Just Got A T-4 and a 1x30 Belt Sander, Advice Needed

[kwakster]

Why do you call them mirror edges ?

[John_B]

Why do you call them mirror edges ?

If you truly have a mirror bevel you can hold it next to print and easily see the letters in reverse like a glass mirror. As you are slicing the shiny bevel will have less friction than a rough one making the cutting easier.

[kwakster]

I know what a mirror edge is supposed to look like, it's just that so far i haven't seen one in this thread.

This is a mirror edge on a user Spyderco PM 2 in CPM-M4 steel i did on my Paper Wheels some time ago.
(you can enlarge each picture 2 x for more detail):

[jasonstone20]

I wasn't trying to show off my mirror edges.  I am trying to show the difference between the results I am getting from the Tormek and one on the fixed system I have, so I used camera angles that caught the scratch whole scratch pattern, like you can see was done on your shot were you can see the scratch patter at the heel of the blade. 

[jasonstone20]

Here is the exact same knife with the same edge, just different lighting:





Here is the image with the lighting showing the scratch pattern:



Happy? 

[Ken S]

Years ago, I worked with woodworking writer, Pat Warner, on the photography for three of his books. Metal is difficult to photograph well.

Ken

[kwakster]

I'm not quite sure what that area in my own picture number 2 shows, it's either a trick of the light or i didn't polish the entire bevel there.
Whatever it is, that part of the image isn't representative for the bevels & apex which were sharpened on a Paper Wheel with 15 micron diamond compound, then refined through 6, 3, and 1 micron diamond compound on other Paper Wheels.
No Tormek stone that i know of comes close to that level of refinement, but of course it isn't often required or necessary.
Using lighting to catch different scratch patterns in pictures is something i do as well, but from your posts it wasn't clear to me that you were doing the same.

[jasonstone20]

No problem, it was my fault as I assumed from the previous posts in the thread that it was obvious that is what I was doing.  I often forget that other people aren't thinking the same thing as I am, so I apologize for not explaining what I was doing.

[kwakster]

We're all in the same boat, learning new things everyday, 
Here's an example of how i use daylight coming from the right hand side to compare old and new scratch patterns in edge bevels.

The first owner of this small Sebenza apparently thought it a good idea to use the knife for sharpening practice in his new Wicked Edge.
The outcome made him sell the knife for a measly 150 Euro's to owner number two, who sent it to me with the request to tidy things up a bit and give it a bit of a shiny edge.

Below is what the knife looked like when i received it, still with it's very rough and partly unapexed "edge", and with an edge angle of ~40 degrees inclusive at the straight part of the edge, changing into ~45 degrees inclusive from belly to point.

[kwakster]

After reprofiling & sharpening on a Paper Wheel with 15 micron diamond compound, then deburring and polishing it a bit with a second Paper Wheel coated with 1.0 micron diamond compound.
The new edge is a bit convex, and measures ~30 degrees inclusive on the straight part of the edge, changing into ~35 degrees inclusive from belly to point.
This to avoid widening the bevels there too much, as this blade is relatively thick behind the edge in that area.
The last picture shows a small facet at the heel which has an entirely different angle, so i could not remove it without making things worse.
Visually it's not perfect yet treetopping sharp, and the owner was happy.

[jasonstone20]

Nice work.  What I am trying to do is get a mirror edge with the SG-200 and the honing wheel.  I was told it was possible, and have gotten pretty close myself.

[Ken S]

Jason,

I have had the pleasure of working with Tormek knife expert, Stig Reitan. Stig uses your desired SG-200 and leather honing wheel with PA-70 compound technique. He has also worked extensively with the T4. His sharpening skill is impressive. He will tell you that he uses the stone grader a lot. He also uses more grinding pressure and honing compound than most users.

I believe the real source of Stig's mastery of sharpening is the years of dedicated focused practice in learning the craft.

Your goals, like many of us, go well beyond basic sharpness. There is an expression in Spanish, "No se ganó Zamora en una hora" (Zamora, the last Moorish stronghold in Spain, was not conquered in an hour. An English language equivalent would be "Rome wasn't built in a day".) Be patient. Keep working. You will reach your goal.

Keep posting.

Ken

[jasonstone20]

Ken and kwakster, thank you for the help.  I will keep working on it.

[jasonstone20]

Ok, I am having better luck with both the sharpening and the polish on the edges.  It helps not to have very wide bevels like I was running, and also to have the knife clamp set as close to the center of the blade as possible, to get an even edge bevel.  Fresh honing compound also helps with the polish on the edge.  I am really enjoying using the Tormek T-4, as you get a decent level of sharpness in a small amount of time.

[cbwx34]

Ok, I am having better luck with both the sharpening and the polish on the edges.  It helps not to have very wide bevels like I was running, and also to have the knife clamp set as close to the center of the blade as possible, to get an even edge bevel.  Fresh honing compound also helps with the polish on the edge.  I am really enjoying using the Tormek T-4, as you get a decent level of sharpness in a small amount of time.

Always clamping the knife in the center won't necessarily result in an even bevel (this is probably just working by coincidence).  Clamping should be based on the distance from the belly to tip area, for best result.