Recent posts

#91

General Tormek Questions / Re: Capacitor Impedance for To...

Last post by Herman Trivilino - July 26, 2025, 04:59:19 PM

Sorry, Ken, to have to use a formula. The impedance, in ohms, of a capacitor is given by 1/(2*pi*f*C), where f is the frequency in hertz, and C is the capacitance in farads. So, for the T8 the capacitance is 25 microfarads, or 0.000 025 farads. If you're in North America the frequency is 60 hertz (in Europe it would be 50 hertz). That works out to about 210 ohms.

So, loosely speaking, the capacitor offers a resistance to the flow of electricity of about 210 ohms.

#92

General Tormek Questions / Re: Capacitor Impedance for To...

Last post by Herman Trivilino - July 26, 2025, 04:43:12 PM

Impedance covering capacitance+inductance+resistance (Z=R+jLw+1/jCw), OP was correct...

Impedance is measured in ohms, capacitance is measure in farads. OP wanted to know the number of farads, so he was looking for capacitance, not impedance.

#93

Knife Sharpening / Re: Beyond Basic BESS

Last post by Royale - July 26, 2025, 04:12:51 PM

Edge retention is still something that is somewhat of a mystery to me.  I have tried 600 grit and very little honing to highly polished.  Neither seem to be superior in terms of edge retention.  That is, retaining a 70 edge on the BESS.
After use, all steels I have sharpened lose that super sharpness in the first couple uses.  Some steels jump to a 140, some to 240 on everything but the softest foods.
They all seem to lose that eye popping sharpness very quickly.
I only have my tests to gauge this on.  I haven't seen any tests for real world usage to measure how fast the edge degrades.  I suppose CARTA tests do show the degradation but usually they demonstrate how long the usable edge lasts, not how long they stay ultra sharp.
Once again, how sharp you need/want to keep your tools/knife is very personal.  I had a carpenter look at a chisel sharpened to 90 like it was meh...

One thing I discovered during the course of my knife sharpening business, is how some customers reject modern sharpening methods (like my Tormek T8) to validate the methods that they've been using for the longest time as still "the best".

So the carpenter treating your 90 BESS sharpening as meh, may very well have nothing to do with your processes & results, but more to do with him trying to validate what he's always been doing as still "the best". A real life example, is how a local butcher turned down a free sharpening from me because he only believed in his own sharpening methods. His knife had only been thinned, no secondary bevel left, and the mystery whetstone he was using was like a misshaped bar of soap.

Another example was how a restaurant owner who was proud of learning how to sharpen knives since he was 14 (he was in his 50s when we spoke) but couldn't define what "high carbon steel" was, had no concept of knife geometry, as well as knife anatomy. The biggest indicator to me was when I offered to do a sharpness test on any of his knives for free (using my PT50A), and he immediately refused. That told me that he was rejecting me not because my methods and case studies sucked, but he was more worried that I would make his knives actually sharper, and totally invalidate everything he thought he knew.

#94

Knife Sharpening / Re: Beyond Basic BESS

Last post by BPalv - July 26, 2025, 03:56:44 PM

Edge retention is still something that is somewhat of a mystery to me.  I have tried 600 grit and very little honing to highly polished.  Neither seem to be superior in terms of edge retention.  That is, retaining a 70 edge on the BESS.
After use, all steels I have sharpened lose that super sharpness in the first couple uses.  Some steels jump to a 140, some to 240 on everything but the softest foods.
They all seem to lose that eye popping sharpness very quickly.
I only have my tests to gauge this on.  I haven't seen any tests for real world usage to measure how fast the edge degrades.  I suppose CARTA tests do show the degradation but usually they demonstrate how long the usable edge lasts, not how long they stay ultra sharp.
Once again, how sharp you need/want to keep your tools/knife is very personal.  I had a carpenter look at a chisel sharpened to 90 like it was meh...

#95

Knife Sharpening / Re: Beyond Basic BESS

Last post by ABall - July 26, 2025, 08:47:52 AM

If I can confirm burr removal with the Bess I will keep an eye on retention. I keep a huge roll of cling film in my kitchen drawer from costco and its the best thing I have in the house for keeping an eye on my knife edges. I slice it every day to wrap my sarnie and it tells me when the edge has gone. I will do a test next time it doesnt glide through the cling film.

#96

Knife Sharpening / Beyond Basic BESS

Last post by Ken S - July 26, 2025, 01:20:44 AM

Most BESS users strive for very low scores immediately after sharpening. I call that "basic BESS". While that may seem to bring bragging rights, those rights are short lived. In my opinion, using BESS to help determine the staying power of sharp edges is more useful. This extended testing can be to include comparing longevity of edges with different bevel angles, grinds, or steel.

Ken

#97

Knife Sharpening / Re: 2 knives, same angle diffe...

Last post by RickKrung - July 25, 2025, 06:13:39 PM

It's not so much the spine thickness as it is the "thickness behind the edge".

...snip...

And as the same knife is ground with repeated sharpenings, the "thickness behind the edge" begins to increase as the bevel migrates toward the spine.  This would result in much smaller differences, hardly noticeable until it has gone a long way and probably not nearly as much as shown in the OP's photo. 

#98

Knife Sharpening / Re: 2 knives, same angle diffe...

Last post by ABall - July 25, 2025, 08:53:01 AM

It's not so much the spine thickness as it is the "thickness behind the edge".

Of course, knives with a thicker spine will - generally speaking - be thicker close to the edge. And if the knife is twice as wide close to the edge, the bevel will be twice as high.

This is not true with some japanese knives (honesukis for instance), that have a thick spine and a very thin edge.

Ah yes thank you that makes perfect sense.

#99

Knife Sharpening / Re: 2 knives, same angle diffe...

Last post by tgbto - July 25, 2025, 08:07:06 AM

It's not so much the spine thickness as it is the "thickness behind the edge".

Of course, knives with a thicker spine will - generally speaking - be thicker close to the edge. And if the knife is twice as wide close to the edge, the bevel will be twice as high.

This is not true with some japanese knives (honesukis for instance), that have a thick spine and a very thin edge.

#100

Knife Sharpening / Re: Is there still a wire burr...

Last post by tgbto - July 25, 2025, 08:02:34 AM

Vadim was very clear when he stated the sharper a knife is to start, the longer it will remain sharp.  Depending on the use of course.
My target when I sharpen is 100.

I haven't read Vadim's book in a while but I think I remember him saying that initial sharpness was a lesser factor wrt edge retention than the bevel angle.