The Bleeding Edge

[Colt W Knight]

On my leather working tool strops I use automotive rubbing compounds because that's what I have on hand from building guitars and finishing with lacquer.

Sharpening isn't a big deal once you get your consistency down on your technique. One wrong swipe can erase 50 good strokes.

[TinkerTailor]

The general tool sharpening theory is that the grind marks (be they ever so miniscule) should run in the direction of cutting.

Art

This is really noticeable with scissors. I took a pair of nice shears and at the proper angle, honed them so sharp that i could cut paper with one blade almost silently. I honed them parallel to the cutting edge, put them back together and they just pushed stuff out the tips. They had no bite. One sheet of paper they would cut but fabric no dice. I took them back apart and hit the edge with 600 very lightly perpendicular to the edge, passed them over a strop, and now they bite. I can cut silk to the tip, or 8 oz veg. They eat webbing for breakfast. Before i put the micro-serations in the blades, they would just push webbing out the end, regardless of how sharp they were. I think that sound of a well sharpened pair of shears is the serrations, not the keen edges.

Which brings the question, Is sharpness a measure of the microscopic width of an edge or is it a measure of whether it will cut in its intended purpose?

Arguably I made the scissors duller, but they cut better..

[Art]

Hi TT,

It is amazing what the guy who has been sharpening scissors (stylist) for years can do to a good pair of Japanese hair shears. The German scissors are starting to copy some of the attributes of the Japanese ones. Many hair shears are cut on a radius and have convex edge profiles. If you don't realize this and have a machine and the knowledge to address it, well, the tips won't meet, they will fold and/or push hair, not close properly and who knows what else. It takes over an hour to get a pair like that fixed, and it hurts to tell them their $300 baby may not be repairable.

Art

[Sonydaze]

Between leatherworking, woodworking, metalworking, household and outdoor stuff I do a fair amount of sharpening. Some days I was fantastic at sharpening...other days not so much. I finally broke down and bought a Tormek sharpener and a most of their jigs. The Tormek has a bit of a learning curve but now it is easy to quickly and consistently get the same angle and and a good edge. The stone on it can be changed from 220 grit to 1000 grit with the supplied dressing stone, then you finish up on the leather wheels with their honing compound.

By adapting the planer blade jig, I was able to hollow grind the blades on my Osborne and Heritage splitters. I bought the Osborne splitter for $80 with a really poorly ground blade in it figuring that I would buy it a new blade. I was able to save the blade with the Tormek.

Sharpening scissors, Tormek recommends not honing the the edge.

An interesting video: http://www.youtube.com/watch?v=BQI3TsjKnbU

[Art]

I use the Tormek for Knives, and lathe tools. I need it for lathe tools, because by the time I get the tool and figure out what it used to be, the Tormek is the only way to put a new bevel on the tool. The tormek book, mine is old, it is actually hardbacked, gives me a good of what the tool used to was. But then again, I have made a completely different tools than what they brought in.

For really high grade knifework, you need a belt grinder or stones, there is just no other way to get the finer grits you need.

Art

[Sonydaze]

Art, I agree with you about belts and stones for finer knife edges. I just don't have the time or patience to go there any more.

The Tormek gets me a very workable edge quickly, consistently and it is easy to go back to it for a touch up. It does great scissors and is unbeatable for my lathe tools. For the lathe tools, I have already tried two different systems before the Tormek. My T7 is about a year old, so my books are plastic covered and coil bound. lol

Gord

[Art]

I started sharpening commercial kitchen knives in the late '80s and early '90s. I really enjoyed sharpening and have always enjoyed endeavours that were me and the tool. I fooled around with every abrasive on earth perfecting sharpening, but basically freehand sharpening was not going to cut it. I don't remember how I got in touch with Ben at Edge Pro. I bought one of his setups and eventually a lot of stones films etc. Still have them in a go kit, and believe me that kit made many times more money than it all cost. I actually wore-out stones which means I was sharpening a lot of knives and making a correspondingly good amount of money. The only problem with the edge pro is the amount of knives you can sharpen. The amount of business you can do is directly proportional to the number of knives you can sharpen. That and getting paid.

Enter the Tormek, Christmas gift from the wife. This machine doubled or tripled the amount of knives you can do, and changed the complexion of the business to where the sharpening took place in the shop and not on the road. Found it was easier to do a trade/replacement business as opposed to onsite service. The inventory increased but it was worth it. I did this for more than 10 years and then worked for the Feds for 15 more and retired. Needed something to keep me sane, so I went back to sharpening and dealing in tools new and used. Knives, Scissors (both Standard and highly technical Beauty shears and scissors), leather tools, luthier tools, hockey equipment, just not industrial tools (saws, end mills, drills, etc.). Getting to the point that I'm not doing much leatherwork, but I don't have to so I just dabble, and give some support to the Cosplay scene.

The Tormek is expensive, but I didn't pay for it either, another Christmas gift from the wife. For the average guy it might be overkill, but if you do wood lathe work, it sure is something. The availability of jigs for almost any tool (sorry no head knives) makes it really a go to item for those who can afford it, and all those jigs WILL cost you more than the machine. I can't do without it as people bring in tools that have been ground into something maybe bordering on obscene modern art.

Even with the Tormek, Makitas, the Bader, Burr-King, Powermatic, Edge-Pro, grinders, buffers, scissor machines, and everything else around here, it all can be done by hand with what amounts to various rocks, a little more technical than that, but not much.

So if anyones wants to discuss the technical side of sharpening, or the pros and cons of any sharpening system, let's hear it. There is every chance someone on here has used one of whatever has your interest. I am happy to expand on my experiences and to let you know if a particular tool spends most of it's time at the bottom of the unused tool drawer.

Art

[Oldtoolsniper]

Art,

What I've found is that most folks are looking for the easy, fast, foolproof way to obtain that razor edge with no investment of their own time. I have not yet found the easy way to sharpen anything that works for everything. I own the jet version of a tormek and even that takes time to learn to be able sharpen something on. The tormek jigs are nice and they cut down on the time needed but you still have to learn how "that tool" needs to be sharpened.

For my head or round knives I use a worksharp 3000, 1 X 30 belt sander, sandpaper on glass and or oil stones. It just depends on what I need to do. I just finished bringing a little W.M. Dodd 2 1/2" round knife back into shape all on oil stones. It was in rough shape and came from EBay. I'll never be able to remove the pits but they are not on the cutting edge so it's just cosmetics. I do the little ones this way so they don't heat up, there's not much steel to absorbe any heat.

What in your opinion is the easiest system for someone just learning with a slant towards leatherwork to become proficient at?

Some people won't ever want to learn how to sharpen anything and I completely understand that. As someone who did this for a living what would you charge for sharpening a round knife? No, nicks or anything required except sharpening from dull. I'm asking so there is a perspective for an investment in a system verses just sending the knife out to be done.

I'm also talking about tools that the ordinary leatherworker would be using. Basic, ordinary tools not the harder specilty steels that are out there.

If you were teaching sharpening leather tools as a class which tool would you teach first and why.

I'm asking all of this because I think you are on to something here that everyone on this forum can benefit from. We all need sharp tools. I also believe that even if you send out your sharpening to be done you need an idea of what to expect and what you are asking for.

Roy

[Art]

Hey Roy,

Wowzer! I'll try and cover it all, but poke me if I don't.

First off, I charge $10 and $6 shipping to sharpen a head knife. I'll only charge $6 to ship any number of them. Send me 100 and they cost $1,006 back to you. Kitchen knives are $5, and Hunting/Field knives are $8. Turnaround is 2 days sometimes more.

The easiest system is to buy a large piece of tempered glass, and have the edges finished. If you can get 4 pieces of sandpaper on it more the better. Just remember, tempered and finished edges. You can stick various grits of finishing sandpaper (like wet and dry) to these and use them as stones. Sharpen away from the edge as any bubbles or creases in the paper will stop you in your tracks. Get a tube of 3M Feathering adhesive #08051 for a 5 oz tube (it ain't cheap), make sure it is type II, and get 3M General purpose Adhesive Cleaner #08984 to clean it up. The feathering adhesive will allow you to peel and stick the paper, and if you don't let a bunch of crud get on the adhesive side, sick and peel it multiple times. You're going to spend $40 for both, but you'll thank yourself for that expenditure. You should get out your handy dandy protractor and cut yourself some wedges at 7.5°, 10°, 12.5°, 15°, and 17.5° to cover all the bases. With round knives, I do 10° per side for an included angle of 20° but some knives won't take a 20° included angle so you can go 25° or even 30° without sacrificing much sharpness. There are four quadrants to the head knife edge, sharpen each separately with the same grit, then move up through the grits when you have a consistent burr. Many ask why go up through many grits? Ok, sharpness is important, but polish is paramount in sharpening. Each stone or grit leaves scratches, from naked eye to 30X loupe and even higher. The edge bevel should be a mirror if possible. Some knives, not real possible, but a good hard steel can be polished, and most scratches can disappear. The edge will cut and part the leather and not make a lot of noise. Tradeoffs are time and cost. Stones and belts cost money and time is also money (except for maybe us retreads who don't really care). Then you get to the point of just how sharp can I get this puppy, (and the lightning strikes and the sharpener screams, IT LIVES) .

It goes up from here when we get into stones. There are books on sharpening, mostly woodworking tools, but it all kind of applies. If you want advice on a product, let me know, if I've used it, or it is just plain ill conceived or impractical, I'll give a fair assessment.

If I were teaching a class, it would be a lot of board work at first, about edges and profiles. Then I would teach the head knife and how to put each type of edge on it. If I can teach you to sharpen a head knife, then you are pretty much going to be able to sharpen most knives, but the second would be the concave edged knives, like some of the clicker knives. I think third would be edgers, although the tools required for that are small and can be quite expensive. A quality 3mm pilar file will cost $35, but a small piece of steel and sandpaper can accomplish as much if you are careful. Really, an edge is an edge and once you learn how to sharpen it, you just have to figure a way to get at it. Experience really really helps.

I hope this answers most of it, if you need more, let me know.

Art

[Art]

Let's talk a little about included angles. I like 20°, that is 10° per side. I will look at a knife and see if that is possible. On Bill Buchman knives, he used thin steel that I sharpen at 20°. I have a few of these knives and that is how I sharpen them. Note that the thicker the steel, the greater the angle they must be sharpened at. An old Rose or Osborne will need a lot more angle than a Buchman. I can never tell 'till I get the knife in my hand and see what steel, how thick, and very importantly, what the guy who came before me did to it. Remember all those wedges I told you to make? I wouldn't tell you to make a whole bunch of them if you only were going to need the 10° one. While I have and use vernier and digital protractors in the shop, I find this thing gets a lot of use.

While a lot of sharpening and edge mechanics may tell you they freehand it or eyeball it, the good ones don't.

Art