Posts Tagged With: Hand Tools

Some Thoughts About Flattening Your Tools


Much has been written about sharpening.  I’ve contributed to this mass of sometimes-confusing, often-contradictory literature.  As a frequent instructor on the subject, I have some modest experience with the successes and failures of those learning to tune up their edges.

If any part of sharpening can be called fun, flattening is the least among them.  It is certainly the most time-consuming, and it can be one of the most frustrating aspects, as well.

In earlier posts on my blog, I have recommended that students begin their flattening with a known quantity:  a true, flat reference surface.  Some students listen and take the plunge, purchasing a granite test plate, or one of the more expensive diamond lapping plates, also known to be flat.  Others, for a myriad of reasons, choose to use a piece of glass, or a broken  counter-top.

Many folks believe that these surfaces are fine to use for flattening.  Float glass, in particular, is called the “flattest” glass.  As often as I have looked, I can’t find a definition of “flattest”.  Flatter than what?  The old rippled glass from the late 1700s?  Flatter than a stained glass window?  I just don’t know.  Same for a piece of countertop.  I haven’t found a standard that defines when granite is flat enough to be called a countertop, and if that standard implies true “flatness” the way we need it for sharpening.

I’ve seen folks try to flatten their stones using a small DMT plate, with the long dimension of the DMT held at right angles to their water stones.  If ever there was a sure bet to dish out (or round over) the water stone, that’s it. I’ve had students use all kinds of surfaces as their reference, trusting that these are indeed flat.  Many of these same students are dismayed at the condition of the backs of their tools during the flattening process.

Why does this matter?

It matters because flattening is (at least) one-third of the sharpening process.  The steel from the back of the tool makes up half of the cutting edge.  And creating a true, flat surface on the back of a tool is the only action we can perform to guarantee a tool works the same way, sharpening after sharpening.

It matters even more because of the time you spend with your stones and your tools.  Even a well-manufactured tool takes a while to polish.  A less-expensive tool might take hours.  How frustrating is it to work on the back of a tool, obtain a uniform scratch pattern (one of the telltales that our back is as flat as the abrasive), switch to a finer abrasive, and then discover that you’ve still got a hump or a hollow on the back?  If you make this scary discovery, you are left with few options.  You must make the correction at this point.  All of your previous effort must be corrected, and if you don’t make the correction at this point, all your subsequent work will be wasted.  So you go back, flatten your coarse stone on your reference surface, and try again.

But what it the reference surface itself is the culprit?  What if there is a hollow in it, or a hump?  Then you’re creating the opposite sort of defect in the stone, and your tool will never, ever be flat.

So, back to the beginning of this post.  If you’re using glass, or a counter top, or any other “pretty flat” surface, you’re taking your chances.  It matters not that float glass is “the flattest.”  What matters is how flat your piece of glass, or granite, or steel, or whatever, really is.  Unless you know the answer to this question, you take the chance that all of your efforts at obtaining a flat back will need to be redone.

This is why those of us who sharpen a lot, and teach others to do so – make the recommendations we do.  It isn’t so our students run out and buy something else to clutter the shop.  It’s a lesson most often learned through the painful experience of having to re-flatten tools because we didn’t listen when we should have.

_______

Jeff Zens owns and operates Custom Built Furniture in Salem, Oregon.  He is a frequent woodworking instructor and writer.

Categories: Woodworking | Tags: , , , , | 2 Comments

Grinding by Hand – The Old-Fashioned Way


One of the woodworkers who has shaped some of how I work is James Krenov.  His sensitivity to wood and his approach to harmony in design and construction are elements I try to incorporate into my work.  His respect for tools is another.  His approach to sharpening was straightforward, and not fussy.  When tools needed a new hollow, grinding was often done by hand.   I started using this grinder setup when I got tired of the noise, dust and heat created by the benchtop grinder, and the setup time of a Tormek.  While I still use both of those tools when I need to, I turn to this hand-cranked grinder setup much more frequently.

After much wailing and gnashing of teeth in their editorial meetings, the editors at Fine Woodworking and at Popular Woodworking all decided not to publish this article.  One could speculate that it wasn’t “sexy” enough, or that it didn’t help to sell tools made by their advertisers.  Maybe taking hand tool use to this degree is just boring, Who knows.  But in response to a bunch of requests, mostly from students, but some from the blog, here are plans to my little hand-cranked grinding wheel.

Get the Grinder and Wheel First

Let me say at the outset that there is nothing magical, and nothing cast in stone, about any of the dimensions for this set-up.  To the contrary, it is really important to have both the grinder and wheel available before making any of the parts for this contraption, because the grinder/wheel combination might demand modification from the sizes presented here.  I purchased the grinder on eBay.  You need to ask questions before you buy one sight unseen.  You’ll want to know the maximum wheel size (which you often cannot tell from eBay photos) and how true the arbor runs.  If there’s a lot of runout on the arbor shaft, the wheel will wobble and you will need to correct for that.

When I fabricated this base, I worked off of dimensions from the grinder, rather than from a plan.  The point of all of these “disclaimers” is for you to be careful and think through your own setups before you start cutting materials, because the dimensions might need adjustment.

The Parts

The base is simple: a piece of 3/4″ Baltic birch plywood, 12 inches square.  It would make sense to add a cleat to the bottom so the grinder could be clamped in a vise, but because I travel with this grinder,  it needs to be flexible enough to work on any bench I might encounter.  So I simply clamp it to a bench top using hand clamps or whatever happens to be available.

The Base and the Tool Rest Block

The tool rest block is a laminated block of wood that measures 3-5/8″ x 3-3/8″ x 4-5/8″ before any shaping is done.

The Tool Rest with Pivots

The Tool Rest (top view)

The tool rest is another piece of Baltic birch plywood, cut to 6″ x 3-1/2 “.  The front edge (facing the wheel) is beveled at a 45 degree angle to provide clearance for the wheel.  There is a 1/4″ deep groove cut along the top front edge, precisely parallel to the front edge, in which the tool jig slides.  The width of this groove isn’t terribly important – you’ll cut a piece of 1/4″ MDF to slide in the groove, and you can fit the MDF to the groove fairly easily with a hand plane.

The tool rest pivots on two pieces of 3/4″ Baltic birch plywood that are let into dados cut in the bottom of the tool rest.  The pivots are shaped to fit the pivot point on the tool rest block.  I attach the pivots to the base with a 3/8” carriage bolt, secured with an adjustable handle with a female threaded insert sized to the bolt.

Setup and Use

To use the grinder you will need to square the tool rest to the wheel.  I use an accurate square for this purpose, and periodically check that tools are being ground square.  I square the front edge of the tool rest to the side of the wheel, and once in a while I dress the grinding edge of the wheel so it is square to the sides.

The Finished Assembly

Squaring the Wheel to the Tool Rest

Basic use is straightforward.  Be sure you wear eye protection, but I have not found hearing protection to be at all necessary with this setup-it is quiet, which is very appealing to me.  Rest the tool on the base, and support it on the side with the jig.  Get the wheel started and grind gently.  Using light pressure on the wheel makes it easier to spin, and reduces the risk that you will blue the steel.  Yes, you can burn your tools even with this grinder, so be cautious.   When you feel the steel heating up, give it a rest, or quench it in some water.

The Tool Jig (MDF) In Place on the Tool Rest

The Grinder in Use

Advanced users might grind on this wheel freehand – without the tool jig, just letting the groove in the tool rest guide your fingers.  Grinding freehand permits slight adjustment to an out-of-square condition and also facilitates grinding a slight camber if you want that on a plane iron.  Don’t try this right away – get used to cranking with one hand and guiding the tool (using the tool guide) with your other hand.  Once that’s comfortable, try freehand grinding.

Since I am right-handed, this setup is designed for me to crank with my right hand and grind with my left.  That might sound counter-intuitive, but it works pretty well once you get the hang of it.  Southpaws might want to reverse the orientation of the support block and grinder to permit left-handed cranking.

I’ve produced a fairly accurate SketchUp model of my setup.  Unfortunately this blog does not have the capability for me to simply upload the file for your use.  I’ll be glad to email it to you if you’re interested; just drop me a line at jszens@custombuiltfurniture.com.

Once you’ve got the hollow restored on your chisel or plane iron, you can get to work honing the tool and get back to your project.  If you haven’t read them already, posts that describe the honing proccess begin here.

_______

Jeff Zens owns and operates Custom Built Furniture in Salem, Oregon. He is a frequent woodworking instructor and writer.

Categories: Sharpening, Woodworking | Tags: , , , , , , , , , | 5 Comments

Book Review: The Perfect Edge, by Ron Hock


Ron Hock, renowned blade maker in Fort Bragg, CA. can now add “author” to his long list of credentials.  His recently-published book on tool sharpening, The Perfect Edge The Ultimate Guide to Sharpening for Woodworkers (Popular Woodworking, $29.99 cover price) offers a lot of conventional thought on sharpening, with some updated sections on abrasives and a very good discussion about steel.  A woodworker who doesn’t know how to sharpen tools won’t be any more proficient at the end of the read, but this book offers a nice overview of the theory, mechanics and technology available to today’s woodworker.

A Steel Primer

The Steel chapter is informative, but goes off track just a bit, in my opinion.  I don’t think a woodworker can know too much about steel, considering how much we depend on it.  Hock does a good job explaining the various steel formulations and quenching systems and offers good insight into the heat-treating process.  Where I found it bit off subject began with the discussion of the chemical process of rusting.  Hock follows this with a half-dozen pages of rust prevention and removal.  I don’t think I’m selling woodworkers short by assuming that this brief prevention message would do: “Keep your tools dry.  If they get wet, dry them off.”

In addition to the chapter on steel, there is a discussion of the how and why of cutting wood.  Borrowing heavily from R. Bruce Hoadley’s definitive work Understanding Wood: A Craftsman’s Guide to Wood Technology (right down to a striking similarity in the line drawings), this chapter covers some of the physics behind the interaction between tool and wood.  Some readers might question the relevance of this information but the more a woodworker understands about the relationship, the better-prepared he or she will be when it’s time to step up to the sharpening station.

How Much Can You Spend?

There is no shortage of information in this book about the huge array of jigs, holders, accessories and  machines of every stripe.  Well-illustrated with photos and drawings, the assortment of sharpening “aids” in which to sink your money will make your head spin faster than a high-speed grinder.   I don’t recall Mr. Hock making a strong statement about any of these, so I will.  Put your money into a high quality set of stones, learn to grind your tools (and that doesn’t need to cost a fortune either) and save the rest of your cash to buy high-quality steel (like Hock irons, which are worth every penny you’ll spend)  or lumber.  All the rest of the doo-dads will probably end up gathering dust on your shelves.

The book runs 221 pages.  At least half of it is devoted to subjects other than sharpening.  Some of the “other” material – the discussion of steel, for instance – is very useful.  Some of the rest of  it I found less important.  Mr. Hock does have a very nice writing style, and some of his conversions from English measurement to the metric system will make you laugh out loud.  It’s a very readable book.  Reading it won’t turn you into a proficient sharpener but he doesn’t claim that it will, either.  This book is worth a look; you’ll probably find it on the shelves of your local Border’s or Barnes and Noble.  Compare it to some of the other publications on the subject (Leonard Lee’s The Complete Guide to Sharpening and Thomas Lie-Nielsen’s Illustrated Guide to Sharpening are two) and base your purchasing decision on that comparison.

Is this book really the “ultimate” guide?  Not in my opinion, but you be the judge.  Look at it carefully and thoughtfully and make the comparisons described above.  Then decide if it meets your personal needs for a sharpening reference book.

Get It Into – or From – Your Library

And finally, a suggestion for those of you who still visit your local library: if you look at the book in a bookstore and find it worthwhile, consider recommending it to your local librarian.  I have found that the Woodworking section of most libraries is horribly out of date, and I don’t know many librarians who are also woodworkers.  I’ve had great success making recommendations to my local library.  In fact, I can’t recall a recommendation for an acquisition ever being turned down.  Getting a recommendation from a patron can only improve the collection and make the librarian’s job that much easier.  If there isn’t already a nice selection of books on tool sharpening, this book would help to fill that void.

_______

Jeff Zens owns and operates Custom Built Furniture in Salem, Oregon. He is a frequent woodworking instructor and writer.

Categories: Sharpening, Woodworking | Tags: , , , | Leave a comment

Create a website or blog at WordPress.com

%d bloggers like this: