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 Joel's Blog at Tools for Working Wood

How To Grind Part 2 - The Technology of Grinding -, Grinders, and Grinding Wheels  

01/11/2017



Part 1 is here.
These days when shopping for a grinder you have a huge number of choices. From $50 dry grinders from Asia to very expensive slow speed wet grinders with lots of attachments and everything in between. When I was studying woodworking (a long time ago) my teacher, who knew a lot about lots of stuff was scared of grinding. I think this is a common fear. We had a high speed grinder, with who knows what kind of wheel, no wheel dresser, and the fear of burning (overheating) the chisel was real. Burning was way to easy to do and the cure was grinding past the burn - which exposed you to the same issue only with a shorter chisel.

So many people are so scared of burning that they do all their rough work on very coarse diamond stones. This isn't totally off base either. In Japan having a grinding wheel on a jobsite was uncommon and working coarse grits on a stone was very common. In England (and the US I think) up until the invention of the small electric motor in the 1900's most people did not have ready access to a grinder. This especially applied to carpenters and joiners who worked on site. Saturday was the big day for hardware stores when craftsman took their tools to be ground if needed. Hand cranked grinders existed going back centuries but you need an established shop to work in and grinding wheel technology was natural stones which cut slowly - so it made sense to pay someone else to do it.

The revelation for me was when Barry Iles of Ashley Iles visited my shop. He needed to grind something, found my grinder, took all the guards, jigs, and thingies off it. Turned the grinder on, dressed the wheel, then touched the chisel he needed to grind on the wheel and was done 5 seconds later. I said "hey - can you teach me that" And he did, turning my entire fear of grinder away. It's not hard to learn. Actually it's pretty easy to learn.

Grinders
There are many factors involved in selecting a grinder.
Cost - that's pretty obvious. You can buy something that spins a grinding wheel for fifty bucks and it can work. As you work your way up the cost chain you get better materials, better motors, larger wheels, better bearings and more solid rests. Not to mention better customer service.

Wet or Dry
Professional grinders try to grind wet. This solves the cooling problem and you can grind fast. Until recently wet grinders were big complicated machines that were not designed for a home shop. In the past generation Tormak, a Swedish company, introduced a 10" grinder with a water bath for the wheel. Also available from Tormak are some of the best grinding jigs in the industry. It isn't an inexpensive piece of kit but the Tormak is very well made. My issue with the Tormak and all consumer wet grinders is that they are way too slow. The reason professionals grind on big wheels with a water spray is so that they can grind really really fast. The Tormak has a water bath (good) but it also turns really slowly and grinds really slowly (bad). As you get better at grinding the jigs are less and less useful.

Belt, Flat Grinder, or Wheel
Up until recently professional grinders all used large (4') grinding wheels but increasingly belt sanders of various sizes are also popular. A belt will run cooler, and you have a very large selection of grits. We have knife grinding equipment here and can easily hollow grind on a belt. However most less expensive equipment doesn't have that option and since one requirement of mine is being able to grind hollow, a belt sander isn't really a great choice for general woodworking tool sharpening. I have the same issue with flat grinding systems that use abrasive disks. In general they work slowly, I like a hollow grind, and I don't like having to replace disks. One point that should be mentioned. With some of the flat grinding system that use abrasive disks, and belt sanders (but to a lesser extent) you can not only rough grind but also polish. We power sharpen some carving tools on a Koch machine with uses paper wheels. Flat grinders can also polish but in general with a hollow grind I think hand honing is easier, less fussy, and faster.




How big a wheel
We stock two sizes of grinder: 6" and 8". 7" grinders had a certain vogue but currently there are fewer options for wheel selection. For normal woodworking a 6" grinder is all you need. You get a nice hollow grind, and the grinders aren't huge. Lots of turners however like an 8" grinder because the hollow is less and for some turning geometries a deep hollow is a disadvantage. An 8" grinder weight a lot more than the 6" which is great if you don't have to move it. My suggestion would be that unless you turn go with the 6".

How fast
The surface speed of a grinder is what dictates how fast we grind and at what speed. Many people recommend slow speed grinders - a 6" grinder running at 1800 RPM as a great way to avoid burning the steel (and it is). A 6" 3600 RPM runs twice as fast and grinds twice as fast, and by the end of this series you will be able to grind on it with no real risk of burning. We stock 8" 1800 RPM grinders which a surface speed between the 6" 1800 and 3600 machines. While faster (3600) grinders exist I don't recommend them, they grind very fast which can be an issue with heat, but also lots of the better 8" wheels aren't really designed for that speed.

Variable Speed
A couple of vendors offer variable speed grinders for sale. In general the top speed is slower than 3600 so what you end up with is a slow speed grinder that can go slower. In addition variable speed electronics are just not as reliable as a fixed speed. And why would you want to grind slower once you learn to grind faster. So I cannot recommend them.


Guards
With modern wheels there really isn't much of a risk of a wheel exploding. But an exposed wheel is always a hazard. A spinning wheel can grab a loose thread or hair, and rip off your arm or head. A trip and fall can have you grab out to a spinning wheel or have a tool ripped out of your hand with disastrous results. Baldor grinders, which we stock use heavy cast iron guards. That might be overkill but no matter what grinder you use make sure it has guards.

Eyeshields are also important to prevent flying debris. However even with shields always wear eye protection. Hopefully you will never need it. Over the years I have - more than once.

Dust collection
Grinders spit burnt steel and abrasive dust behind them. Some grinders (like the Baldor) have proper dust ports built it. Unless you have a dust collection system only for metal DO NOT connect your grinder to the dust collector. Metal sparks from burning steel and wood dust on a container are EXPLOSIVE.
My grinder is just far enough away from a wall so that it doesn't make to much of a mess.

Rests
We want a rock solid rest that won't move or flex during grinding. Some people clamp the tool in a jib and move the jig on a specially designed rest. If you plan to do the latter I suppose no rest is needed because you are going to replace it. Most rests that come with grinders are either cast iron or aluminum or bent sheet metal. Sheet metal sucks - it just bends under pressure. Cast aluminum is fine although it does get scratched from the abrasive dust. The grinders we stock have rock solid cast iron rests. These are by far my favorite. Solid, heavy, and no flex whatsoever. I think no matter what grinder you get if the rests aren't solid either buy an aftermarket rest or make something solid. It doesn't have to be complicated. I adjust my rest by getting it into the approximate correct position and tightening the clamps and then tapping it to final position. The method looks cludgy but works well.

Unlike a printed magazine which has page limits on a blog you can go on and on and on. Which it seems I have done here. On one side this is far more information that anyone actually needs, but I am trying to cover all the questions that I regularly get. As I have gone on at such length I think I will put "Grinding Wheel Chemistry and Nominclature" in part 3.
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How To Grind - Part 1 - When To Grind  

01/04/2017


Happy New Year! I thought I would start off the new year with some practical woodworking information. I have always thought that a grinder is one of the most important tools in the shop -- and it's also one of the least understood. While I do teach an occasional class on grinding at our shop (and will do so again in the future), most people don't live nearby, so written instruction seems in order. The last time I wrote on this subject, in the June 2008 issue of FWW, the response was overwhelming. But I have learned stuff since then, and technology has evolved.

This series on grinding will be in four parts:

1 Introduction + reasons for grinding
2 Grinding wheel and grinder technology
3 The angle to grind at, wheel dressing, and how to grind to maintain the existing bevel
4 Grinding to repair an edge


Parts three and four are hands-on; the rest is theory and background information.

There are three reasons to grind.

1 - To Maintain a Hollow Grind. Grinding an edge tool against a curved wheel will always result is some sort of curvature on the bevel. The larger the wheel, the less the curvature. We call this "hollow grinding" (see picture). Producing a hollow grind enables easier and faster honing. When you think about it a bit, the only part of the chisel that does any work is the cutting edge at the very tip. The rest of the chisel is just support for the edge. So the steel in the middle of the primary bevel is basically waste. With a hollow grind when you go off to hone the tool after grinding, you get a very stable platform of the tool solidly supported at the front and back edges of the bevel. You won't be wasting energy, stone wear, and time removing the middle of the bevel, you'll also get a simple way to make sure you are always honing at the edge. All the force is applied at the edge, and there is no tendency to wobble or rock the chisel. Hollow grinding GOOD!

2 - To Restore or Change the Geometry of the Primary Bevel Angle. Personally I am not fussy about bevel angles. The lower the angle of the primary bevel, the less force it will take to push the chisel into the wood. With less force comes more control. The trade-off is a thinner, weaker edge. A higher primary angle gives you a stronger edge, but more force is needed to punch it into the wood, and with that comes less control. The traditional angle of a bench chisel is 25° but a little more or less isn't a big deal. Paring chisels should really be lower by at least 5° and mortise chisel higher by the same amount. Every once in awhile I realize that my geometry on a particular chisel or plane blade is off enough to annoy me. This usually happens because after several years of honing I find the bevel angle getting steeper. These days, however, as I am hollow grinding to make honing easier and I don't have this problem at all. I'm also not personally adding new chisels to my toolbox - but certainly someone building a shop will always have "new to them" tools that need a geometry change.

3 - The Unfortunate Reason: To Restore a Damaged Edge. Probably the most frequent reason I end up grinding something. Chisels, plane irons and other display tools in our showroom get handled all the time and get dropped. Repairing a damaged edge is a little more involved than a just maintaining the hollow, but there really is no better way of repairing a damaged edge. Honing past damage, even with a coarse abrasive, just takes a lot of time and elbow grease.

The issue that many woodworkers are scared about when grinding is heat. The basic problem is that (with the exception of turning tools made from High Speed Steel (HSS)) if you heat up a hardened piece of steel past 400 degrees it will get start turning brown and blue and get softer -- and most importantly, it won't keep an edge anymore. HSS is called "High Speed Steel" because it can be heated up way past 400 degrees and yet stiff hold an edge. But in general, HSS won't hold a sharp enough edge for woodworking, and it's very hard to hone. The goal when grinding an edge is to achieve a ground edge without overheating or "burning" the edge. And a more important goal is to be able to consistently grind without burning because otherwise the crap shoot of what will happen is too scary.

There are three (or four) basic approaches to keeping cool when grinding. Use a very slow grinder. Use a grinding wheel that allows speedy steel removal without heat. Use some sort of coolant, such as water for wet grinding. Finally in parentheses: (grind really slowly and gingerly). The goal for me is to grind as fast as possible without any real danger so in Part Two we will talk about wheel and grinder selection, and how to keep a wheel grinding as cool as possible.

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Happy New Year, A Great Experience, Ideas for the New Year, & News   

12/28/2016


Over Christmas I went upstate to the 30th wedding anniversary party of a boyhood friend and his wife. We haven't seen much of each other lately, and it was great catching up with him, his wife, and groups of friends (some of whom I haven't seen in 20 years). The emotional connection with people and the recognition of the passage of time are part of what makes us human.

For my friends' wedding I promised to make them a blanket chest for the foot of their bed. The plans were from an article in a Reader's Digest book written by my woodworking teacher. It wasn't a huge project by any standards. It took me two years!

"Did you see your chest?" my friend asked.

"No," I said, thinking it was in another room.

"There it is," he said, and pointed to it. And there it was. In the living room, not a bedroom. It was, as you might expect, "part of the furniture." Covered with stuff, and inside, they told me, filled with things they don't use much. The cherry has aged well, and while I have build many far more complicated pieces since, this was one of the earliest things I made. I was really touched seeing the piece. One of the great things for an amateur about building furniture is that you can give it away and people treasure it. Every day they get the reminder of a long-ago connection. Somewhere on the chest I signed and dated it and probably wrote that it was a wedding present. And I put the info under the finish so it will stay put.


Back to the present.

We are in discussions about what products should be add to the store in the coming year. How should we extend the Gramercy Tools and BT&C lines? We have some ideas ourselves, but I would sure welcome some ideas. What are some of the products you wished we made or wished we sold? Send me an email with your suggestions joel@toolsforworkingwood.com.

In order to make space for new stuff, we need to get rid of old stuff. You can see our sale items here. We are adding more and more as we clear out some of the old items. Currently there is a lot of clothing on heavy sale, but more and more tools are being added daily.

I also want to give you a heads up about pricing. We will be raising prices of most of the Gramercy Tools Saws on January 1 2017. We haven't raised pricing in a few years, and our rent has doubled, materials have gone up etc. If you order at the current pricing we will of course honor the price even if we are out of stock and have to ship you the saw later. We are spending this week going over each tool and figuring out out current costs. Rasp prices will stay the same. Brush prices might go up a little but not for awhile.

I wish all of you and your family and friends a happy and healthy New Year. May you all find that piece of scrap that is just the right size for your project, and cut on the waste side of the line.



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Nail  

12/21/2016


I have written previously about TATHS so I won't repeat myself except to say JOIN NOW, but I just got the current issue of their magazine and in it was a link to a free ebook about nailmaking. Called "A Capful o' Nails" it's actually not about nailmaking but about the evils of working in the nailmaking industry. The book, written in 1896 is a fictional memoir about growing up in a family of nailmaker's and how the father became an organizer. So it's not about the nuts and bolts of making nails. But it is a story about the grinding poverty that effected so many industrial workers, tool makers too, just about all the semi-skill trades. In this particular case nailmaking was outsourced to level upon level of middleman until the lower paid people on the ladder were the actual nailmakers who worked out of their homes.

What I don't understand is that the story takes place in the mid-19th century. At this time in the US nailmaking was mechanized and industrial. We stock Tremont nails, which, depending on the model are still make on machines from this era. I don't know how long hand nailmaking lasted in England but you know that if your job can easily be done by machine (or automation, or a robot) at a fraction of the cost of a living wage - it's gonna suck. And it did.
Here is the link to the book.

The picture above is from the 1811 edition of the London Cabinetmaker's Book of Prices. I own an original copy but you can download a PDF here. The book is basically pages and pages of different types of furniture with lots and lots of special cases and tables showing how much the craftsman would get paid for that particular work. It's not the only price book of its kind, all over the UK and US these types of books were pretty common. But this 1811 edition is the most comprehensive and was used, basically unchanged, for at least a half century. The prices were the result of negotiations between the shop master and the union but under the table, and in non-union shops, prices were routinely discounted. The particular chunk I copied (which BTW is printed in beautiful letterpress- all they had at the time - but it is so lovely) is of two versions of knife case both costing far north of a pound wholesale. A huge amount of money for at the time. This is fancy work for rich people.

If you are traveling this week and you are looking for something to distract you, both downloads might be of interest. This season is when we reflect back on the year and the good and the bad. And also our hopes for the future. Both of these book gave me a sense of the past of the woodworking craft. From "A Capful o' Nails" I learned about the struggle of hard working people to survive. From the "Book of Prices" I got a sense of the work involved to make the furniture I see in museums today.


From all of us at Tools for Working Wood we wish you and your family happy and healthy holidays. With peace and prosperity to all.
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The Gramercy Tools Saw Etch Story  

12/14/2016


At the of the summer of 2006 Timothy Corbett and I had finished up the first Gramercy Tools Saw - the Bowsaw and were embarking on our next project - a dovetail saw. Earlier today I was writing a blog entry on the development of that saw and Tim shared with me some of the original artwork for the saw etch of the dovetail saw. I put aside my original story for now so I can bring you this.

The Statue of Edwin Booth stands in the center of the park and in the background of the final etch


We figured out that there are roughly two ways to brand a saw. Stamp or engrave the brass back, which was the common thing up to the mid 19th century, or etch the blade with acid which was popular in the latter part of the 19th century. Both of us really loved the artwork of the old saw etches and Tim, who had experience in acid etchings loved the idea of doing a proper logo for Gramercy tools, appropriate for a saw blade. Originally the etch was for a line of panel saws made for us by a third party but when we sent the artwork to the maker he could not do the detail we needed and the project was dropped. We finally found a company that could actually do a real acid etch on a piece of steel. Deep enough to withstand wear and analog enough to allow the classic detail that we wanted in a professional saw etch design.

The first drawing to show the real elements of the final composition


Gramercy Tools got its name because at the time we were located on 20th street in Manhattan and every day I walked past Gramercy Park, the last private park in NYC dating back since 1831. It seemed appropriate to do something related to the park.

A later sketch - we can see a sketch of the holdfast in the corner - an alternate view that was rejected


We started with a narrative idea, a joiner on his way to work in one of the fancy townhouse next to the park. I don't remember if Tim and I had conversations about the content of the etch or if he just came up with the design. But I do know on one hot day in the late summer of 2006 I found myself walking back and forth in front of the 20th street gates of Gramercy Park. I also lent Tim a copy of my reprint 1897 Sears Catalog so he would have some reference material on clothing.

Then he disappeared for a week or so. I only made two important contributions to the project. Complaining to Tim about how long it took him to draw the logo. And I suggested that some holdfasts to keep the etch from sliding off the saw would be a good idea. You can see he wrote "holdfasts" on the sketch.

The background isn't drawn yet but we can see where we are going


Days went by but soon we had finished art. The original is very large and done by hand. We use the etch on a lot of tools and at exhibitions. Depending on the size of the saw the etch will have more or less detail.

N.B. If you wish to see some of Tim's other, non-tool artwork his work is currently in an exhibition at The Invisible Dog open until December 30th. Go see it - it's a great show.!!!

Tim did some test photos to see how the banner bunting would look when held by a holdfast

The final etch with all its details





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Hayward vs Hasluck, Ellis, & Jones  

12/07/2016


With the release last week of the third volume of Lost Art Press's reprints of the writings and drawing of Charles H. Hayward I got to thinking about the other greats of woodworking writing and who is better for what. Paul Hasluck, Bernard Jones, and George Ellis were all pioneers in woodworking writing, starting in the last third of the nineteenth century and continuing until the early twentieth, They all worked at one time or another for "Work Magazine" and today, over a century later, their work is some of the best guides to Victorian woodworking practice. Ellis, ( Modern Practical Joinery & Modern Practical Stairbuilding and Handrailing are still in print) wrote mostly for professionals or really beginners striving to do professional type work. Other out of print titles of his were for late 19th century professionals and titles such as "Modern Practical Carpentry" are just the thing if you want to build a railroad trestle or flying scaffolding out of wood. His book of examination projects for carpenters, is an advanced exam for Edwardian framers, but today we have greatly simplified the process of framing so the book is out of print and rare. (When we set up our book ripper again I will scan my copy and post it but it will be awhile). I think I can also safely suggest that in the 19th century all these writers were still feeling their way on how to write instructional material. On one end was the professional, who trained by apprenticeship, and on the other were schoolchildren who were doing very basic stuff. These writers were trying to give instruction for people who didn't have the benefit of an apprenticeship but still wanted to build stuff. You also should realize that if you wanted to be a cabinetmaker in 1890 you left school and apprenticed at age 14. As a teenager you might take some classes using Ellis or his contemporaries as a textbook. But all of these writers (Jones excepted) expected that you know how to use your tools, cut straight and sharpen. Ellis's books for the most part skip basic technique.

Paul Hasluck was primarily an editor, taking material from many authors and turning it into a coherent whole. Carpentry and Joinery is possibly the best book ever written on late Victorian architectural woodworking techniques, but it's certainly not a book for the raw beginner. The writing is crunchy by modern standards, and the drawings while truly superb - and you can learn tons - aren't step by step (except for window layout). A beginner can learn about layout and structure and I think Carpentry and Joinery is a mandatory read for anyone doing architectural restoration.

Of the three authors Bernard Jones is probably the most accessible and useful to modern beginning woodworkers. The four volume Practical Woodworker series we stock is awesome. Jones makes a decent attempt to teach beginner hand skills and the books have a tone of a classroom text - with lots of extras. I learned a lot.

All three of these authors worked for Cassell's publication at one time or another but it was a rival organization that nurtured Charles Hayward. Percival Marshall was the founder and editor of "The Model Engineer" an awesome publication for metalworkers and in 1901 he launched a sister publication "The Woodworker" specializing in woodworking.

Charles H. Hayward became the editor of The Woodworker at the start of World War two. His unique ability to write well, draw explanatory materials, plus a professional apprenticeship as a cabinetmaker gave him the unique ability to explain how to do stuff better than anyone before or since. Lost Art Press has reprinted three volumes so far of his articles, grouped by Tools, Technique and Joinery. You don't get the narrative buildup that you get in Jones, or the traditional complexity of structure that Ellis and Hasluck delve into but you do get amazing short articles on all sorts of subjects, that really teach you important stuff. As the books are made up of independent articles you can dip in an out as you feel. Jones is trying to build a training narrative but Hayward is far more succinct, has a modern writing style, and between text and drawings you will understand more than you could possibly imagine.

I cannot imagine anyone not wanting to read Hayward, it's that good. I recommend Hasluck and Ellis for learning how Victorian architecture and carvings were designed and put together. Finally Bernard Jones has been a favorite of my for years for his traditional education and his attention to the details of woodworking.


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The opinions expressed in this blog are those of the blog's author and guests and in no way reflect the views of Tools for Working Wood.
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Recent Blogs:
How To Grind Part 2 - The Technology of Grinding -, Grinders, and Grinding Wheels-01/11/2017
How To Grind - Part 1 - When To Grind-01/04/2017
Happy New Year, A Great Experience, Ideas for the New Year, & News -12/28/2016
Nail-12/21/2016
The Gramercy Tools Saw Etch Story-12/14/2016
Hayward vs Hasluck, Ellis, & Jones-12/07/2016
A Failure to Communicate-11/30/2016
Guest Blogger: Chris Pye - Get A Grip-11/23/2016
New For The Fall and Other News-11/16/2016
New Tools - Fall 2016-11/02/2016
Too Much of a Muchness-10/26/2016
Long Planes in the Modern Workshop-10/19/2016
CBN Wheels - The Next Generation of Grinding Technology-10/12/2016
English Patternmaker's Paring Chisels-10/05/2016
Wisner Tool-09/28/2016
Krenov Quality Plane Irons-09/14/2016
Gabba Gabba Hey!-08/17/2016
Summer News!-08/10/2016
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