Review of “Sharpening for Conservators” Workshop

Dan Smith wrote this review for the Guild of Book Workers Newsletter, April 2015, No. 219. If you are not a member of the Guild, you are missing out on a lot of other things: workshops all over the US by professional bookbinders, a bi-monthly newsletter, an infrequent journal, a secret handshake, and a yearly conference.

edges

 

Having an Edge: A One Day Workshop with Jeff Peachey

Review by Daniel Smith

I often wondered why such an important component of bookbinding—sharpening, seems so overlooked in workshops and general instruction. Dull knives can be the source of great frustration. Jeff Peachey has spent much of his career fixing this situation. He ran a one day workshop recently at The Conservation Center on the Upper East Side of Manhattan demonstrating his technique. Here’s what I learned.

We were given a choice of right or left hand English paring or Swiss knife blanks to work on. All had been machine ground to the correct bevel of 13 degrees and our assignment was to sharpen and hone the blade.

Thou shall not round the bevel.*

If uneven pressure is applied while sharpening, the bevel can develop an obtuse roundness that requires a regrinding to remove. This is the most common mistake. This problem can be avoided by placing the knife bevel side down on the film and pushing down on the edge and allowing it to lock into the proper angle. This is something you need to get the feel for.

Thou shall sharpen side to side.*

The idea is to use increasingly finer grades of abrasive film (3M Microfinishing film) to achieve the finest edge. The strips of film are mounted on Delrin, a plastic with hardness and rigidity like steel. The film is backed with a pressure sensetive adhesive that allows it to be reused. The first grade was 80 micron. This was used until all the deeper gouges from the machine cut are removed.  This stage is the easiest to see the difference between the old surface and the new. It also takes the longest. Four fingers hold down the blade edge as you pull it side to side across the film using plenty of water as a lubricate. The water darkens with the tiny particles of steel that are removed from the knife called swarth. This is the aluminum plate sharpening system found on Jeff’s web site.

Thou shall not advance to the next grit until the burr develops.*

Once you’re done with the bevel side you need to grind the flat side to remove the burr that has built up. Feeling the burr is a good way to tell how evenly you’re grinding. If there’s less burr on one side more pressure must be applied while grinding. Jeff recommends using grits half the size of the previous one, so from 80 micron we went to 40, then to 15 and to 5. It was increasingly harder to see what you’re accomplishing with the finer grits but by [feeling the burr and] careful inspection we made progress. I found the concept of creating a knife edge so sharp that it would easily pare leather a bit intimidating so I thought of the process more like polishing than sharpening.

Another aspect I found intimidating about sharpening a knife was wondering if I would have the  patience to finish what I suspected might be a long and tedious process. This was not a factor at all. Granted this was a motivated group comprised of conservation students, bookbinders and one guitar maker, [but] Jeff’s enthusiasm and knowledge empowered us and made us eager for all things that could cut.  I know a few of us felt that we were finally being let in on a great secret and that we would soon be able to exert some control over the drawer full of dull knifes in our studios. What kept me going was knowing that the final result would be a knife I could trust.

Thou shall not covet, or borrow, thy neighbor’s knife.*

Mr Peachey shared with us many of his old tools, relics from the industrial age, that’s he’s collected from flea markets over the years. Knifes made from ground down files, an instrument for carving your name in logs, a bee-keepers knife, handmade chisels, knifes for picking bananas or shaping the heel of a shoe or cutting wallpaper or rope. He explained its original function and shape and showed how the years of use by a long forgotten craftsmen has resulted in its current form. He also brought his collection of vintage double edge razor blades as well as ingenious devices used for sharpening them,

We were encouraged to bring our own knifes and sharpening equipment for evaluation and it was a mixture of relief and disappoint to learn that some of the items were useless for the purpose they were intended. Disappointment in that the item was a waste of money and time but relief to know it was the tool and not the hand. Some learned their favored items could be salvaged and were worthy of the effort.

Jeff went through the process with us with a knife of his own, showing us what to look for and demonstrating the proper way to hold the blade. evaluating the progress with comments like “Now I could sell this knife.” We were well into the work when Jeff finished his and demonstrated the cutting ability. The moment we had been waiting for. Gasps went out as his knife pared the leather perfectly, and well, there’s no other word for it, like butter. We returned to our work with renewed determination.

Stropping the blade is the last step of the process. This is the familiar motion barbers use on a single edge razor before shaving a customer. Our strop was horse butt leather coated with .5 micron chromium oxide on the flesh side. This is a different motion than the side to side sharpening action. The knife is held perpendicular and pulled away from the substrate. Properly sharpened knifes can be stropped to produce a very sharp final edge. Double edge razor blades can be stropped to restore its sharpness.

My knife is now a prized possession, cuts leather beautifully and nice to look at. A bit of stropping brings the cutting edge right back into form. Final lesson: It’s a major faux pas to borrow a colleague’s paring knife, so don’t ask.

* from Peachey’s Ten Commandments of Sharpening

The Guild of Book Workers Website

New! Aluminum Plate Sharpening System II

I’ve made three significant improvements to the aluminum plate sharpening system. First, the plates themselves are now a half of an inch thick, rather than a quarter.  This aids in their stability if used without the holder. Secondly, the plates are now machined with a flycutter, which results in a flat surface and regular pattern.  Thirdly, the plate holder has been redesigned. Now, a knurled adjustment knob allows quick and easy flipping and switching of the plates without tools. It now only takes 3 seconds, even if you work slow. The stand is all aluminum with stainless steel screws so there is nothing to rust.

These plates are used the same as any sharpening stones. The plate holder has four rubber feet to keep it from sliding around. I generally use water as a lubricant to keep the metal particles from glazing over.

This is the system I use to make and sharpen all of my knives. People often ask how long each abrasive sheet lasts, and although there are many variables, I’d guess I can generally sharpen about 10 knives on each one. Of course, if you are trying to reshape a bevel angle or repair a major chip you might use up an entire sheet. When a sheet is exhausted, simply peel it off and stick a new one one. You must trim the edges of the edges of the finishing film when you put a new sheet on, so that it does not overhang the edges. Otherwise it may give you one of the nastiest, dirtiest, slow-healing cuts you have ever had, DAMHIKT. 80 micron replacement sheets are available from Rio Grande; the 40, 15 and 5 micron from Tools for Working Wood.

I’m convinced it is the easiest, quickest, and most convenient way to resharpen and keep all your knives and edge tools in peak condition, from scalpels to scimitars. This system is a lightweight, easy to store and unbreakable. Perfect for travel and classroom use.

The system comes with four 11 x 2″ strips each of 80, 40, 15 and 5 micron #3M PSA micro finishing film, a 12 x 2″  Genuine Horsebutt Strop, and 1 oz. bar of green chromium oxide buffing compound. The entire system is 13 x 3 x 2.5″, 3 lbs. 4 oz.

ITEM #SS2: Introductory price  $225.00

Tips on sharpening are located here, and tips on stropping here.

Hand Stropping

Above: The Art of Preserving the Hair, On Philosophical Principals.  By the Author of the Art of Improving the Voice. (London: Septimous Prowett, 1825), 250-251.

Before you try this, think of the way your strop gets to torn up in use!  I have tried hand stropping—very carefully—but didn’t notice much difference in the sharpness of the blade as compared to stropping on an undressed vegetable tanned hair side skin, to be honest. Hand oils may give the steel a bit more resistance to rusting. Needless to say, hand stropping is performed slowly.  I still prefer a Horse butt strop, available here.

Hand stropping lives on in various guises, however. Shaving enthusiasts have a thread titled Hand Stropping Really WORKS!. A youtube video demonstrates the stropping of a single edge razor blade. Bill Carter, a plane maker from the UK hand strops a plane blades. To be clear, he is pulling the blade away from his hand.

Below: The tough hands of Bill Carter.