Frustrated "trying" to sharpen bench chisels

[Jeremy Gibson]

I have been working off and on trying to sharpen a new set of Marples Blue Chip bench chisels for about a month. Admittedly it has been more off than on, but today I gave it some more elbow grease. I have a piece of glass and sandpaper in 100, 150, 220, 300, 400, 600, 1500, and 2000 grits. At this point I am still working on flattening and polishing the backs.

The 3 smallest chisels are pretty good as of the 600 grit paper. Very shinny all the way to the front edge with a clear reflection. The 3 larger chisels are giving me grief. I either have a thin line at the front edge not getting flattened or a bit of the corner. What seem the most frustrating is how the scratches look even in the course grits and only show problems after getting to 400 or 600 grit.

I have to assume the answer is to keep going back to a course grit and work the back some more, but is there any advice out there in the creek? I have the glass on a piece of non-slip router mat, and then on a flat workbench surface. Is the mat a bad idea and should I mount it on a plywood base clamped to the bench?

[Michael Ballent]

What are you using to hold the chisel? I would ditch the router mat just because I would prefer anything not to move around on me. Have done the ink trick? You use a felt tip marker and "paint" the area that you are going to sharpen. Then as the metal wears away you will see any high/low spots. Other than that it's a pretty straight forward process.

[Don Baer]

I agree with Michael on this one. Loose the mat and use a magic marker. I sharpened my Marples in about 5 minute each using the scary sharp system. I happen to have a nice 12" square piece of marble that is 2" thick that I picked up at a leather craft shop so I use that instead of glass but I use the same regiment starting at 100 and working my way up to 2000.

[Travis Johnson]

Sounds to me like you are having the same problem I did when I first started the Scary Sharp method. You never mentioned whether or not you had a chisel holder or not. That might be the problem, an inconsistent bevel angle.

What I do is place my chisel in a holder, set the bevel and then start out with my lowest grit (in my case 220). After that, and without taking my chisel out of the holder, I flip it upside down and flatten the back/ take off the wire edge. I then go back and make a few stroked backwards only so that no burr forms. I then do that all the way up through my grits of paper (up to 2000) I then go an extra step further by stroping my chisels on a piece of leather charged with jewlers rouge, but that really is not nessassary.

I use a simple wooden jig to that registers my chisels at the same distance inside my chisel holder each time so I don't have to worry about changing my angles each time I sharpen a chisel.

As for my glass. I work for the railroad and found that locomotive winshields make the perfect glass for sharpening. They are 3/4 of an inch thick, laminated, heavy so they don't move around and are literally bullet proof, so I don't have to worry about a piece of glass breaking in my hands. Of course they are also free.

[Kevin Herber]

Jeremy, I feel for you. I am not a good sharpener either. I use the scary sharp method and have gotten 'fair to middlin' results. Questions I have are:

How big a piece of sand paper should we use? My piece of glass is 26 inches long and 5 inches wide.

What is the best sand paper and how do you attach it to the glass/granite?

How long of stroke do you use: 2-3 inches or the full length of an 11 inch sheet of paper?

How hard do you press the tool onto the sandpaper?

Do you lubricate the sandpaper? If so, with what?

Also, is the Veritas Mk.II honing gauge worth 50 bucks?

Thanks -- Kevin

[Ben Grunow]

On the job I sharpen my chisels with the belt sander (I can hear some of you cringing). Just take a firm grip and hold the edge against the wheel on the belt and apply gentle pressure until the edge is sharp and uniform. By this I mean that any dings and dents are removed and the cutting edge is square to the sides. This must be done carefully and slowly so as to not overheat the steel and cause it to lose its temper. After this process I will use a flat metal file to remove any burr that may have formed and then hone the leading edge and back with the diamond stone. Results are razor sharp. By that I mean that you can shave your skin or fingernail without applying any pressure. Scary sharp even. Sounds primitive but I have chisels that are 10 years old (and visibly shorter than when purchased) that I use every day and sharpen reularly. Someone always borrows them and chisels some concrete or a nail or something. Oh well, back to the belt sander.

[Jeremy Gibson]

Thanks everyone for the advise. I removed the router mat and noticed a significant difference. So far the glass hasn't shifted while honing, but I'll make a holder for it soon.

Travis, I have a chisel holder (grey clamp style until I buy the Veritas MKIIjig). The thing is I hadn't got to the bevel yet. I was still trying to flatten the back so no jig yet.

Kevin, from what I have read on the subject (as much as I can) I use wet/dry sandpaper if at all possible and sometimes use just a bit of water to lubricate. I have read about 50% that say to use it dry and do it sometimes. I try to take full length strokes, which can be 11" or 9" depending on the size of paper. The higher grits I got at an automotive store and are 9x4 sheets.

So now I worked the backs of all 6 chisels to 2000 grit and have started on the bevel. Thanks again to everyone!

[Michael Ballent]

Are you using the marker? That will really help you "see" what the cutting action is doing. Re-apply after every grit change :D

[Brian Hale]

I use a spray bottle with water and a few drops of Ivory dish washing soap.

Brian :)

[Lee Schierer]

Jeremy, I feel for you. I am not a good sharpener either. I use the scary sharp method and have gotten 'fair to middlin' results. Questions I have are:

How big a piece of sand paper should we use? My piece of glass is 26 inches long and 5 inches wide.

I use 1/2 sheets.

What is the best sand paper and how do you attach it to the glass/granite?
Aluminum oxide sandpaper from an automotive store. Garnet paper is almost a waste of time to use

How long of stroke do you use: 2-3 inches or the full length of an 11 inch sheet of paper?

I use full legth strokes. Stop to dust off the sheet every 8-10 strokes. Also wipe off the swarf from the tool with a dry soft cloth. Old tee shirts work well.

How hard do you press the tool onto the sandpaper?

I apply pretty firm pressure on the coarsegrits and slightly less pressure on teh finer grits.

Do you lubricate the sandpaper? If so, with what?

No. I sharpen dry. I also dust off the paper fairly often.

Also, is the Veritas Mk.II honing gauge worth 50 bucks?

I have trouble holding the angle steady by hand so I use the veritas sharpening jig. I think I paid $30 for mine, it is not their new deluxe unit.

Thanks -- Kevin


I hope these answers help. I use my hand tools much more now that I have learned how to get them sharp so they work well. It is a joy to see shavings coming out of a hand plane that are thin enough to read through. Good shavings should be about .001-.002" thick.

For you hand planes you will want to hone the sole as well. A mirror finish on the sole will make them slide easier.

[Kevin Herber]

Thanks guys. I'll try your suggestions and see what happens.

-- Kevin

[Pete Harbin]

My process is almost identical to Lee's. I use both sides of two pieces of glass. Two grits per side afixed with some 3M spray (77, I think.)

When I'm working on a particular grit, the sandpaper on the other side of the glass (face down) eliminates any movement.

Like Lee said, long smooth strokes, and brush the paper off after about 10 strokes. Don't wear a favorite T-shirt though...it will get a little grimey! :D
I also work the whole process dry. I did a full set of nine Marples Pro Touches, and then another "standard set" of 4 Pro Touches that I keep in my tool bag for any classes I take. (Taking Hand Tools in Santa Fe starting in August! Woo Hoo!) This system really works.

Pete

[tod evans]

jeremy, i`m a firm believer in no jigs. take the time to learn on what ya` got, oil or water stones, sandpaper-powered or flat, ect. it really doesn`t take all that long to develop a technique and once you do it`s like riding a bicycle. plus when you start acquiring carving chisels you`ll have half the battle whipped if you allready have a technique that works for you. .02 tod

[Travis Johnson]

Jeremy, I use WD-40 to flush the filings away, use automotive wet/ dry sandpaper and the same cheap gray jig that you mentioned.

[Maurice Metzger]

Jeremy, in my experience a lot of what you're going through seems standard for flattening the backs of chisels with sandpaper. It will seem flat on the rougher grits and then show non-flat spots when you move to finer grits. Moving back to the rougher grits is then called for.

If you have a belt sander there's advice here from Bob Smalser about using that to flatten the backs:

http://www.sawmillcreek.org/showthread.php?t=27953

I don't have a belt sander, I just spent the time with sandpaper and did get to flatness eventually. Later I used a 220 grit Norton diamond stone which was faster. I've worn that stone out so I'm about to try 3M 80 Micron Abrasive Film. If that doesn't work fast enough I guess I'll be getting another diamond stone.

Hang in there, it's all downhill once you get the backs flattened. A sharp chisel is truly a joy.

Maurice

[Joel Moskowitz]

THere is no reason to flatten the back of a chisel past the bottom 1/16 - 1/8"
as a matter of fact traditionally made western chisels were made with a slightly hollow back - on the grounds that it is much easier to get the bottom 1/16" of a concave chisel flat than figure out how to flatten a convex backed chisel.

Of course with old chisels and corrosion backs can be a real mess - but again just the bottom edge is really all you need.

joel

ps - if you do flatten the entire back of a chisel over time as you chase the burr and get rid of the burr you will end up with a convex back. I've seen it dozens of times.

[Clinton Findlay]

Jeremy,
Other then Lee's comments I guess I'll add:
That I dry sharpen, and use WD40 to clean out the swarf from the sandpaper once finished. This way the sheet of sandpaper is clean for next time.
I freehand sharpened for a fair while, but now I have the Veritas (LV) MII jig, I use that. Using the jig I get a quality job done every time, without fail.
I flatten the back of chisels and plane blades only abut 1 - 2" back from the edge, using sandpaper to 2000 grit and hang the rest of the chisel/blade off the edge of the 18" square granite block I use as a flat surface. (The polished granite cost me twelve beers 'nuisance money' to the local stonemason :) ) I flatten the back to 2000 grit first.
I have found that Scary Sharp doesn't produce as good a surface as a blade sharpened on the higher grit waterstone, and I'll be changing to that later.

I think that you might not be holding the chisel flat to the glass, there is a slight tilt due to the way you hold it, causing the "line" to appear at the edge or the corner. Maybe if you shifted the finger pressing down to the edge, as close as possible, and put the majority of the weight on that finger, as opposed to anywhere else on the chisel?
Either that, or you have worn a area of the sandpaper with the edge of the chisel, and there is a "low spot" due to a high degree of grit wear??

[harry strasil]

I wonder how the old time woodworkers got along without all the fancy jigs, 2000 grit stones and all the other hoopla, how did something as simple as getting a cutting edge on a chisel or plane blade etc., get so technical and complicated.

[Mike Wenzloff]

Cause, Harry, people, as a people, tend to go from the simple to the complex. It's in our nature. Just not all of us all the time.

I jump into these discussions from time to time. Usually to my doom.

While I tend to flatten beyond what Joel recommends, it is not scads more. Just easier for me to keep more on a stone.

And while I don't use natural stones, I do use graded waterstones, hence grit numbers. But even natural rock stones are graded, just not in grit sizes per se. I grew up using rock-based oil stones and prefer waterstones these days.

But whatever medium used for sharpening--oil, water, paper. Whatever method--jig vs. hand vs. power. Doesn't matter. The key is to learn to do it consistently to produce an edge of acceptable quality for the task at hand. And to really do no more than is necessary.

Take care, Mike

[Mike Henderson]

I agree with the spirit of Harry's posting. When I first started woodworking, I was anal about sharpening. But soon, I learned that when you use the tools, you beat up that beautiful edge. Since I wanted to spend more time woodworking and less time sharpening, I relaxed my standards somewhat. My tools are still sharp, but I don't obsess about it like I used to - I go by how they're cutting, and not how they look.

Mike

[Joel Moskowitz]

In a professional shop you follow the technique of your master. IF it doesn't work the first time you practice real fast until it is second nature or you find another job. With self taught people I think there is a tendency to meander through different systems without giving any system a chance to either sink in or enough practice so that the technique works.

[Steve Schoene]

The necessity for flattening a larger portion of the back is the common use of chisels for paring. Unless the back can lie flat against the surface you can pare in the same plane. Trying to flatten only the end 1/8th or even less in most cases would give a chisel back that would have to be lifted to cut, reducing the precision of paring significantly. (In essence, you have a knife, not a chisel.)

[Mike Wenzloff]

Steve,

That paring chisels have great flex negates--at least in part--the necessity of flattening them. Other than what is neccessry to obtain the desired edge.

But there can always be found exceptions. But personal preference goes beyond what is necessary.

I have yet to find as-used planes or chisels in the wild I would even consider reasonably flat according to my loose standards. Much more so on paring chisels and other tools often used by patternmakers.

Take care, Mike
unusally grouchy at the moment--so take the above for what it's worth.

[Joel Moskowitz]

Sorry I can't agree - for two reasons.
Because the chisel back starts out slightly hollow - flattening the tip just evens it out and doesn't make the chisel back convex. A proper western chisel will have a back similar to the hollow back of a japanese chisel except that the hollow will be a result of hardening, much much less promient (only a few thousands) but essentil because a convex back is impossible to sharpen properly. And of course if you have a perfectly flat back the next time you try to turn a burr or sharpen at all you will start creating a long convexity.

2 - more importantly in any chisel as it goes into the wood the bevel will force it down deeper. the user has to steer otherwise the chisel will dig in. THe main reason for a flat across the back is for sharpening - not for use.

I think the main problem is that tons of new uses get a chisel, try to flatten the entire back, waste a lot of time and steel, and never get a chance to see how the chisel performs with just a bit flattened.
I have seen hundreds of antique chisels, used by professionals over the centuries - long paring chisels where only the very tip was flattened competely. I have also seen dozens of new chisels flattened completly and in EVERY case I see a rounding at the tip - it's really hard to flatten a chisel perfectly and not round over near the tip.

joel

[Steve Schoene]

I don't think I've encountered a single convex back in a host of Buck Brothers, Stanley and other usable chisels.

It's true many older chisels have been used by carpenters where they are used as knives, not true chisels. How they were sharpened tells little about proper sharpening of a chisel for paring.

Certainly you won't avoid dubbing the tip using sandpaper for sharpening, but with properly maintained oil stones it isn't that much of a challenge.

I don't understand your reference to digging in and steering. Paring operations aren't meant to remove lots of wood, and the most common way I have ever done it is to lay the back of the chisel absolutely flat on the surface I want to pare the rest of the wood to be level with. A flat chisel making shallow cuts isn't diving anywhere, its slicing. But the end result won't be a flat surface if the back of the chisel isn't flat. The back of the chisel is the guide to the operation and is flat because of its use, not just for sharpening.

[Joel Moskowitz]

I don't think I've encountered a single convex back in a host of Buck Brothers, Stanley and other usable chisels.

Neither have I -that's my point they are made slightly concave

If you press the chisel flat at the bevel and it will go straight - no matter what happens to the chisel a little ways back from the edge. - try it.

[Craig Dempsey]

I finally "got it" about honing when I followed the instructions at Joel Moskowitz' site. http://www.antiquetools.com/sharp/index.html I am still not very fast at it, but at least I feel confident that with patience and attention I will produce a sharp tool.