Trouble sharpening Henckels knives
I have a full set of Henckels (mostly five-star). They are 20-25 years old with light daily use.
I simply cannot get and keep an edge on them all of a sudden, even using the techniques I have always used. I am an advanced hobbyist woodworker and can put an edge on a plane blade that allows me to make a wood shaving I can see through. I have a full set of oil and water stones. I have even paid (ughhh) to have the knives sharpened -- and within a day or two: dead.
My regular routine is to set a primary edge of about 20 degrees and a compound edge of 25-30 degrees. The knives are finished off with a 6000 grit Japanese water stone.
I use a bamboo cutting board. The knives have never seen the inside of a dishwasher.
So....I hear from Williams and Sonoma that knives this old can lose their ability to hold an edge. I'm not sure I buy that, but my experience has me spooked.
Anyone else experience this?
I also have Henkles knives about 25+ years old - they were called Four Star when I bought them IIRC. They've been my only knives over that period and have gotten a good bit of use. I also am having trouble keping them sharp now. My technique isn't anywhere as technical as yours...I didn't do anything but the steel until about 8 years ago, and now take them to the little local sewing machine shop every year (if i'm lucky) and just hone on the Henkles steel in between. This served me well until lately - now it seems they just won't hold an edge. I really don't want to replace them for "sentimental" and economic reasons, but I need good knives!! What to do?
Not sure what you mean. "Thinned?" And by "behind the primary" do you mean the secondary bevel or the flat of the blade. I can't imagine the latter has an effect.
I have tried primary bevel only (which is what most home sharpeners and shop sharpening is), but also done primary/secondary bevel.
I think scubadoo is right about thinning.
Rather than have all the flats reground (difficult and expensive) or having a tall secondary bevel ground in (a little unsightly), you might want to take/send the blades to a pro sharpener who does good rolled (convex) edges (e.g., Bob Tate, Bob Kramer's understudy). I think this would thin out the blades enough that you can then have a few additional years of your own fixed-angle resharpening. It'd also give you an idea of how good a rolled edge can be.
I contacted Bob and will probably go that route. By the way, I mentioned the rolled (convex) edge and he did not seem to know what I was talking about. Maybe that is not his technique? Anyway, he seems to have great references, so I'll go that route for now and use a ceramic steel. Still disappointed I could not get a good edge on these knives, since I was always able to do so before. Maybe I'll find out something after Bob works on them.
From what I know, ancient swords dug up thousands years ago can be sharpened, so I really do not buy the idea that an 2-30 steel cannot be sharpened. I am really amazed that people come up with stuffs like this. Seriously, I cannot even dream up stuffs like this. In all honesty, people from Williams and Sonoma aren't exactly knife experts.
I think scubadoo's theory can be correct. Through some of what you said, does not seem to match up. For example, you wrote "I have even paid (ughhh) to have the knives sharpened -- and within a day or two: dead." So you are saying that they can be sharpened, but the edge does not last more than a few days. I would think if the blade is thick behind the primary bevel, then it just does not feel as sharp in day 1 and it should not have the "sudden deterioration" experience you had.
Anyway, to thin out the blade can be time consuming. A more practical method is to put a back-bevel and primary bevel as scubadoo has suggested. For example, put a 15o back bevel and then put the 20o primary bevel. Basically, the following:
The older knives might have been case hardened, such that the hardening reached the center of the metal in the thinner parts, but not quite in the thicker parts of the knife. If that's the case, you'll never get them to stay sharp if you've removed enough metal to move the edge close enough to the spine to miss the hardening.