A lifting knife is a small knife used for a variety of tasks in book restoration, such as lifting leather from the spine of a book being rebacked, or cutting the paper lining away from the spine. The lifting knife is ideal anyplace a thin, flexible blade might come in handy.
Lifting knives are available where you can purchase other bookbinding tools, and come in a variety of sizes and shapes. Most have wooden handles, and some are designed to be used as paring knives as well. You can also make one yourself if you have access to the proper tools, using these instructions adapted from A Degree of Mastery:
The first thing you need to do is snap a hacksaw blade in half. Mark a line across the middle of the blade at a 45 degree angle. Then place it in a vise or a standing book press with the mark lined up with the edge of the jaws or press. With a heavy pair of pilers, grip the blade close to where it is clamped and snap the top half off with a sharp downward motion.
Next the teeth must be filed off of the two blade halves. Holding each end of one of them with a pair of pliers, apply the toothed edge to a bench grinder or electric grinding stone. Periodically immerse the blade in water to cool it, as the grinder's friction can heat it up too much. Use both hands to make sure you have control over the blade at all times, and above all always wear eye protection.
Once the teeth are ground off, use the grinder to take back the edge of the knife at the angled tip. A cross section of the blade will start out flat, something like [; you want to apply a gentle slope to the end with the 45 degree angle so it looks more like <. Put the grinder away when you've done this to both pieces of the blade; all the rest of the work will be done by hand.
Use sharpening stones in various, ever finer grits to sharpen the edge of each blade along the 45 degree end. Dr. Wilcox used three different grits of Japanese sharpening stones which she kept rinsing with water to keep the surfaces clean and able to cut faster. Then smooth and polish the first two inches of the front and back sides of the blade. This will ensure a clean surface that will offer no resistance while moving across the surface to be cut when the knives are finished.
Now that you have two lifting knife blades ready, you'll need to attach some form of handle to them; working with a bare metal blade is difficult and your hands can slip too easily for precision work. Because lifting knives are most often used nearly parallel to the surface you're working on, something more flexible, and with a lower profile, than a wooden handle is called for. Leather wrapped over cardstock offers just this low profile. Trace around the handle end of the blades onto four-ply cardstock (about as thick as four sheets of paper glued together), and cut out four pieces, two for each knife. The edges of the handle should extend approximately 1/32 of an inch beyond the metal, and should cover all but 1 1/2 inches of the business end of the blade. Fix the cardstock to the metal with PVA glue, and clamp the knife tightly in a press until it's dry.
You'll notice a tiny gap along the edges of the handle where they extend beyond the metal of the blade. This can be filled by finding thread of approximately the same thickness as the metal, and gluing it into the gap. You can repeat the steps above to make blade covers for the knives as well, except you will want to glue the thread into the gap without gluing the cardstock to the blade. Once dry, these covers will slide on and off the blades easily, and will protect the knife while it is being stored.
The final step is to wrap both the handles and the blade covers with pieces of very thin leather, cut to fit around them. Dampen the leather with water (the moisture will keep the leather supple while you work and prevent the glue from drying too quickly), then apply wheat paste to the inside and glue them to the cardstock. Make sure to place the blade covers on the knives to let them dry so they will maintain the shape of the blade properly.
Once all the paste has dried thoroughly, your new lifting knives are ready to use.
The basic lifting knife:
____________+-------------------------+
\ blade | leather-wrapped |
\__________| or wooden handle |
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Special thanks to evilrooster for her review and input.
Sources:
Wilcox. Annie Tremmel. A Degree of Mastery: A Journey through Book Arts Apprenticeship. Minnesota Voices Project Number 88. New Rivers Press. 1999.