Re: Heat treating
ThomD
>You want to go to about 1/16" as Bob mentions. What happens is that it will be a lot harder (duh) after you have hardened it, and it will be much harder to grind, and you will need to grind it more slowly since if you overheat it by just a fraction you will draw some of the temper. So it is a ballancing act, between killing it during the HT because you left the edge too thin, and killing it during the grinding, unless you just have a lot of time on your hands. one little trick you can use if you aren't too perfectionist is to grind to a fat 1/16" at 25 deg before you HT. Easy to grind etc no effect on the HT. Then when you have to grind to the final edge, you go for 30 degrees (or whatever combo of angles you prefer), which leaves you with less metal to remove, yet you had the fat edge. You can end up with none of the original shallower bevel showing since while you had to steppen the angle, you also removed the thickness. On the other had if having a tiny bit of the old bevel showing is going to ruin your day, either work it out on paper first, or forget it.
I just made a holdown a few weeks back. I pasted a pic. I had never done it before, and was just foolin around, and it was dead easy. Just wack the end with a hammer until it is a flatened pad. Flip it over and radius it on the horm.
Then heat the shank where you want the main bend, and brace that over the horn and in steps bring the curve to where you want it. That took me several heats. I did it to the final angle mentioned in the thread. But if you bring a drilled piece of wood the size of your bench top you will be able to experiment with the final setting angle so that it works with your top thickness and such. Remenm ber you can fix "mistakes" in hot metal.
There is another method for doing an HD where you get a 90 degree transition to the horizontal part of the HD. This is a lot more complex. I saw instructions for it. You can't just bend it or you get a crimp. Looked totaly doable for a newbie, but I would need to find the steps again. Your buddy probably knows what is required since this must be a comon problem in shaping hard corners. The Roubo HDs in the Landis book are done this way. I just made the shepard's crook variant, which seem to be pretty popular right now. Actually the hard cornered ones are like the cast ones that various woodworking stores sell. But they need a more flexi material than cast iron to work,