Shaping the Blade. Shaping the blade will require some equipment. If you are really on a shoestring or just don't want to go through this, buy blades and mount them in a handle. But, if you really want to have some fun, take a shot at making a blade from scratch. The following discussion is applicable to almost any material you run across. You must go slow so that you do not make the metal overheat. (Turn blue, or worse yet, black) You can forget about using any blade that has turned blue. Grind it down to fresh metal or get a new piece. Overheating causes the metal to lose its hardness (temper) and it will not hold an edge. This applies to any tool you sharpen, not just the ones you make yourself.
|Select a shape and size. Here is the first
knife I ever made from a razor blade. The blade is 1.25"
long. The handle is red heart and I used a little piece of white
plastic as an end cap to hide sloppy workmanship. This is an
exercise in making the blade, not precise craftsmanship. Precision will
come later, with practice, but the plastic cap is still a nice touch.
Mark the shape that you want on the blade. I use a felt tip marker because a scribe generally won't scribe the hardened razor blade. The shank of the razor will be mortised into the two halves of the handle and glued using epoxy.
|By the way, this shape and size is a real wood hog. I still use it today and it takes off the wood smoothly and accurately. Make sure that you get a razor that has some heft to the blade all the way to the edge. Some are so thin at the sharp end of the blade, they won't stand up to heavy carving. The thin part has to be removed and you wind up with a thin detail knife.|
|Shaping the Blade. The best way I have found to
shape the blade is with a Dremel cut-off wheel. This is the little
abrasive wheel that will cut almost anything.
Keep it cool. Place a sloppy wet rag on the work table and lay the blade on it. Holding the blade with a vice grip may help until you get the hang of it, but I just use my fingers..
Turn the Dremel to high speed and make light easy passes along the mark until the blade is cut all the way through. Go slow and work the thick area first. Be especially careful about overheating the tip. Make sure that the tip is very wet or you will turn it blue before you know it.
"Adjust" the thickness. Once the blade is shaped, you will need to grind it to the shape you want. Some materials are too thick to cut through the wood easily. The spine of the razor blade needs to be thinned. Some razor blades are very thick and require even more thinning than others. Scissors usually require thinning, also. Adjusting the cross section of the blade to your favorite cutting shape must be done with power equipment. You can do some things with a file or stone, but making blades from scratch requires power, especially when you are using these hardened materials.
The Dremel, with all its attachments is a good start. There are abrasive wheels, stones, and sandpaper cylinders in various grits. An 8" two wheel grinder will also make the work easier. With a high speed grinder, you must go even slower and use water to keep the blade cool. I use a wet rag to hold it and keep water handy to cool between each short pass on the grinder. Grip the blade between your fingers and if it is too hot to hold, it's too hot.
Sharpening equipment is also a definite advantage. See the section on Sharpening. I use belt sanders, sanding cylinders and disks mounted on old motors, and a slow speed sharpener made with an old dryer motor. As you see, I like old machine motors. You can pick them up at flea markets and garage sales, cheap. I am also not above asking a neighbor if I can scavenge the motor out of the washing machine or dryer he has put out on the curb for the trash. A keen eye is worth real money when it comes to getting treasures out of trash. I just have to be careful that my wife isn't looking.