I traded someone for a CS Recon Tanto on the forums. It had a good edge when I got it. Now, after much use, I find it hard to get an edge back on. I usually don't have any problems sharpening any of my knives, but this one has literally been a bitch. I started by using my stone from my GI pilot's survival knife, which is pretty coarse. Then worked my way down to a fine diamond stone, but still cannot get a hair popping edge. Any suggestions?