03-25-2020, 11:33 AM
I just did some more work on my (now world) famous Tramontina kitchen knife. The one that scored about 190-ish after very careful deburring, following a 380 grit belt. Well I decided to polish it a bit so I used a 600 grit belt, then leather, scotchbrite, leather again. Terrible scores! 200, 350... So more polish. I went straight to a smooth leather belt with green compound. Very little compound left on the belt, but it's there. Eliminated the remaining LOW. ...and it scored 125, 125, 175. The 175 was in the curve. So back to the loaded leather. I did 5 or 6 passes and got a little too casual with my motions. Sliced open the top of my index finger. Ooops. Nice *cleeeeeean* cut though. It didn't even bleed for 20 or 30 seconds.
After cleaning that up, I tested the curve again. One handed, because I was holding pressure against the finger of one hand. Balanced the blade on the fulcrum on the tester, and leaned it over to the media. Lean, lean, lean, lean... and the media broke. At 80 grams. No freaking way. I must have sliced it somehow.
So I went and got a bandaid and got my finger taken care of. ...and tested again. In the curve with the fulcrum, but this time with the other hand on the tip of the blade helping to guide it down. ...and it read 135. Now that's more believable.
I can only guess that with one hand the blade slips some and creates a slicing motion, which obviously "tricks" the tester because the force is not straight into the media, it's at an angle. I think if you were really clever you could slide the blade sideways and get nearly zero readings by doing an extreme version of this. Does that sound about right?
Anyway, seems like I need to be more careful when sharpening knives.
Brian.
After cleaning that up, I tested the curve again. One handed, because I was holding pressure against the finger of one hand. Balanced the blade on the fulcrum on the tester, and leaned it over to the media. Lean, lean, lean, lean... and the media broke. At 80 grams. No freaking way. I must have sliced it somehow.
So I went and got a bandaid and got my finger taken care of. ...and tested again. In the curve with the fulcrum, but this time with the other hand on the tip of the blade helping to guide it down. ...and it read 135. Now that's more believable.
I can only guess that with one hand the blade slips some and creates a slicing motion, which obviously "tricks" the tester because the force is not straight into the media, it's at an angle. I think if you were really clever you could slide the blade sideways and get nearly zero readings by doing an extreme version of this. Does that sound about right?
Anyway, seems like I need to be more careful when sharpening knives.
Brian.