That’s a Funny Looking Chisel – Viewer Question
This question comes from Adam B. He asks:
Marc, I am watching your Entertainment Center Video (Pt 1) and noticed something odd with your large chisel. How did you flatten the back of it? It looks like there are three channels cut into it.
The chisels I use on the show (most times) are Fujihiro Japanese chisels. In general, Japanese chisels are made with harder steel than their Western cousins, which means it can take a lot longer to flatten their backs. And a flat back is an absolutely critical component to any chisel you actually intend to use! So to speed up the flattening process, a good amount of steel is removed from the back of the chisel. And as you can see in the picture, wider chisels can have multiple hollows. So now the actual amount of steel that needs to be removed in the flattening process is significantly reduced. Which means you are going to spend less time at the sharpening stone, and more time at the workbench.
This is the same concept behind creating a hollow bevel. Many folks prefer hollow bevels because they can be easier to sharpen, not just because of speed, but because its easier to balance with two points of contact. FYI, some may disagree with me on this but this is just my opinion from my experience. So the hollows are a little unusual-looking, but they do serve a purpose.
I borrowed the image to the right from a great article on FineWoodworking.com called “Speedy Freehand Sharpening” by Hendrik Varjhu.
Wood Talk Online #61
Questions or Comments?You can get a hold of us by either dropping us an email at woodtalkonline@gmail.com or you can pick up the phone and leave us a message on our voice mail at 623-242-2450.
What’s on the Workbench?
Marc – Just finished the Wall-Hanging Tool Chest for the Guild.
Matt – installed his bandsaw riser block…wow that’s tall!
News:
Norm is retiring!! Woodworking Magazine interview with Russ Morash, producer of the New Yankee Workshop.
International Dress Like Norm Day
In honor of Norm Abram, the folks at Woodworking Magazine and Popular Woodworking are asking all Norm fans to dress like the man, take a photo of yourself in costume and send it to me by midnight Monday, Nov. 2, at chris.schwarz@fwmedia.com. The person who sends in the best photo (as determined by our staff), will win a great prize.
Magazine Roundup:
Matt’s Pick: A Woodworker’s Journal article on green finishing by Micael Dresdner.
Marc’s Picks: Fine Woodworking’s “How to Design Furniture” book/magazine thingie and The “Build or Buy” article in the latest issue of Popular Woodworking.
Around the Web:
A couple cool iPhone Apps to try out- ID Wood and Boardfeet
Official website for Splinter “the car”- check out the veneer loom and more
Skateboards from fallen limbs and axes
Holiday Project Templates at Eagle America – Get ‘em while they’re hot!
PBS’s The Router Workshop Video Series ($4.00 for each month)
You will receive one episode per week of the Router Workshop. There are 183 episodes in this video library.
An Interesting Scenario to ponder:
17yr old kid wants to be a woodworker. Already has some shop experience and is showing great potential. Does he aim for a woodworking school or business school?
Listen to the show to hear advice from your fellow woodworkers, as well as the staff of Popular Woodworking.
Magazine Website Roundup (Pt. 2):
WOOD-
User-generated videos
How to Videos from the Wood Magazine Editors
Free tool demos
Over 100 Pay-per Download titles
Forums
Free Weekly Newsletter (no sales pitches)
More than 1000 woodworking plans for sale in the Wood Store
A comprehensive index of every article that has appeared in WOOD magazine
Woodworker’s Journal Offerings (Rob Johnstone – Editor in Chief, and don’t you forget it!)
Homepage
eZine (an online woodworking magazine emailed every two weeks)
There’s also two other sites of interest: WomeninWoodworking and FreePlans.com.
In addition to these websites, they also offer a fully digital version of the print magazine with supplemental digital content.
Of course there’s also an online store selling back issues, downloadable digital plans, books, CDs.
And they also have a blog page with Chris Marshall as it’s main blogger. But all of the staff at one point or another use from time to time.
Sweet Deals:
FREE Super Saver Shipping on ANY SIZE ORDER at Eagle America! Use promo code WOODTALK61 at checkout and select Free Shipping as your shipping method. (Offer valid for two weeks only, now thru 11/9/2009).
20% off Sorby turning tools and free shipping on Jet Lathes now through Nov 1st at Woodcraft.com
It Came from the Forum:
Woodworking in the Cold
Voicemail:
Roberto has a great question concerning planer/jointer blades: to sharpen or to buy?
Tom’s Tip (TomsWorkbench.com): BBQ’s make great mobile carts?!?!
Village Carpenter’s Tip: (Village Carpenter): Dental tools, for more than just torture!
A2 vs O1 Tool Steel – Viewer Question
This week’s question comes from Brian. He writes:
My question relates to tool steel. I am about to purchase a Veritas shoulder plane and for the first time am faced with the choice between A2 and O1 steel. I understand that A2 is the harder steel, which has the benefit of holding an edge longer and the detriment of being more difficult to sharpen. I understand that O1 steel is softer, allowing for easier sharpening to a keener edge, but one that will dull more quickly. Can you please confirm, to the degree you are able, that I am correct in my understanding here.
Secondly, can you let me know which steel you would choose and why? I am leaning toward the softer steel (O1 by my understanding) because I understand it is easier to sharpen to a keen edge. I am not going to put a lot of miles on this plane, so more frequent sharpening will not be a big burden to me. Thank you for your input. I continue to enjoy the site and The Guild.
Hey Brian. You are absolutely correct in your understanding of the difference between A2 and O1 steels. In general, O1 holds a slightly keener edge and is easier to sharpen. But it also dulls faster and require more frequent sharpening. A2 steel takes a little more effort to sharpen, but you are rewarded with a more durable edge that lasts longer.
As a person who uses a lot of exotic hardwoods and doesn’t enjoy sharpening any more than I have to, I prefer A2. When I am sharpening, it usually turns into an all day affair. So whether I’m using A2 or O1, I’m still getting messy and still spending hours getting my tools all prepped and ready to go. The A2 just ensures that I won’t be doing that as frequently. What you choose really does come down to personal preference.
Now I am by no means an expert in tool steel, so I thought we would go to someone who is for a more thorough answer. Here’s a reply from Ron Hock of Hock Tools:
“For our “high carbon” steel blades, HOCK TOOLS uses AISI (American Iron and Steel Institute) O1, a simple high carbon tool steel with very little added to the iron/steel alloy other than 1.1% manganese. That pinch of Mn allows the steel to harden with an oil quench (the “O” in O1 stands for Oil.) Oil removes heat more slowly than water, reducing the thermal shock that occurs when orange-hot steel is plunged into water. Reducing that thermal shock minimizes the risk of cracking or distortion in the hardened piece. With an alloy as simple as O1, containing so few alloying elements, the hardened grain structure is as fine as possible which allows honing to the sharpest possible edge.”
“AISI A2 differs from O1 with the addition of 5% chromium and 1.1% molybdenum, allowing it to quench in still air (“A” for Air.) While “stainless” amounts of chromium (12% or more) make tool steel “gummy” and hard to sharpen, the modest amount of chromium in A2 improves its toughness and abrasion resistance, but imparts only a slight measure of corrosion resistance (like high carbon steel, it will rust and appropriate preventative care must be taken.) But there is a trade off. During heat treatment the chromium addition combines with some of the carbon in the alloy to form chromium carbides – tough, hard particles dispersed through the steel. These carbides are the primary contributors to A2’s celebrated edge retention. However, during heat treatment, the chromium carbides can grow quite large – large enough to affect your ability to hone the edge as close to zero-radius as you may want. And these carbides are held in place with less strength than the rest of the steel matrix which can allow them to pop out under the stress of honing or cutting leaving a small gap in the edge.”
“A2 is one of the steels that respond well to cryogenic treatment. This extreme cold treatment (-320°F) essentially finishes the original quench, increasing the steel’s toughness without any decrease in hardness. You get increased wear resistance without any increase in brittleness so a cryogenically treated blade will hold its edge longer. You can keep working instead of sharpening. A2 is a great steel that offers a real improvement in edge retention. O1, on the other hand, is still preferred by many for its relative ease of sharpening and its ability to get sharper.”
Demo Night- Sharpening Options
Download High Resolution
This is a long clip from our new website feature, Demo Night. The topic was sharpening options. This live, interactive demo took place on our Wood Whisperer Live page. Everyone seemed to enjoy the new format and it looks like we will make this a regular feature. Check our Woodworker’s Calendar for upcoming demos. Obviously the audio and video are not up to the normal show quality, but this is the best we can do. Enjoy!
Check it Out!
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