Knife Shapening

[rmisale]

I am new to the Tormek T7 and can't seem to get a razor sharp edge on my knife.
It seems I can get a better edge by hand sharpening.

This machine has good reviews so it must be something I am doing wrong.

Also when I applied the honing coupond the leather belt became dusty and when I try to hone it seems to make the knife duller.

Could use some help.

Thanks

[grepper]

Welcome to the forum rmisale!

Don't worry, be happy.  Your T7 will get your knives very sharp.

First, watch this:
https://www.youtube.com/watch?v=fYURcwkKGPs

Then watch a few of these:
http://tinyurl.com/qj72hbn

Did you apply a bit of light machine oil to the leather before applying compound?  Don't use too much.  Don't saturate the leather.  You don't want the leather to become slippery and soaked with oil.  A little oil helps with dust.

Search this forum for: oil honing wheel
There is a lot of discussion about it.

You might be using too much compound on the honing wheel.  In this case less is best.

The idea is to have the leather wheel hold the compound in the surface of the leather to make an abrasive surface.
http://forum.tormek.com/index.php?topic=2388.msg11870#msg11870

http://forum.tormek.com/index.php?topic=2388.0

If this stuff does not help, just let us know.  Folks here respond quickly, are an amazing resource and more than happy to help!  You will have sharp knives. 

[Ken S]

Very good reply, Grepper. Welcome to the forum, rmisale. Don't be shy about asking questions. We have all been beginners at one point.

Ken

[Jimmy R Jørgensen]

Also, i expect that everyone need a little time getting used to it and gettig good at it.. i know i do (still )

[rmisale]

Thank you for the replies.
I did add the oil and then the compound as per the start up guide.  the leather wheel looks white and dusty. 
i have spend a bit of time sharpening a couple kitchen knifes at 20 degree angle with dressing the stone using the fine grit but it just doesn't seem to get there.

I guess the question is can a skilled person using the T7 get a razor sharp edge?  or do you need to get the Japanese stone (4000 grit) to get there?
I would hate to have to go spend another $400 to get the sharpness i am looking for.

Thanks again for all your help

[grepper]

Let's see if we can figure out what's happening. 

As far as sharp goes, I can think of a couple of things that have caused me difficulty.

Not grinding to the edge:  If the angle is set too low it is possible to not grind all the way down to the cutting edge, basically is creating a new less acute bevel angle.  The amount the edge is missed can be very small and difficult to see, but if the actual edge is not ground the knife will obviously not get sharp.  Just as a test, try increasing the sharpening angle to eliminate the possibility of missing the edge.  Another way to deal with this situation is to spend more time grinding with the wheel dressed to a coarse grit until you are sure a new bevel angle has been completely formed.

It can be helpful to paint the bevel with a marker pen and then slide the knife back and forth sideways on the wheel or slowly spin the wheel by hand.  Then check to verify that the ink on the bevel is wiped away down to the cutting edge.

Not spending enough time with the wheel ground to a coarse grit:  Knives with very hard steel, HRC 60 and harder, can be difficult to sharpen especially with the wheel ground to 1000 grit.  You can grind away and nothing seems to happen.  Dress the wheel coarse and spend more time until you get a burr, then switch to a smooth dressed wheel.   This can be really frustrating until you figure out what's going on because nothing appears to be wrong but the knife just won't get sharp.

Not forming a burr:  You need to sharpen enough too actually from a burr.  It should be visible under good light, or felt with the fingers, or snag a cotton ball, gauze or other soft material.  If a burr is not there, try spending more time with a coarse wheel. 

Not completely removing the burr:  A sharp knife will seem dull if there is still burr material on the edge.  Once the burr is removed, it almost magically becomes sharp.  Carefully examine the edge, possibly with a magnifying lens or if you have one a microscope.  If there is still a burr, try some light passes with a smooth wheel and then spend more time honing.

A new leather honing wheel can take a little while to become saturated with enough oil to enable the honing compound to adhere well to the surface.  If this is the case, it will be dusty for a while.  As I remember, soon the wheel will turn black in color and will start to hold compound better.  You might try applying oil to a cloth and lightly coating the surface of the leather by spinning the wheel.  Go easy on this.  It is better to have the wheel to dry than over saturated with oil.  The honing compound contains oil, and with some use the leather will become more saturated and accepting of compound.

Too much oil will cause the wheel to become smooth, rubbery and slippery.  When this happens the compound will just smear around on the surface rather than being held in place to form an abrasive surface.  The same thing can happen with too much compound.  In this case the blade just rides on a goopy coating of compound and it does not cut.  It also makes a disgusting mess.  I wish Tormek would more completely explain the process of breaking in the honing wheel, but with a little time spent I'm sure you will get it figured out.  Once it's right, you can feel the friction, a slight tug on the blade, and actually feel it cutting.

A wheel dressed to 1000 grit will not get an absolutely perfect mirror bevel.  Under a microscope there are still small groves from cutting.  That being said, you need very good eyes, and/or magnification to see it and for all intents and purposes the Tormek knife is extremely sharp with a mirror bevel.

BTW, are you having problems with just one knife?
Have you tried other knives?

I'm sure we can get to the bottom of what is happing for you so any detail you can provide on what you mean by "razor sharp" and what your are not getting would be helpful.

[Elden]

   Welcome to the forum, Raloh.
   I am not sure when you say "a razor sharp edge" exactly what you are trying to obtain. I do not think that you are going to obtain an edge that will do the same thing as a double edge razor blade.  A knife blade is substantially thicker than a double edge razor blade. The edge retention of a razor blade, if it could be mounted in a handle so it could be used as a knife is used, would be terrible.
   However, if you are referring to an extremely sharp knife edge, the anwer is yes it can be obtained without the Japanese stone.

[rmisale]

Wow
You guys are great!!
Thank you for all the help.

Just to answer.
I am trying a few different knifes and i am just meaning a very sharp knife (not a razor blade)

i will try i few of the points mentioned here.

Thanks again

[rmisale]

Sorry, one last question.

In all the video's i have watched the water seems contained to the water trough.  My water spill onto the machine when i am sharpening towards the honing wheel.  I seem to have a lot of water on the blade vs the water in the video's.  I have the water filled to the maximum line.  Is that too much?

Thanks again

[grepper]

I have found that you only need enough water to cover the bottom ½" or so of the wheel.   This will drastically cut down on the mess.  There needs to be enough water to keep the wheel wet and there should be a layer of water riding on the blade as you sharpen. 

Like you, I have found if you fill to the full line it gets pretty messy.  Water on the machine won't hurt anything, but it does make a mess.

Experiment with the water level and you'll get it right.

[grepper]

rmisale- You might find this interesting.

http://forum.tormek.com/index.php?topic=2376.msg11938#msg11938

[rmisale]

Hi
Another question.

It seems that the bevel on one side of the knife is different than the other side.
I do the first side then flip the knife and do the other side.
One is wider than the other?
Just wondering if this could be part of the problem?

[rmisale]

D

[grepper]

What kind of knife is it? How big is it?  What does it measure from spine to edge?  Can you give us a link or a picture?

Was the bevel uneven before you started sharpening it?

[rmisale]

It is a filet knife about 6" blade  and I don't think the bevel was uneven.
I believe it was the same for another knife I was sharpening.

I was using the long knife jig.