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Learning to Sharpen

17K views 29 replies 12 participants last post by  MarkColan 
#1 ·
Intro and Goals

Introduction

I have mainly been a power tool woodworker, but at some point chisels and planes begin to seem useful. In particular, I don't want to buy a power planer.

I already had a small block plane and some chisels from my Dad, and one I bought, that need work. I never liked hand tools like these because they seem so difficult to use. Well, of course they are not, so long as they are properly sharpened, but I have never done that. I also own some nice kitchen knives that could be sharper and want to learn to sharpen them like a pro.

Obviously the time has come to learn to restore and sharpen blades. I have a Chinese dual-grit stone intended for kitchen knives, and no experience. So I started reading about various kinds of stones, the things you need to do to keep them flat, guides, and so on. Expensive, and inconvenient.

As I embark on tooling up for sharpening, and then actually trying to sharpen, I'll write here about what I learn. I would welcome any comments from those of you who are experienced with sharpening. Keep in mind that I am starting as an absolute beginner on the subject, aside from knowing how to use a steel on a kitchen knife.

Goals

  • Come up with a system that allows me to have a quick, usable edge without spending a lot of time and effort, so that I am inclined to do it regularly.
  • Know how to achieve a much better edge for delicate work, with extra effort, when required.
  • Avoid spending a lot of money on equipment.
  • Ability to restore damaged edges, when practical.
  • Learn to enjoy it so that I am more inclined to use hand tools.
  • Targets: Used plane irons, chisels, marking knives, kitchen knives. Maybe touching up router bits.

Non-Goals

  • Achieving the perfect edge. There is no such thing as perfection. The law of diminishing returns applies: I can put more and more effort into any work and get better, but at some point the improvements will not be worth the additional effort.
  • For now, I am not interested in sharpening saw blades of any kind or drill bits. When I need my table saw blade sharpened, I'll have it professionally done.

Note

I started something like this as an entry in hand-tools forum (right here). It had been awhile since I had written a blog entry, so I forgot to do it as a personal blog. Someone called me on this, and he's right: I should be doing it as a blog instead.

This entry and a couple that followed were discussed on the previous pages. I can't delete the old entries, but the blog will continue here.

Incidentally, my involvement with woodworking goes in ebbs and flows, owing to changing demands in my job. At the moment, it's flowing!
 
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#3 ·
Sharpening should probably be the first thing every woodworker learns Mark, but of course it usually doesn't work out that way. Anyway, I think you are wise to concentrate on this area. It will make your woodworking much more enjoyable and rewarding.
 
#4 ·
PurpLev

A local friend who I met on Lumberjocks, PurpLev, is more of an inspiration to me than he may realize. A few years ago, I needed help with some gluing cauls. His help came in the form of showing me how to sharpen my block plane, then using it to vary the thicknesses.

He did it quickly, and I did not pay close enough attention to really learn. But in his show, he has planes of several types, plenty of chisels, and does a lot of work with hand tools. At the time I met him, I had no interest in becoming a hand tool expert; I use mainly power tools.

But since then, I have learned about the importance of planes, and bought a set of used (somewhat old) Stanley planes from Hull's Cove Tool Barn, with the intention of eventually being able to flatten my slightly cupped bench top, and in general use planes more in my projects. Someone suggested that I get a #4 smoothing plane, a #5 jack plane, and a #7 jointer plane. I got a #3 instead of a #4. The price for a #3, #5, and #7 plus a shoulder plane was about $200 total.

And I do struggle with my chisels, dull as they are. I have tried to sharpen them with a few strokes on a cheap abrasive block bought in a Chinese restaurant supply with useable results. So if that's possible, with so little effort, then perhaps with just a bit more effort I could have better performing blades.

Anyway, this blog is dedicated to PurpLev, who without saying anything, nudged me in the direction of using hand tools.
 
#5 ·
Brent's Sharpening Pages

Somewhere someone mentioned Brent's Sharpening Pages. I like the idea of starting simple, so this appealed. I thought it would be a cheap way to start. It's not, exactly, though it is less than the stone and guide approach.

Overview of Brent's System

In a nutshell, Brent's system relies on two kinds of jigs. First, there is a piece of glass with abrasive film attached via adhesives. The glass is glued to masonite, and the masonite will have a non-skid material on the bottom so it stays put in use. He recommends three grits, so there are three glass jigs.

The second jig is a guide designed to hold plane blades, chisels, etc at the correct angle. Brent tells you all about how to make them, as this is really the heart of his system. He suggests making guides specific to the width of the blades you sharpen. I have not studied or made them yet, but I think he has a different guide for chisels.

Materials

I ordered the glass at a glass store. I figured 1/4" plate glass would be better, until I got a price on four 6×16" cut pieces and it was like $92, because they had a minimum piece price for 1/4" glass. They also have a minimum of $5 for 1/8" glass (total $21.25), and I went for that. I don't have much experience with glass cutters, but I think I could have done better had I taken the time to shop around.

Brent recommends Weldbond for the glue. It does not seem to be available locally, and I wanted to work on the project this weekend, so I used a glue called E6600 clear medium viscosity that I got at an arts and crafts store. It was just over $7 for a tube and I used most of it. It specifically includes glass and wood as materials it glues.

He suggested some kind of non-slip fabric for the bottom. No experience here, but the hardware store had this rubbery (actually latex, I think) lacey stuff that is designed to put under carpets. It was about $8 for a 2×4' piece.

Last, the abrasive films. Probably not available locally, but I got a basic supply from a place in NY delivered Friday when I ordered Wednesday. Brent recommends three grits: 15, 5, and 0.3 microns, and he recommends the kind with self-adhesive backing. The place sells a package with two sheets each of those, and since the 15 micron is said to wear faster than the others, I ordered some extra of that grit.

I had a scrap of 1/4" masonite big enough to make the protective bases for the glass.

Assembling the Glass Plate Abrasive Jigs

Brent recommends sanding the edges of the glass because it can be sharp from the glass shop. In my case, the glass did not seem sharp, almost certainly because the glass cutter sanded them a bit, but I sanded them more and rounded the corners anway.

I cut the masonite to size, about 1/2" larger than the glass on width and length, to have 1/4" borders around the glass. Brent does not tell you how big to make it. I had meant to make it a bit extra long so I could put a hole in the top to hang on the wall for storage, but due to operator error, when ripping to length I had the wrong setting.

Next step was cleaning the glass before gluing. He did not say to do that, but for appearances and adhesion it seemed like a good idea. Then I put glue on the perimeter of each piece, a line down the center the long way, and three lines dividing the other way into equal sizes. I then attempted to spread the glue with a scrap, then pressed the plate onto a board.

The E6600 glue is not as viscous as I had hoped: it did not spread well. Perhaps Weldbond spreads better. They are different glues; in particular, E6600 is clear out of the tube, and Weldbond comes out white but is said to dry clear.

The critical thing is that the glass stays flat. Pressing it to spread the glue could cause it to be slightly uneven. However, it cannot flex much the narrow way, which is the more critical dimension; flexing the long way is probably not a problem for even sharpening. Also, I suspect that since the glass wants to be flat that it will even itself out a bit.

You may think I'm worrying about nothing, but I figure if tolerances of 0.3 micron (the grit of the finest film) are at stake, that would be the maximum unevenness I could tolerate, and probably I need much flatter than that.

Brent suggested taping the corners to prevent drifting while it's starting to cure. I used masking tape to tape two opposing corners for each board. I glued the backing on each.

Progress?

Work intervened, and I got as far as gluing glass to masonite, but have not tried it out. There will be a progress update soon. Meanwhile, a sharpening workshop was offered at Cambridge Center for Adult Education. I took it and learned a lot.

I will include pictures in this work, but for now, there's just text. Thanks for reading.
 
#10 ·
Ron Hock - The Perfect Edge: The Ultimate Guide to Sharpening for Woodworkers

Noting the good reviews on Amazon, I got a copy from the library, then decided it was a good ref book for my woodworking library, so I got it from Amazon.

The author, Ron Hock, is a well-regarded blade maker, founder of Hock Tools. He knows a lot about the kinds of steel available for making blades, and talks about how to sharpen blades of many types.

Pros:
Everything you could want to know about blades and sharpening them from a guy who knows first hand
Excellent reference for the intermediate or advanced sharpening fan chasing the ever-elusive "perfect edge"

Cons:
Overwhelming for a beginning who is just looking for a simple way to get started

This is a book that I am reading some as I learn to sharpen, but suspect it will serve be better when I get better at sharpening. It's a book I will have to grow into, as it is very advanced for where I am now.

The teacher of the sharpening class I took recently immediately recognized the author's name as a famous blade maker and exclaimed "He's the MAN!". I don't think he had seen the book before, because he spent some time looking at it during the class.
 
#11 ·
Sharpening Class: chisels

"When the Student is ready, the Teacher will appear."
Buddhist saying

Joan found a class for me in the Cambridge Center for Adult Ed catalog on the subject of sharpening blades and scrapers. It was taught by a wood artisan, Dan Paret, who uses mainly hand tools in his work. As it turns out, we are friends with him and his wife, though we have not seen them in a few years.

Even though I have not completed my experiments with Brent's methods, I decided to take the class. It was six hours on a Saturday for $130 and recommended bringing one new chisel and one new scraping card. I brought in my old used chisels and plane irons, but only really got to sharpen two planes. Kind of what I expected. The rest I can do at home for practice.

Dan has been teaching various woodworking classes at Cambridge Center for Adult Education in Harvard Square for 13 years. A guy in the class has taught portrait painting there for 15 years. As it turns out, I taught there for 10 years, too, from 1983-1993: Thai cooking.

Dan's approach is to keep things as simple as possible so that one is more inclined to sharpen more often, thus using tools that are more sharp. He suggests that sharpening more often is less work than starting from tools that need correction.

Overall, learning by reading makes as much sense for sharpening as for dancing: it's really hard to get it right without a teacher showing you some techniques, although anything you make up that works is just fine, too. This blog entry is as much for my future reference as it is for others to learn from.

Sharpening Blades

He said the most important thing in sharpening blades is the word FLAT. Flat backs, flat tops, no rounding. The exception is his technique of using a power grinder to create a hollow on the bevel side. More on this later.

Equipment

Like Brent's Sharpening pages, Dan uses abrasive sheets on glass, rather than oil stones, water stones, etc. Unlike Brent, he uses no water or oil on the sheets, and uses sandpaper rather than film.

He has glass plates mounted on masonite with 320 grit sandpaper on the top via adhesive, and 80 grit on the bottom. The top sandpaper is only to provide resistance for sharpening sheets placed on top, which are not glued down; he never uses the 320 that he glued down to sharpen, so there is no need to replace it regularly. He said that 320 is the coarsest grade he has found that will not telegraph its grits to the paper used on top of it. The 80 grit on the bottom is to keep the glass plate and its masonite from sliding on the bench.

He uses 9×11" sheets of sandpaper cut into four 2 3/4" strips, grades 220, 400, 1000, and 2500 when sharpening new blades. He uses 120 or 150 for blades that are seriously unflat on the bottom.

A 6-inch grinder with #36 wheel running at 1200 RPM (or less) is used for grinding a hollow into the bevel face, see below.

Cleaning the Blade

If the chisel or plane iron has any oil or grease on it, wipe it clean with denatured alcohol.

Flattening the Bottom

He suggested that we start by flattening the bottom. One could also start by sharpening the bevel (see below) in some cases.

He put a strip of 220 onto the 320 paper on glass (see equipment, above) then held a chisel perpendicular to the strip, using fingers of both hands to hold it (don't try to hold it with the handle). Then, make strokes for the length of the sandpaper by moving your body, not your arms. Hold it flat while doing this. You only need to do this to the first inch of the blade, but no harm in doing more. You're done (about 30 strokes for a new chisel) when the sandpaper lines you put in it are the only thing you can see - no other lines from the original.

This was then repeated for 400, 1000, and 2500. The 2500 gave it a near mirror finish, but he cautioned us that shiny does not mean flat, and flat is what is needed.

Grinding a Hollow in the Front Bevel

I've never heard of this before. He suggests using a slow-ish grinder (1200 rpm or less) and a 36-grit 6 inch wheel to grind a bevel. You need an angle guide such as the Veritas one to do this well. You want to adjust the angle so that the initial hollow is midway between the cutting edge and the end of the front bevel. To find that: estimate, flick the motor on then off, and move the chisel into the slowly-moving wheel, just enough to find out where it touches. If it is not in the middle, adjust, try again, and repeat until centered.

Now turn on the motor. Feed the bevel to the wheel until it just touches, with the edge of the chisel in just a bit from the edge of the grinding wheel. Using your fingers as a guide on the bottom of the angle jig to maintain the amount of the feed, move it from right to left and back, once, and stop. Avoid overheating and thus losing temper. It's easy to overheat an edge if the edge of the bevel is near the edge of the wheel, so avoid that. If it starts to get hot, dip in water then wipe off.

You want to continue doing this until the hollow goes all the way from the edge to the end of the bevel. Look at the edge under a bright light. If it reflects (you have to turn it to find it, but try perpendicular to your face), then it's too thick, and you'll spend too much time honing. Repeat the grinding procedure above until you cannot find the edge, because it is too narrow to reflect light back at you.

Why? Two reasons:
  • The hollow makes two raised edges at the ends of the arc that should both be in contact with the sanding paper with equal pressure. This serves as your guide while honing.
  • If you are restoring a chipped blade, you will start by jointing the edge flat, and the result will be an edge thicker than a screwdriver. So grinding a hollow means you have a reasonably good edge before honing.

Honing the Bevel

Put a piece of 220 on the 320-faced glass sheet. Make about four strokes (two up , two back) the entire length of the sandpaper, holding the hollowed bevel so that both ridges at the ends of the hollow are in contact with the sandpaper. Hold the chisel with your fingers and thumbs, with the blade 90 degrees from the length of the sandpaper strip you're using. Keep the angle of the chisel to the glass surface the same while you do it; avoid lifting the chisel handle, which will round your edge.

Check for a burr on the back. When the burr is even all the way across, you're done with 220. Now repeat with 400, 1000, 2000.

He does not use jigs to hold the angle. Instead, he grinds a hollow using a 6" grinder, and the edges of the arc are used as a guide. The downside is that eventually you will sand away the arc and have to hollow it again.

It is tricky to hold the blade just right while honing. For this reason, there is an infinite parade of jigs, commercial and shop-made, for holding the blade at a constant angle. I think the hollow shoulders work fine for chisels, but since a plane iron is much thinner, I'll make some of Brent's guides.

When finished, turn the chisel over and give it a few couple of strokes at 2500 to remove the burn, then test the chisel.

Restoring a Chipped Blade

I had a chisel in sorry shape. I don't know where it came from, but it represented a good challenge. It had a pretty good chip in the blade, and the metal was rough from a bit of corrosion (dirt, a bit of paint, some light rust, but not deep rust).

I started by sanding all surfaces, going 120-150-220-400-1000-2500 - the back, the flat of the front, the side bevels, basically all edges except the front bevel itself, which I left as it was.

Then I fed the chisel into a dressed 36-grit wheel at 1200 rpm, checking it to see when the chip area was flat again. Made sure it did not get to hot by pausing or dipping from time to time. Eventually, the chip was gone (checked with a square, also to make sure it was at a right angle with the blade), but the cutting edge was about as thick as a blunt screwdriver. That will last a real long time that way, even with hard strikes, but it won't cut very well. Creating a hollow, as described above, was the solution. It took time and patience, but eventually the cutting edge was too thin to reflect light.

By the way, Dan didn't teach me this: I just figured it out and did it after sharpening the first chisel; I wanted more of a challenge. He said that if there is a secondary bevel on the back of a chisel, it's best to restore flatness using the method above, rather than trying to sand the back flat.

Next Time: Turning a New Burr on a Scraper

Aside from chisels, he also taught how to sharpen and use a scraping card, using a burnisher, flat file, and 1000 / 2500 sandpaper. I'll talk about that next time.
 
#12 ·
like anything - practice makes perfect. the hollow grind is a great way to get a "jig" for practicing with as it aids in keeping the blade at the desired angle. once you get the hang of it and the muscle memory to sharpen it freehand like that, hollow grind or no hollow grind you'll be able to sharpen freehand more easily.

if you do run into issues of the blade snagging or tipping over/under, try rotating the blade 45 degrees to the line of motion that will give you less forces against the bevel that could tip it off of it's angle.
 
#14 ·
Highest Grit for Sharpening?

How high a grit one should one use when sharpening? Some people sharpen with a 1000/8000 water stone. There are 12000 and even higher grit stones out there - though I have learned that the grit rating scheme is not always consistent, so that a 12000 is not necessarily finer than a true 8000, for example.

In the class I took this weekend, the grits were: 220 400 1000 2500. For a chisel whose back was not flat, and 220 was taking too long, the teacher suggested 120 or 150. And for damaged chisels (one with a chip in the cutting edge), I used a 36-grit wheel on a 1200 rpm grinder. The latter, when taken through the paces, yielded a beautiful looking, but more importantly, SHARP chisel.

A reason for going to 2500 or higher is the satisfaction of the nice mirror finish, but I'm not convinced that it makes a huge difference in cutting wood, and I doubt it makes the edge last longer.

Before taking the class, I occasionally used a cheap combo stone that I bought at a Chinese restaurant supply, really intended for kitchen knives. The two grits are probably in the range of 200/400, and I have always used it dry. It does not provide a mirror finish or anything close, but it did greatly improve the usability of my chisel, without going to higher grades. And I sharpened only the bevel side, because I didn't know better.

Now that I know better, I am certain I will get a better edge, but it will be at the cost of some additional effort. With sharpening, there is this law of diminishing returns, where additional effort does not give that much improvement. For me, I am looking for the sweet spot between not too much effort and yet sharp enough for my purposes. But it isn't much extra effort to go to a higher grit or two than necessary, and it looks sweet when you do that, even if the additional sharpness is mostly theoretical after the first use.
 
#19 ·
Sharpening Class: Cabinet Scrapers

Turning a New Burr on a Scraper

In the sharpening class, he also taught how to sharpen and use a scraping card, using a burnisher, flat file, and 1000 / 2500 sandpaper. He had people bring new scraper cards to class, remove the bur, and pull a new one. I forgot to bring mine, so I asked him for the class card (he has a box of them for use in other classes) that needed the most work.

Equipment
Burnishing tool, flat file (flat side of medium hald-found, or a flat bastard file), strips of 1000 and 2500 sandpaper, flat surface (ideal is 320 grid paper glued to a sheet of 1/4" glass; the 320 grit is not used other than to keep the 1000 and 2000 paper from slipping during use).

For safety, consider wearing some tough gloves. It's easy to run a corner or edge on the skin of your hands and give yourself a good cut.

Boraxo soap for cleanup. Tuning a scraping card is dirty work.

Clean the Scraper

If the scraper has any noticeable amount of oil or grease on it, wipe it clean with denatured alcohol.

Removing the Existing Burr

Lay the card flat. Use a burnishing tool, placed flat on the card and perpendicular to the edge, moving it back and forth a few times to flatten the bur.

Flattening the edge

Put the card in a vise that has wood pieces over the jaws, fairly tight. Use a flat file (such as a bastard file) to file the edge. Carefully hold the file perpendicular to the edge, while orienting it so that you get as much contact between the abrasive part and the edge as possible (not quite parallel). When filing, you can tell when the rough, uneven parts become smooth; stop when the resistance is even.

Sanding the Faces

To remove any burr from flattening, and to smooth the face, rub each side on 1000 paper strips on the glass plate a few times. Best is to do a little more than half of the face, holding the card with your fingers, the long way, then turn 180 degrees to do the same to the other side. Now turn the card over and repeat for the other side.

Reburnishing the Square Edge
Put the card back into the vise. Using the burnishing tool, held perpendicular to the face, press and rub about four passes (each stroke, up, or back, counts as one). Be careful of your fingers near the corner.

At this point you should have a card that is smooth and has no burs. The long end should be square, ready to turn a bur.

Turning the Burr

Now tilt the burnishing tool up to 15 degrees (low for gentle scraping, 15 is aggressive scraping) off of perpendicular on one side. Starting just below the corner, and applying pressure from the burnishing tool onto the edge, pull the burnishing tool along the length with even pressure. Repeat 2 or 3 times. Check the burr by using your nail, pulling gently up to feel it. There should be an even burr the full length.

Tilt the burnishing tool in the opposite direction and repeat for the other square edge. Now take the card out of the vise, turn 180 degrees, back in the vise, and repeat for the other two edges.

The ideal burr gives a consistent amount of scraping over the length of the scraper. If you didn't get it right, you can always start over from the beginning. Burnishing too many times will weaken the burr and eventually make it fall off.

Clean Up

You'll notice a lot of fine black powder around. This would be a good time to clean it up, then wash it out of your hands with Boraxo or lava soap.

This is the last entry discussing what I learned in Dan Paret's class on sharpening.
 
#21 ·
Flattening the back of plane irons

I recently bought used Stanley planes #3, #5, #7. I think only the #5 had ever been properly sharpened, as I could see the factory grinding marks. I doubt the #7 has ever been used.

The #3 in particular had problems: pits and scratches in the base (which required light sanding off a burr), and the blade had pits in the bevel and on the back. The back also had a ding area about 1/2" x 1/4", basically a shallow depression in the metal.

Learning to sharpen also instructs me on how to select used planes in the future!

The sharpening technique I learned (see notes on the class, earlier in the blog) started with 120, set on top of a piece of glass to which a 320 paper has been glued (only for holding the paper on top in place).

The teacher said sometimes you might go to 100 if the blade has problems. Well, I made only slow progress with the 100, so I tried 80, then 60. I did not want to use 60, because I know it makes deep scratches that you need to work up through the papers to get rid of. But even with 60, it took a long time to flatten the back.

As for the bevel, well, I figured it was a lost cause without a grinder. But I don't have a lot of skill regrinding the bevel, so I have to learn by trial and error. The good news: I do have the Veritas grinding tool support and blade jig.
 
#26 ·
Grinding to set a new bevel for a plane iron

The Problem

All of my plane irons have a bevel. Presumably it is close to the original 25-degree angle. But after flattening the backs, the next step, grinding and honing the bevel, wasn't working.

The problem I was having seemed to be that the tip of the edge was not getting honed. After a good bit of grinding with a coarser grade paper, I noticed that the other edge of the bevel (let's call it the "heel"), opposite the tip, had the grinding marks. I surmise that this is because the angle of the bevel is greater than the angle used by my sharpening jig.

My Equipment

For abrasives, I am using #320 paper glued to glass, and then a variety of papers set on top of the #320 for grinding and honing, the way I was taught in the sharpening class I wrote about a few entries back. For the jig, I made one with 1.73" height from Brent's sharpening jig instructions.

Technically, the two layers of paper changes the geometry slightly, thus the recommended blade extension from Brent's calculator could be thrown off by the additional height. But while that is true, I think the amount of the change is small, and I note that the accuracy of Brent's calculator is only to the nearest 1/32" of blade extension, which is potentially a bigger error.

I am using a Porter-Cable PCB8575BG variable-speed 8" grinder with its original wheels. The specified speed range is 2000-3450 RPM.

I also invested in a Veritas bench grinding tool rest some time ago. While I was nervous about setting a new bevel for my blades, mainly because plane irons are considerably thinner than the chisels I have set bevels for in the past, with trial and error I improved my technique and got a suitable new bevel.



Learning from My Mistakes

Here are some of the errors I made and what I learned by making them:
  1. It was easy to overheat the blade, resulting in black/blue marks at the edge where it contacted the grinding wheel, which represents places where the blade has lost its temper, thus getting software. There are three ways I know of to address this. First, dip the blade into water to pull out the heat. But for a wide blade, the blade does not get into the water fast enough. Second, noting that the most common location of the burn is at the corners, move the blade more quickly as I start, and as I finish, to reduce the time this area is in contact. Third, noting that it was the grinding time and repetitions that caused the burning, use the coarse wheel instead of the medium one I was using. Because fewer grains of abrasive contact the blade, it does not heat up as fast; also, it does not take as long to work, so I can move more quickly and use fewer repetitions. My grinder has a minimum speed of 2000 rpm. For grinding blades, a slower speed would be good. See below.
  2. Having achieved a bevel, I used a square to check the blades squareness, and by drawing a thin pencil line, found that it was not square. Realign the grinding tool rest to the wheel, and make sure that the blade is snugly against the guide pins, indicating proper alignment to the jig.
  3. Having achieved a square bevel, I found that the heel of the bevel, not the edge, was getting ground when using the jig. This is because the grinding angle is greater than the angle using Brent's jig, and requires adjusting the tool reset to a narrower angle and starting over. Though I used the angle jig included with the Veritas grinding support, it gave me angles that were too steep, so I adjusted freehand until I found an angle that works.

It took a long time, but eventually I got the ducks lined up - a setting of the Veritas grinding support to get a square edge and a narrow enough angle, and a technique that ground the blade with minimal burning of the corners of the bevel. I knew I was there when I started honing with Brent's jig and saw that the tip was being honed instead of the heel. It was down hill from there.

A Slower Grinder?

Now, what about the speed? My variable-speed grinder has a minimum speed of 2000 RPM, which is still fast for what I am doing. I am trying a couple of solutions.

First, I ordered a speed control from Amazon. I'm not convinced this will help, as this control only works for motors with brushes, and I am not sure my grinder has that kind of motor.

Second, my original grinder was one I found on the street, not far from someone's trash: what appears to be an old washing machine motor with a grinding wheel attached to it. No switch, and power attachment points are exposed! I got that and an assortment of wheels by just taking them. It appeared to be a giveaway (I do this from time to time myself). Now I think that motor DOES have brushes, so the speed control should work on it. I am thinking of building a specialized grinding setup using this motor and its wheels, and a shop-built stand set to a fixed angle of 25 degrees. If/when I do, I'll report in this blog.

Last, I found a vintage human-powered grinder on ebay, and got it for about $28 with shipping. Since I am working with hand tools, a human-powered grinder seems appropriate. It has not arrived yet, but I'll blog about it later.

Help me out!

I would welcome comments on this entry, whether what I think I learned was correct, and whether there are better solutions than what I have tried. Thanks for reading!
 
#27 ·
Grind the bevel on the grinder, then learn to free hand on the paper ( eventually moving to a stone). Then you can follow the hollow grind and there is no worries about a minor discrepancy in angle. Plus its faster and cheaper.

My honest opinion, you're putting to much thought and precision into a process that does not need it.
 
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