Knife troubles! Can anybody help me?

I recently aquired a case xx knife, the model number is 6256 sab. This has it rolling of the production line in the early to late 70's. My issue is the damn thing won't take an edge. I spent an hour on a water stone(my oil stone isn't available) trying to put an edge on it. After awhile I was despereate for just a workable edge, so I used my fathers kitchen knife sharper(f�ri from ozitech. It is diamond, and almost idiot proof), and after checking for an edge many times 20 minutes later still there was't any sharp edge. I'm getting pissed, I learned how to sharpen from a pro, and never had issues like this before.