petersenj20 Posted November 19, 2008 Share Posted November 19, 2008 I got the blueprint for the drawknife (Many Thanks Glenn) and I gave it a try tonight using a Nicholson file. It hurt to ruin a good file but I picked up a few for a dollar each at the flea market this weekend. I have no forge so I am using my Al furnace. It is not efficient but does the job. I drew out and shaped the handles OK. Putting the bevel on the blade...Not so good. It took a while and the complete edge is curved like a banana. I understand this is normal with drawing the edge, but I have a few questions.How do you hammer the curve back straight without flattening the edge?When do I sharpen? Before or after I harden and temper?I had a hard time hitting the edge of the file at an angle. Would this be easier with a much thicker piece of metal or do I just need to get it right? After I flattened the whole piece out I left it in the furnace when I shut the fan off to slowly cool. That way I can sharpen in the annealed state unless ya'll tell me to do different. My thinking is to sharpen final edge, heat and harden, then temper in the oven. Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted November 19, 2008 Share Posted November 19, 2008 You have to precurve the blade in the opposite direction before hammering the edge. Final sharpening happens after all heating and tempering. You can grind it close and leave about 1/16" edge, then finish after all the other work is done. Otherwise, you run the risk of cracking, warpage and decarburization. Get the edge of the file close to the edge of the anvil and turn the hammer so the bevel is formed naturally. I have several drawknives that were made from spring steel and all perform well for the purpose. Quote Link to comment Share on other sites More sharing options...
Rob Browne Posted November 19, 2008 Share Posted November 19, 2008 I would try it using clay or scrap mild steel for a couple of runs to get the feel of the drawing and curving then use the tool steel. Quote Link to comment Share on other sites More sharing options...
jimbob Posted November 19, 2008 Share Posted November 19, 2008 How do you hammer the curve back straight without flattening the edge? use a wooden mallet Quote Link to comment Share on other sites More sharing options...
petersenj20 Posted November 19, 2008 Author Share Posted November 19, 2008 All my questions answered. I should have learned how to straighten this but couldn't come up with anything. All my time reading on the site just hasn't sunk in I guess. I think I'm going to leave the curve in place on this knife. I will try the tips on the next one. It was a fairly small file and made a blade about 4 inches long. Much smaller than I would have guessed. My estimate at the handles didn't turn out the same length. I'm going to turn some oak handles in the next day or two and post some pics. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted November 19, 2008 Share Posted November 19, 2008 You don't have to precurve; you can flatten it back to straight *hot* with a mallet or tapping it with a hammer---you want it to bend not deform where you hit it and as you leave an appreciable width to the edge for heat treat reasons you generally don't have a problem straightening this way. Quote Link to comment Share on other sites More sharing options...
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