Between the water agitation and the abrasiveness of the DW detergent, a dishwasher call dull good edges.

I'm sure that a lot of people will pipe up and say that they've never had a problem, but I wouldn't chance it.

Other reasons why to not wash knives in the dishwasher, such as loosening handles, wood handles, cutting the coated racks wires and hastening rusting in the DW, etc,

But I've always heard that dishwashers will dull good blades.

Well, this explains why my knives don't seem to sharpen up like they used to!

Dishwasher detergents are not abrasive. I wash my sterling and they show no signs of being abraded.
What dulls a good knife in the dishwasher is banging against other items, and excess heat which can detemper the edge.
I put a lot of my knives in the dishwasher....my dishwwasher, a Jenn Aire....has a little place to firmly hold a knife to wash it without banging it around.
Perhaps your German knife was sharpened in such a way as to cause the blade to lose it's temper.
Linda C

What method/tool did he use to try to sharpen the blade? Something about how the story was presented makes me wonder if all he did is run the knife down a steel. If so, that'll never sharpen a dull knife; it only realigns a sharp knife.

Older knives can also get out of "straight" and that is why a butcher's steel is used, not to sharpen it but to fix the micro-serrations, or to "hone it" with this tool, also known as a honing steel. But it has to have a sharp edge first.

Your knife can be sharpened by a professional. It will be ground (using a whetstone) to form a new edge, then honed (with a steel), and then stropped on special leather to polish it. As it dulls you should be able to just use a fine whetstone minimally to resharpen it.

It is safer to have a sharp knife than a dull one because you will exert more effort with a dull one and therefore allow more slippage of the thing you are trying to cut and more injuries occur because of that misplaced force, also known as oops or ouch. A really sharp knife slices like a hot table knife through butter and if it is sharpened correctly it will cut though the skin of a tomato without tearing and without any exertion. It also results in less fatigue when doing large batches of something, like fruit for jam, or a dozen whole chickens to be portioned.

When my then-fiance first sharpened my knives, the point of them always managed to nick me, so from then on he purposely dulls the very point for me. He checks the sharpness on his fingernail. When perfect it will leave a tiny fine groove without any effort.

A good knife should be washed by hand (never, ever soaked in water nor in the dishwasher) immediately after use, and dried with a towel. Ask yourself, "Is this knife really that dirty that it has to be washed with high temps and harsh DW chemicals?" I find that a magnetic strip is the safest place for them, but a good wooden block is next best. Any drawer is the worst possible place for sharp tools unless there is a knife block to hold them safely there.

Nancy

I have a set of Henckels that the butcher at our local Big Y sharpened for free, and did a very good job. Perhaps you could have a butcher take a look at it.

All knives can be sharpened, including a plastic knife. The question is how long a knife can hold the edge.

The harder the steel, the longer it can hold a sharp edge, also the more difficult it is to be sharpened.

Depending on the material, typically the making of a knife is first heat treat to red hot (1,500F +) then harden by quenching. After that it is tempered at around 400F for a few hours.

No, a dishwasher CANNOT de-temper a knife. It requires more then 400 F to de-temper a knife.

There are many reasons why one can have problems sharpening a knife.

1. Lack of patience - you need a lot of time to sharpen a good knife.
2. Lack of good sharpening stone (s) - a range of good sharpening stones from coarse to fine grid.
3. Incorrect sharpening angles - each knife has specific sharpening angles.

For those of you who are not in the position to do your own sharpening, a sharpening machine can be very helpful, but don't use a machine for those expensive knives.

dcarch

I get my knives professionaly sharpened for $3 each. It's not expensive, and they can do wonders with any kind of knife.

I've used whetstones, and if you have a good knack for keeping the angle consistent you'll do okay. The best sharpening method I've found, though, is to use a paper wheel system. In this you have two cardboard composite wheels which replace the carborundum wheels on a bench grinder. On one of the wheels you place wax, then grit; on the other you use jeweler's rouge. You shape the edge on the grit wheel ("raise a wire edge", as the sharpening gurus would say) then hone it on the rouge wheel. It can get even stubborn stainless knives sharp in a few minutes, and an old fashioned carbon steel knife gets razor sharp with little effort. The only drawback to this system is that you need space in your workshop or garage for a dedicated bench grinder.

If you want an exhaustive resource on sharpening, follow the link to Steve Bottorf's site. He also sells paper wheels and describes how to use them. He also reviews various sharpening devices, from kitchen drawer gadgets to professional sharpening machines. He has written a book on the subject, but the web site has a lot of that info for free.

As far as dishwashers go, I don't let my knives in them, except for some cheapo plastic handled parers. Certainly no good knives go in there.

Here is a link that might be useful: sharpening made easy

He used a whetstone placed on a towel on the counter. I didn't stand there watching him long enough to see if he used a steel in addition to the stone. Maybe I need new stones. I can't even tell which side is the fine grain and which is the coarse grain any more, they've darkened so much. I have one hand held stone and one rectangular one, which is the one he used.

Free? $3.00? I had no idea one could get their knives sharpened so cheaply. I have no idea where to go to have it done. I guess I can Google it.

I do the worst storage method - in a drawer. I'll look into getting a magnet. I've looked at blocks, but you have to get one with slits the same size as the blades. I haven't found one that fits my cheaper Henckel knives.

Thanks for the input.

Sally

Sally, I've used the one at the link. It's very strong and can hold even large chef's knives. This is a 20" model; they also have a 15" model.

I'm right handed. I keep all the edges pointed to the left, so when I grab a knife I just twist it off with the edge pulling off the magnetic strip first.

Here is a link that might be useful: magnetic knife holder

That looks like a great solution to my knife storage problem. Thanks.

Sally

If the knife is very badly dulled and you only have a fine grit stone, it can be hard to get an edge.

I'd get that knife professionally sharpened, then maintain it with the steel and stone. When you're here in July (we're still doing that, right? I will revive the original thread to see if other CF'ers will be around) I'll show you.

Don't have it professionally sharpened more than a couple times a year. I suspect some places use a grinding wheel which takes off too much metal and will shorten the life of your knife if done frequently.

Often professional sharpening is around $1/foot of blade. Call your local kitchen store (Sur La Table or the like) if you have trouble finding someone.

John, I think the price is more like $1 per inch of blade, not per foot.

For hanging knives, alternatively:

1. Get Rare Earth Neodymium magnets on eBay. Epoxy or Hot Glue the magnets under the cabinets somewhere convenient. These magnets are very powerful and can hang your knives by the tips alone. This will save space and the knives will dry better. I will show photo later.

2. If you have old defunct PC hard drives, open them up and you will find inside two kidney-shaped powerful Rare Earth Neodymium magnets for you to use.

dcarch

Our own Ann makes and sells magnetic knife holders.
I think she has a link on her page....if not email me and I'll send it to you.
Linda C

If you are in a small town like I am, it's impossible to get the knives professionally sharpened. When we had a Hancock's fabric store, a guy would come around twice a year to sharpen knives charging $3 or $4/per knife. The store was shutdown and now nothing. I've talked with friends in restaurants, and they say they send theirs out and it takes 3-4 weeks to get them done. They would seen mine too, but I don't have enough knives to tide me over.

We have Sur La Table, Williams Sonoma, and Bed Bath & Beyond, so one of them should be able to point me in the right direction. (And yes, John, We're heading up there the week of July 22. I'm really looking forward to it!)

Dcarch, you are always so full of useful information. I don't have an old PC lying around, but if I come across one sometime, I'll look inside of it to see what I find.

Sally

I know Peppi goes some place in Chicago and gets her knives sharpened, even here in my small town they do it at the hardware store.

Elery sharpens mine now, Dad used to do it. Of course, Dad also sharpened the hoes, my limb loppers, the lawnmower blades, scissors, everything. I'm not nearly as good at it as he was. Just one more thing I miss. Sigh.

I have an insert in a drawer made to hold my knives, so it doesn't need to have a slot the size of the knife blade. The same drawer holds a large pull out wooden chopping block and it's right next to the stove. The chopping block pulls all the way out for easy cleaning but it's heavy so I don't chop on it and then pick it up to try to scrape the chopped food into a pan, etc.

And I never put my knives in the dishwasher, at least not the good ones. I have an amazing Wusthof tomato knife that Nancy and Kim got me as a wedding gift, a nice Santuko that originally belonged to Elery, a KitchenAid chef's knife that feels good in my hand. Those get washed by hand. The 40 year old Ginsu and the Chicago Cutlery serrated steak knives with metal handles? Those I put in the dishwasher...

Annie

Sally, check your mail, I sent you some info.

Speaking of knife holders, I have the magnetic strip (thanks to Jessie); I also have this block which I LOVE!

Here is a link that might be useful: Knife Block

sushipup: John, I think the price is more like $1 per inch of blade, not per foot.

You're right - sorry, I just spaced out.

Here is a picture of how powerful rare earth magnets are. They can hold up my knives by the tips only, including a very heavy thick cleaver. This saves me space and the knives dries quickly.

As I said, the most important skill in sharpeniong a knife is to keep the correct sharpening angle. Too acute an angle, the edge never gets sharpen. Too blunt the angle the edge gets messed up.

Let me share with you a tip on how to sharpen any knife and keep the correct angle.

You mark the edge with a marker and lightly grind the knife on the stone at a slightly acute angle and check the mark with a magnefying glass to see how close you get the the edge. You increase the angle gradully until you get to the edge. That would be the exact angle you need to keep the knife on the sharpening stone.

dcarch

That knife storage is too cool! If you bump one knife while reaching for another, do they fall down?

John, no they don't fall down. I do have to be careful with the big cleaver because it is very heavy, bone crashing heavy.

dcarch

Thanks, Peppi!

Mustangs, that knife holder looks like a space saver.

I'm being dense - I'm not sure what the mark is supposed to look like when you get to the edge. Is it supposed to be barely worn away?

That's quite a knife collection you have there, Dcarch!

Sally

Sally, it is a real space saver and it blends into my granite backslash nicely (I have the black). You can fit a number of knives and different sizes as it doesn't have predetermined slots.

DC, indeed, those are some serious magnets!

It is safer to have a sharp knife than a dull one because you will exert more effort with a dull one

This is a popular and oft repeated maxim, but I have two cuts on my fingers this week from my razor sharp knives that my dull knives never produce.
I work often with razor blades and cutting instruments (new x-acto knives and the like) and have a healthy respect for a sharp blade.
But in my entire life, a dull blade had never knicked my skin, or as often implied, cut off a finger.
I like a sharp tomato slicin' blade as the rest of you, so just saying.

Sally, to sharpen a knife correctly, you need to sharpen it at the same angle every time.

Picture #1 shows sharpening at a slightly acute angle.

Picture #2 shows sharpening at a less acute angle, the mark is worn off closer to the edge.

Picture #3 shows sharpening at an angle until the mark is worn all the way to the edge. That will be the exact angle you need to hold the knife to sharpen it.

Let me know if you still have more questions.

dcarch

Thanks, Dcarch. That's very helpful.

This whole thread has been very informative. Thanks, everyone.

Sally