If the edge does not pass it must either be tempered at a slightly higher temperature or rehardened and the whole thermal process repeated with the tempering cycle set to a lower temperature. I also do periodic destruction testing for two reasons: to see how much abuse a knife can take and to look at the grain of the steel. Again, so as not to be repetitive, please see Terry's post for additional photographs and testing descriptions. For this test I cut some newsprint, chopped some wood and then shaved the hair. The final picture shows a close-up of the blade edge after testing. There are no chips, deflections, flat spots, etc.
The blade passed and is ready for a hand finish. The first thing I do is gently stone or grind off the edge of the blade with a very fine belt, just enough to dull it. I never do finish or assembly with a sharp knife. Next, I hollow grind the handle. This lightens the knife considerably and leaves a nice cavity for the adhesive when I bond the handles. It also makes it much easier to do the final flat sanding due to the smaller surface area. I use the small-wheel attachment with a 1.25” wheel and a slightly worn 50-grit belt.
I will use the Bader and a new 400-grit belt and the leather-covered platen to do the final cleaning of the bevels, then switch to hand sanding. With all of the preparation done before heat treatment and the belt cleanup, I usually only have to use one or two grits to finish a knife. I finish my knives to 400-grit, with a few additional passes using 600-grit paper to make the lines look clean and smooth. When done with the Bader I put the knife in the knife vice for hand finishing. The knife vice is by Rick Leeson, owner of Custer Forge and Welding. He also built my forge.
Custer Forge.
All of my finishes are longitudinal, from ricasso to tip. For the final finish I use oil or Windex. Don't laugh, Windex really works as a cutting fluid! Engnath (
Engnath) has a great description on his site. Select the "Handsanding" choice for a detailed lesson on hand finishing. There are some great diagrams that show the process. I pay particular attention to the plunge area and the area of the ricasso that will be visible between the handle and the plunge, once the handle is in place. The blade is almost ready. Notice that there are still a few scratches in the blade. I will sand these out, make sure the handle is flat, and when all of the scratches are out and the blade looks right, I wipe it with WD-40, dry it off and wrap it with masking tape from ricasso to tip to protect the finish during handle assembly. Unfortunately, I have found that in my damp NW environment I would occasionally get rust on the blade between finishing and handle installation if I get delayed for any reason. The WD-40 seems to work well for preventing the rust.