Years ago, I got a neighbor friend who worked at a large plant to get me their used files for some homebrew wood chisels. They even used a plane surface grinder to remove the grooves - great! I then ground the rough skew angle with a die grinder mounted stone, wrapped it in a cloth, held it in a vise, and whacked it on the grind, shattering it like glass - cool, I thought. I shaped the edge and sharpened it on a 1"x42" belt grinder, down to 320 grit SiC - nice edge - finished it on stones to shaving sharpness - yippee, I thought. I didn't know about the micro-cracks I had produced - and how, even with the minimal shock of chiseling wood (I made a few mortise chisels for myself and my neighbor.), they might connect - and I'd lose a hunk of the edge - which I did - stuck in a mortise - fun to extract. The neighbor came back with one with a big piece missing. We both agreed - we weren't metallurgists. Ford was President... I found some clearance priced Japaneese laminated mortisers at a local shop.
You have to anneal the snot out of file blanks - then shape them and remove those grooves - then reharden the blank before finishing it... but you have a forge, so you know and do this. My hat's off to you - great job - neat design. Traditional wood handle, or dymondwood/micarta? That short tang may be a problem. I am anxious to see the results.
Stainz
