quite dull to the touch. It takes at least a strop or a ceramic rod to bring it back. Then next time I use it I have the same issue. Am I expecting too much from a semi-custom knife of this price? My other gyutos (AS, Blue#2) go through way, way more before trips to the strop.

I appreciate any input on this. Thanks all

[chinacats]

Wire edge is most likely the culprit.

[EdipisReks]

Wire edge is most likely the culprit.

yup.

use a cork or the edge of your cutting board to remove the wire edge.

[rdmalak]

I have tried both of those methods. No dice.

[CrisAnderson27]

I have tried both of those methods. No dice.

Have you ever sharpened a knife with this steel? I have no experience with it, but it could be that whatever methods you're using are forming a 'micro burr' for want of a better word.

Inspect the edge with some magnification perhaps, see if you can see a non-tactile wire edge.

If not, I'd maybe suggest contacting the maker? That would have been my first suggestion, but maybe you already went that route.

[EdipisReks]

what is the knife? "mid-tech" doesn't actually mean anything, particularly. despite that, user error is almost certainly the issue.

[CrisAnderson27]

^^^ I assumed it was one of Pierre's....my bad there.

[Justin0505]

As others have mentioned, it could be user error and you're not actually removing all of the bur. Some steels / burs are kinda tricky and you really have to hone them down and then run them through soft wood, hard felt, or something with a bit more "grab" then cork.

However,
On some blades made out of tough steel with a chip-resistant temper, I have noticed what seems like a fatigued, not wire, edge. This seems happen to edges that have been maintained for a long time with just rods and strops. So, the steel at the edge has basically just been deformed and realigned time and time again without actually removing any/ much of the steel. It will feel sharp, look fine, and not show any sign of a bur when pulled through cork or examined under magnification, but it will deform back out of alignment very quickly when used. It's just been bent back and forth too many times and needs to be removed.

How many times have you fully sharpened it (taken it though a full progression on the stones)?
Another other thing that can happen with knives that are ground and sharpened too quickly using a high-speed belt or wheel is that the thin metal at the edge heats up too hot and the temper is messed up. This can usually be corrected / improved after a few sharpening and thinning sessions as you remove the damaged steel near the edge and work your way up into what was originally slightly thicker material behind the edge which was not weakened in the same way from the grinding heat.

A third possible cause is that your edge angle is just too acute for the steel and it just can't support it for long.

In the ended it could be any 1 or a combo of these things. But the solution is the same no matter what: give it a good sharpening, not just a stop / hone.
Take it to your coarsest stone and take off a bit more steel than you normally would. Set a nice fresh primary bevel and then work up though your stone progression. Created what you know to be is a clean, fresh edge with no bur, and with a reasonable angle (sometime in the range of 25-30deg as the sum of both sides).

Alternately, if you don't trust your own skill, you could take it to a pro (like Pierre, I dont know anyone else in Canuck-land) and request that they do the sharpening (with waterstones) described above. That way you take yourself out of the equation.

[rdmalak]

First off, yes it is a Rodrigue mid-tech. My fault for not mentioning this already. So this, to me, means the steel is not an issue but I have never had a knife made of this steel before. It should be able to handle a pretty acute angle.

The edge it came with was not great so I brought it to 1000 grit and started again. Brought it up to 4000 only.

I have not used it much due to this issue so it has not been over used on the strop or rod.

I will try and sharpen it again and report back. I was hoping that this knife was going to be as easy to maintain as my other ones but maybe I was incorrect.

[CrisAnderson27]

What did Pierre say?