Restaurant commercial knives

[MaxtheKnife]

Ok.....here we go....I have a question.
I have several restaurant accounts and I switch the knife sets out every 3 weeks......average 7 to 12 knives each........mostly white handled dexters, but some are Lasting Cut.....90% are chefs.
Often I have to buy new knives and local vendor sells the Lasting Cuts, so those are what I use.
.
My question is:  when I take these out of plastic cover, they have small bevel......no polish.....groves........BUT THEY ARE RAZOR SHARP.......anyone like to comment on how they get them that sharp.?.?......slice maters in the air.
.
I have never been able to duplicate that edge.
.
The edge looks like 120/220 grit finish......

[grepper]

Can you be more specific about what you mean by "razor sharp"?  Can you put a number on that?

[Rupert Lucius]

Max

The time has come to go ahead and purchase a EdgeOnUp? If for any reason you are not satisfied with your purchase - ship it to me and you will receive a full refund. A win/win!

Rupert is using the PT 50 B - perfect for our needs.

[MaxtheKnife]

Can you be more specific about what you mean by "razor sharp"?  Can you put a number on that?

Nope
For a $14.00 banger knife right out of the box it is sharp......sharper than any new deter I ever bought to rent..
Most new shuns and globals I see at W-S are vert sharp as well, but this lasting cut is far sharper than any new henckel or wusthof out of the box.

It is hard to express it

[grepper]

Can you post a link to the $14 Banger?  I'll buy one to play with and test fresh out of the box so we can put a number on it.  That would be very helpful.

Are you sure it's not just really "toothy"?  Toothy can masquerade as sharp.

[Jan]

Ok.....here we go....I have a question.
I have several restaurant accounts and I switch the knife sets out every 3 weeks......average 7 to 12 knives each........mostly white handled dexters, but some are Lasting Cut.....90% are chefs.
Often I have to buy new knives and local vendor sells the Lasting Cuts, so those are what I use.
.
My question is:  when I take these out of plastic cover, they have small bevel......no polish.....groves........BUT THEY ARE RAZOR SHARP.......anyone like to comment on how they get them that sharp.?.?......slice maters in the air.
.
I have never been able to duplicate that edge.
.
The edge looks like 120/220 grit finish......

Max, first think I do with a new knife is measuring the edge angle. Sometimes I am able to measure also the secondary bevel angle. Having both angles is good for future edge duplication.

Because quality Catra instruments were too expensive for me I have made my own instrument which, for my purposes, works even better. The costs were circa $10 excluding children construction set used. My laser goniometer is on the attached pictures.

       

The red laser lines show that the included edge angle of a Mora knife with Scandi grid is circa 23° (2 x 11.5° side angle).

During guided sharpening (e.g. on Tormek) we are thickening the edge, so strictly speaking we can never exactly duplicate an existing edge. But in normal situations this occurs only after many sharpening or after massive steel removal.

I am attaching Victorinox recommendation dealing with this issue.

  servive-cut-grinding-sharpening-en-nov2012.pdf (Size: 168.24 KB / Downloads: 17)

Jan

P.S.:  The laser line is splited and reflected on the knife edge. The reflected rays draw two lines on the cross board which is calibrated in degrees.

   

[Edgepal]

Jan,
My English is at it is and I can easy missunderstand things I read....

But you wrote that "we can never duplikate existing edges". My sharpening tool EdgePal Chef can duplicate edges exactly. With exactly I ment down to 1/100 part of 1 degree.

To do this is a matter of how fine you can adjust a sharpening tool. The pivot point on my tool Chef are mounted kn a bar. The height of this bar is asjusted by two special nuts that clamp the bar between them. The nuts can be adjusted be oss they can be screwed (?) along a M4 standing screw. 1 full turn of the nuts change the edge angle with 7/100 parts of 1 degree. That means that 1/7 of a full turn change the edge angle with 1/100 part of 1 degree.

The nuts I talk about above have markings on them, a small black dot. Withbthe help of this dot you can se how much the nut is turned - and in this way you can asjust the edge angle very fine.



This picture shows two knifes. The upper knife have three differetn bevels, 9, 10, and 11 degrees. The 10 degree bevel is not polished, I have left it raw.

The other knife have 5 different bevels. They are about 1 mm wide, there is 0.75 degrees between them and they are straight from the handle and belly out to the tip.

With my tool Chef can I go from bevel to bevel and hit the bevel 100 % correct by using the black dot on the clamping nuts I talk about above.
* Notice, this is a standard function on my sharpening tool Chef.

Chef also sharpen both flat and convex edges in wanted degrees - and convex edges can be made in wanted convex sphere in degrees. This means that if you like ro have a convex edge with 3 degrees convex sphere and 26 degree total cutting edge - you adjust for this on Chef - and you will get it on the edge.
That is also a standard function on my tool Chef.

If you like to meaasure how many degrees an edge holds you can meassure this with Chef. Just lay the knife on the grinding tables magnets, adjust the distance 28 cm between the edge and the pivot point (with the help of markings on the guide rod). Use a whiteboard pen and draw a line across the edge. Lay down the sharpener on this line, adjust the bar untill the sharpener take away the whitboard pen line - and read on the built in protractor the degrees on this edge. Very simple to do.

A thing that can be nice to know when adjusting like this. A whiteboard pen leaves 2/100 part of 1 mm thick ink on the edge.
A permanent ink line is 1/100 prart of 1 mm thick.
When I make multipel bevels on a edge I use permanent ink

Thomas

[MaxtheKnife]

Can you post a link to the $14 Banger?  I'll buy one to play with and test fresh out of the box so we can put a number on it.  That would be very helpful.

Are you sure it's not just really "toothy"?  Toothy can masquerade as sharp.

here are 3 pics....they offer many styles...........and made in china
.
.

[grepper]

I searched around and can't find them, other than people saying that they find them in local restaurant supply stores.  There is only one such store around here so I'd have to get really lucky.  Ever pull a new Victorinox chef's knife out of the package and feel it?  How does that compare.

If you get a sharpness tester we could figure out how sharp it is and have some way to communicate it's sharpness level.   I put off buying one for a long time.  After I got the PT50B, the first time I used it I understood what I had been missing.

[Jan]

Jan,
My English is at it is and I can easy missunderstand things I read....

But you wrote that "we can never duplikate existing edges". My sharpening tool EdgePal Chef can duplicate edges exactly. With exactly I ment down to 1/100 part of 1 degree.

To do this is a matter of how fine you can adjust a sharpening tool. The pivot point on my tool Chef are mounted kn a bar. The height of this bar is asjusted by two special nuts that clamp the bar between them. The nuts can be adjusted be oss they can be screwed (?) along a M4 standing screw. 1 full turn of the nuts change the edge angle with 7/100 parts of 1 degree. That means that 1/7 of a full turn change the edge angle with 1/100 part of 1 degree.

The nuts I talk about above have markings on them, a small black dot. Withbthe help of this dot you can se how much the nut is turned - and in this way you can asjust the edge angle very fine.



This picture shows two knifes. The upper knife have three differetn bevels, 9, 10, and 11 degrees. The 10 degree bevel is not polished, I have left it raw.

The other knife have 5 different bevels. They are about 1 mm wide, there is 0.75 degrees between them and they are straight from the handle and belly out to the tip.

With my tool Chef can I go from bevel to bevel and hit the bevel 100 % correct by using the black dot on the clamping nuts I talk about above.
* Notice, this is a standard function on my sharpening tool Chef.

Chef also sharpen both flat and convex edges in wanted degrees - and convex edges can be made in wanted convex sphere in degrees. This means that if you like ro have a convex edge with 3 degrees convex sphere and 26 degree total cutting edge - you adjust for this on Chef - and you will get it on the edge.
That is also a standard function on my tool Chef.

If you like to meaasure how many degrees an edge holds you can meassure this with Chef. Just lay the knife on the grinding tables magnets, adjust the distance 28 cm between the edge and the pivot point (with the help of markings on the guide rod). Use a whiteboard pen and draw a line across the edge. Lay down the sharpener on this line, adjust the bar untill the sharpener take away the whitboard pen line - and read on the built in protractor the  degrees on this edge. Very simple to do.

A thing that can be nice to know when adjusting like this. A whiteboard pen leaves  2/100 part of 1 mm thick ink on the edge.
A permanent ink line is 1/100 prart of 1 mm thick.
When I make multipel bevels on a edge I use permanent ink

Thomas

Thomas, your English is fine, my is secondary language also.

My statement "strictly speaking we can never exactly duplicate an existing edge" was not about edge angles, but about the fact that each sharpening removes some blade material and makes the edge thickness larger, because it widens towards the spine. After many sharpening this increase may be so large that the knife does not perform well. Victorinox recommends to keep the edge thickness between 0.4 to 0.6 mm. Panta rhei (Heraclitus), "everything flows".

I know quite well your sharpening tool EdgePal Chef because it is on my wish list, but thanks for your additional explanations. I know that the angle setting accuracy is far beyond the needs of a standard knife sharpener. You claim that the accuracy can be 1/100 part of 1 degree. I am wondering if you can guarantee this accuracy along the whole edge – from the heel to the tip.

The upper Mora knife on your picture probably does not have a consistent bevel angle along the whole edge. Changes in the height of the edge on your knives indicate possible significant change in the bevel angle. The lower knife seems to be OK.

   

Your mechanical protractor is surely good for measuring bevel angles, but cannot measure a microbevel with a height of 0.1 mm (100 microns). Even for my laser angle master it is a very challenging task. Unfortunately such a microbevels are typical e.g. for new Morakniv knives.

   

Jan