On Tue, 20 Mar 2018 10:59:44 +0700, John B.
wrote:
On Mon, 19 Mar 2018 19:48:03 -0700, Jeff Liebermann
wrote:
Incidentally, sharpening all my kitchen knives to an edge sharp enough
for shaving was NOT a good idea. I'm cutting myself quite often and
am slowly destroying my cutting boards and dishes. Paper plates no
longer work as my knives cut through the paper.
I don't do kitchen work but periodically my wife hands me a bunch of
kitchen knives and says "Sharpen them". Generally these are cheap
stainless knives and I've found that simply making a pass across a
grinding wheel on each side works pretty well. It produces a sharp
edge which is not perfectly smooth, more like a very fine tooth saw
which seems to cut better then a perfectly smooth blade.
Disclaimer: I am a beginner on knife making but am learning fast.
It depends one what and how you're using the knife to cut. If you
draw the knife as if you were sawing through the food, a rough edge is
quite superior to a razor sharp edge. However, if you're pushing your
way through the food with the knife, the razor edge works better.
What I did was buy about 15 assorted knives at a local outdoor flea
market and 10 more at a local thrift shop. I used these for practice
to learn how to sharpen them and how to modify the shape of the blade.
Most were stainless but I also found a few 1095 high carbon steel "Old
Hickory" knives.
https://www.knivesplus.com/OLD-HICKORY-KNIVES.HTML
I bought a Harbor Freight 1x30 belt sander and belt assortment from 80
grit to 800 grit:
https://www.harborfreight.com/power-tools/sanders/1-in-x-30-in-belt-sander-60543.html
an angle guide:
https://www.amazon.com/Knife-Sharpening-Angle-Guide-Sharpen/dp/B01HVXFP80
and a collection of whetstones:
https://www.ebay.com/itm/Japanese-Whetstone-Knife-Grit-1000-8000-Sharpener-Sharpening-Water-Stone-Stand/222660726466
I also setup a binocular microscope so I could see what I was doing to
the edge:
http://www.learnbydestroying.com/jeffl/pics/microscopes/Olympus%20SZ30/slides/SZ30-01.html
After a few frustrating failures, I determined that I could produce a
usable but rough edge with the belt sander, and then refine it to a
razor sharp edge with the water stones. The sanding might only take a
few minutes on the belt sander, but the water stone polishing can
easily take hours. I can easily see the difference with the
microscope.
I have 6" grinder, but I would not use it to sharpen knives. It takes
off too much metal too quickly to maintain control. When I tried it,
the result was a rather "wavy" edge. Even a belt sander takes off too
much metal if you use a rough (80 or 120 grit) belt. If you have a
belt sander, try starting with 120 grit to remove the dings and chips.
Then use increasingly finer belts until you get to 400 or 800 grit.
You can probably just quit there, or if you want a smooth edge, use a
succession of water stones (1000 to 3000) to improve on the edge.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558