Keep it Clean: Preserving the Life of 3M Finishing Film

One of the most common mistakes in sharpening is to allow your stone or film to glaze over. This significantly increases sharpening time, since the knife is not abraded by the grit, but is burnished against embedded steel. Not using enough lubricant is a common reason for this, as is not regularly cleaning your substrate. Depending on the size of the grit, either a microfiber rag or a white vinyl eraser works best.

My sharpening setup, above, consists of a bright swing arm lamp mounted directly above a cork faced workbench (PSA cork shelf liner), a microfiber rag, a large squeeze bottle of water, and the Peachey Sharpening System. I find it more comfortable to sharpen at a lower height, around 34 inches, than my regular bookbinding workbench. Many hundreds of knives have been sharpened here!

The microfiber rag is perfect for cleaning larger grit 3M micro-finishing film, from 80 to around 15 microns. This rag was white when I purchased it, a testament to how well it picks up and retains small metal particles. I also use it to clean off the knife between grits in order to examine the scratch patterns.

For 5 micron and smaller grits, a white vinyl eraser works wonders.  Pictured above is the neon lime green  1 micron film, which glazes quite easily. Using the eraser on coarser grits eats it up too quickly.

Of course, over time, the abrasive will wear to the point nothing much happens, and you will need to replace it. I can usually sharpen ten knives or so on one piece of 2 x 11 inch film.

By using plenty of water as a lubricant, and cleaning the film after each use, the effective working life of finishing film will be prolonged.

August Eickhoff French Style Paring Knives

A pair of August Eickhoff french style paring knives, made in New York, 19th century.

A side benefit of my regrinding and knife sharpening service is that I get to see some interesting antique knives. These August Eickhoff knives are beautifully made, have a wonderful balance, a lovely patina, and given the amount of distal taper (both on the blade and the tang) must have been forged. Eickhoff also made round knives (aka. head knives) for leatherworkers which occasionally show up for sale today. In the late 19th century, Eickhoff was located at 381 Broome St, NYC, making scissors, woodworking tools, and resharpening knives. He served on the NY Board of Education, and advertised his wares in a Teachers College Educational Monograph. It may be time to make a few reproduction Eickhoff knives.

Long Live the Superstrop

I introduced the Superstrop about eight months ago, and have been using this one for over a year without having to recharge the substrate, which is a .1 micron Poly Crystalline Diamond spray.  And last month, seven students used it to make a total of 24 leather bindings. So I’m guessing one application of the diamond compound, which comes with a new strop, will last at least a number of years under normal use. The substrate itself is more durable than leather. It holds the small diamond particles in place, allows them to move around a little to expose sharp edges, and doesn’t glaze over.The small knife at the top right is a prototype paper conservation scraping knife. Get the Superstrop here