I've had my leafjumper in k390 for almost 8 months today and I keep experiencing fairly fast edge wear.
How I'm pretty certain that the edge is good:
→ I've only sharpened it freehand on either 325/400 to 600/1200 grit on both plated and resin bonded diamond stones at 17.4 dps. I would do my best at removing the burr by feeling for it and checking the edge with a microscope and light. I would then strop with alternating passes on a 1µm diamond strop on firm leather for about 4-5 times on both sides. This would almost always result in a hair whittling edge.
→ I also ground down a bit of metal over time, surely removing any burnt/fatigued metal. (the heel is currently 0.020" thick)
→ I was using sharpie on my thumb and pointer finger to keep the angle consistent
How bad the performance was:
→ When I first got the knife, I put my own 600 grit edge on it and cut up about 150' of cardboard. The edge afterwards was so worn, it wouldn't even initiate a slice into printer paper, even after cleaning the edge with alcohol and dragging it on wood to remove any debris blocking the edge. It was as if I dragged it across a brick a few times.
→ Another instance is when I cut no more than 60' of cardboard in 1 week. The cutting consisted of mostly thin cardboard food boxes and thin sheet plastic/mailing boxes. By the end of the week, it could not cut printer paper without significantly tearing or creating a super "fluffy" cut.
→ Even if the edge was never used, the aggression would fade over time
* Something that I think should be noted is that I live a few minutes away from the Gulf in Florida. Also, the humidity here can be anywhere between 55-95% in the warmer months.
How I'm pretty sure my expectations aren't too unreasonable:
This is kind of unrelated to the original post, but I recently got a lw manix 2 in 15v a few days ago. I've decided to use the factory edge (which still has a little bit of burr left) and tried cutting up a lot more stuff and being slightly careless such as making contact with glass jars. The edge is still toothy and sharp and cuts printer paper cleanly.
Edit: the geometry of my 15v manix is 0.025" bte at approximately 20°dps
Thanks for reading my ramblings. Does anyone else have a similar experience with k390? Or am I doing something wrong
EDIT:
Update:
I meant to update yall a few days ago, but I was a little busy. I sharpened it up and it got extremely sharp, a lot of bite, and cut through fragile paper cleanly. So, I carried my k390 outside where I got drenched in sweat. Afterwards, it still cut great with no hang-ups on paper. I went to sleep, next morning, still just as sharp.
That day, I opened up some packages, specifically the tape and applied moderate light pressure to the edge on a cardboard/plastic food container. That is all I cut, and whilst being indoors the whole day btw. That night, the edge was pretty dull as there was no bite left and it could barely cut printer paper.
I decided to sharpen it up a few days later and discovered that with my cheap microscope, the apex was completely blunted. When I started sharpening, I expected a burr to quickly form because maybe I just had a really bad foil burr that was mushed, but aligned and was obscuring the apex. Unfortunately, it sharpened as slow as an edge that was dragged along a brick.
What is going on
