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charlie b

wrote:

Just bought the wife a nice set of Kitchen knives for Christmas,
and had heard the advise to hand wash them only, I suppose
because the granular dishwasher detergent might dull them.

Truth or wives tale??????

I'm going with Truth - at least for good knives.

Carbon steel will take a better edge than SS or HSS.
Won't hold it as long, but it can be made sharper.

Sharp carbon steel edges don't dull faster if you take
care of them. When they "dull" it's because the edge
has been rolled - think Cabinet Scraper. If you use
a "steel" on them you straighten the edge back up.
Think of the "steel" as a cabinet scraper burnisher.
If you don't "steel" the edge when needed, the rolled
edge breaks off. THEN you've actually dulled the edge
and you have to sharpen it - ie - selectively remove
metal.

Now if you've ever "burned" an edge while sharpening,
you know that by the time you can see "color" it's
too late. You actually lost the temper on the edge
BEFORE the temper killing heat's color indicator was
visible. Remember, at the actual cutting edge there's
not much metal so it heats up fast.

Heat is the enemy of a really sharp edge on carbon steel.

Most new dishwashers have a water heater in the
inlet path that kicks it up to 160 degrees or more
AND some have heating elements to dry the dishes
(and the chemicals that are in "hard" water). Doesn't
take a lot of heat to affect the temper of a fine
edge on a carbon steel knife, or chisel or plane iron.

Now add a fairly concentrated base (soap as opposed
to an acid) and you're begging for a chemical reaction
with the carbon steel - and one that ain't good for a
fine cutting edge.

Just for fun, put your next razor blade in the dishwasher,
run through it's cycles and THEN shave with it.

Oh, BTW, cutting edges hitting anything metal isn't
good for them either - even just a little contact is
BAD.

charlie b

occassional user and caretaker of some Chicago
Cutlery carbon steel knives - with wood handles,
not polished, not coated with poly or plastic or
varnish, just oiled when they look like they need \
it.