Thread: Angle for sharpening Chisels

Hi Camo,

The book to go to for any and all questions like this is Woodworking in theory and practice by John A Walton. It is the Book that was used for cabinet making apprentices when I did my time at RMIT and for a long time before that. I go back to it all the time and any thing I need to remember I write down and slip in behind the front cover

First printed in 1947 , the chisels I can see in it ATM are even Titans by the look of it. I just bought a copy of eBay the other day for Apprentice no 7 so if he drives me nuts asking to many questions I can tell him where to look. Thats got nothing to do with answering questions here. where it's more of a pleasure.

Page 34 of the metric addition has a grinding bevel and a sharpening bevel for paring and for mortising

Paring , grinding bevel 20 deg sharpening bevel 25 deg

Mortising , Grinding bevel 25 deg sharpening bevel 30 to 35 deg

cheers Rob

not to hijack but a story about Walton and book The Traditional Tools Group (Inc.) -- Submitted Article

camoz it is also in the local library Item Display - Woodwork in theory and practice

2nd hand copy in Newcastle $14 http://www.booksandcollectibles.com...._id=383756015&

Thanks guys for your assistance.

I called today to see if I could purchase the book, but it looks like someone else must have beat me to It.

It sounds like a good book to have, so I will keep my eye out on the Internet for it, but $14 sounded like a really good price.

Chisels are now nice and sharp, and no hair on my arms, next step is to make a box for them.

Cheers,

Camo

For used, try abeBooks.com. They claim to have 6,000,000 titles in stock.

For sharpening, I do what's needed for the job that I expect the tool to do.
Bone cleavers and knot-busting chisels = 40 degrees.
My best Porsche kitchen knives & wood carving gouges = 20 degrees.
Wood carving knives, both straight and crooked= 12 degrees.
No mini, micro or nano bevels needed.

Wood working "paring" chisels at 20 degrees sounds right to me, like carving gouges.
The wood carving tools need to be "carving sharp" which lasts maybe 30 minutes at most. Tune-up rarely needs anything as coarse as a 4K waterstone. The chrome green honing compound _may_ have aluminum oxide in it as well. Anyway, approximately 50,000 grit.

Angle I use generally for box making and fine furniture 25 with a 30 degree secondary bevel.

Softer timber I use a 20 with 25 degree bevel for Aussie hardwoods 33 degrees seems to last the longest.

Word of warning, as I've found this one out the hard way, as your tormek stone wears (gets smaller) the setup gauge you use will read 25 degrees but in actual fact it is a much steeper angle than that because the diameter of the stone has shrunk giving you an inaccurate reading. Just a thought.

Cheers

Steve

Hi all,


Found another copy for sale, just checking with the seller to make sure it is the right book. The place I am going to get it from is........actually I don't think I will say.

Originally Posted by fineboxes

Angle I use generally for box making and fine furniture 25 with a 30 degree secondary bevel.

Softer timber I use a 20 with 25 degree bevel for Aussie hardwoods 33 degrees seems to last the longest.

Word of warning, as I've found this one out the hard way, as your tormek stone wears (gets smaller) the setup gauge you use will read 25 degrees but in actual fact it is a much steeper angle than that because the diameter of the stone has shrunk giving you an inaccurate reading. Just a thought.

Cheers

Steve

Steve,

I think they may have fixed this problem with my version. The angle gauge that comes with mine has an adjustment to change when the stone size changes size, and a gauge on the machine to show the wheel size. Searching the net they seem to be available as a spare part for example:

Tormek Pro AngleMaster Grinding Angle Gauge. #WM-200

image.jpg

Cheers,

Camo

On the Tormek I think a lot of people just hollow grind the bevel at 30 degrees all the way to the edge and then hone at the same angle. That leaves you with a nice little polished cutting edge and a matching little polished edge at the top.

I often wish I had a tormek or similar while fighting my bench grinder that is always itching to overheat something.

Hi Camo

You do not need to go reading books to prepare a chisel.

All blades - plane and chisels, etc - require equal treatment on both sides of the bevel. This means that you prepare the first 1/2" - 1" of the back of the blade to the same level as the bevel face. In my case I end with a 13K waterstone.

The back of the chisel blade benefits from being flat, or coplanar at least. This enables the chisel to be guided by a reference surface or fence. Note, as above, that only the first 1/2" - 1" behind the bevel needs be taken to a polished level.

Only once you have done this you are ready to grind the primary bevel.

Since you are using a Tormek, as I do, I will describe my preference.

I do not like secondary bevels on chisels (eg a secondary 30 degree bevel on a 25 degree primary bevel) since then the bevel is no longer coplanar and cannot be guided on the bevel face (as when paring BD). I want a coplanar bevel face, so I freehand it on a hollow grind using both edges of the hollow as a guide. In other words, the angle of the primary bevel is the same as the angle of the microbevel.

The angle of the primary bevel depends on the hardness of the wood you plan to use or the softness of the steel in the chisel. The harder the wood and the softer the steel, the higher the bevel angle required. That some of your edges were honed at 38 degrees may suggest that the steel was soft or it may just have crept there over time. In any event, 38 degrees is too high for general use. I might go this high for a mortice chisel, but even morticing in Jarrah I tend to stop at 35 degrees.

25 degrees is good for general work, 30 degrees when you are chopping, and 35 degrees when you are morticing. 20 degrees may be good for light paring, but edges do not last longer than a few cuts.

Choose something like 25 degrees to start, work with this a while, and increase the angle if you need to do so.

Regards from Perth

Derek

You may like a copy as well Derek, there is a lot more than just chisels. You never know what you are going to learn next.

they turn up on eBay all the time.

Here is the index for those into a good read.

Derek's post is distilled from hindsight. While I'd disagree on fine points with respect to wood carving tools = buy into what he says. It ain't magic and he knows that.
Pick any sharpening angle. Hold that angle through out the entire process. That's the key point, if there ever is one. To see a wire edge big enough to pick your teeth with is wrong. Just plain wrong.

Thanks RV

Regards from Perth

Derek

Originally Posted by derekcohen

That some of your edges were honed at 38 degrees may suggest that the steel was soft or it may just have crept there over time.

Derek,

Thanks so much for taking the time to go into such detail for me. I think you might be right about the possibility it may have just crept up. Just based on the time to square the edge on the grind stone I think the steel is reasonably hard.

I have had a bit of a play with it, and I think I will go back and change the angle a bit.

I was looking at the book more as a bit of a resource for other areas (the Tormek resources are plenty for the sharpening side of things), the main reason for my initial question was I thought I might be missing something (a trade secret perhaps) as to why this larger chisel had such a different angle.

Thanks auscab for listing the index, it has confirmed for me it is a book worth having.

Cheers,

Camo

No Worries Camo,

The Pictures of the index were taken from an older edition that I use at work, there is more to the later editions.
I just took pictures of the later one and will put it up as well.

Rob

Quite a few more pictures to show this book, the previous index is from a second or 3rd edition, this set of pictures is from a 1979 edition . The one with the Green cover with tools, I have seen a Yellow cover with tools and a plain Yellow cover as well.

I have a Keen interest in this book

It's interesting that to make way for more information in the Fourth edition they deleted some from earlier editions.

Rob