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.
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.”
Greg’s Steel Shop – Shop Tour
This Viewer Shop comes from Greg. Check it out!
My shop shares a 30’X50’X14’ steel building with a guest suite, laundry area, tractor, 4-wheeler, welder and all the other stuff you would expect to find inside a barn. The shop itself is concentrated in one corner of the barn but, with the exception of the guest suite, I’m free to spread out and take over the rest of the space if a project demands it.
Other than hiring crews to pour the slab, bolt the steel together and spray foam the whole thing, we built the barn ourselves which allowed me to get downright picky with the details. For instance, the electrical circuits in the barn are many and the shop area runs off a sub panel that is right next to where I hang my shop apron and ear protectors. The first thing I do to start my day is lift the apron off its hook and flip all the breakers on. The last thing I do is hang my apron up and flip the breakers off. That way I know the various chargers, the radio, air compressor, dust collector, all the large tools, even the shop lights themselves, (Lots of lights with provision for even more!) will not get up to no good and create a mini Chernobyl while no one is there.
In the front corner of the barn where my shop area is concentrated is a 7.5’X5’ storeroom. This gives me 24” deep shelves on one side and a little bit of bare wall for hanging fixtures and jigs on the other with a comfortable aisle between.
There’s a fixed bench with drawers and overhead cabinet backed up against the outer wall of the storeroom that provides quite a bit of storage as well as work surface. This bench, my rolling workbench, the table saw, and the router station were all built to have a finished surface height of 37” which makes handling large pieces pretty simple. My faithful tool cabinet, which is the oldest shop-built piece I have, conveniently hangs on the wall next to the fixed bench.
Like everyone, I drool over massive cabinet saws, but like most, don’t have the budget, so I turned my contractors saw into my version of a cabinet saw by building a base with some storage and plenty of extension tables. The whole thing is on 6 heavy locking casters but in practice I don’t move it. Placed as is, opposite the fixed bench, I can rip a 10’ board by starting with the far end resting on the fixed bench and placing a couple roller stands or my rolling workbench in between. The swing-up out-feed table is long enough to balance an 8’ cut without needing additional support though I can roll the router station into position to act as even more out-feed table if necessary.
I can also make as much as a 52” cut to the left of the blade by removing the handle on the jointer fence. Just in case I do move the saw, dust collection is arraigned so that I can hook up to either end of the cabinet. In practice a short length of 4” hose stays permanently attached between the left side and a dedicated port.
My primary work bench is a maple top I purchased and set on a shop built cabinet with locking castors. Usually the rolling bench stays right where it is in the photos, but if I need the space I turn it 90° and roll it between the table saw and fixed bench. When pushed up against the table saw, there’s plenty of room between the two benches to work comfortably.
The jointer might look a little tight, jammed in there between the wall and the table saw, but in practice it works just fine though it is on a roller base so it can be moved if I need to. For small pieces I use the router station right where it is. Larger work requires me to roll it out away from the wall a couple feet. That strange little room beside the router table, houses my air compressor and dust collector. I built this space around a Delta 1hp unit with garbage-can cyclone collector sitting beside it. The Delta was adequate but eventually I decided I needed a larger unit (To quote Tim Allen “More power! Arh arh arh!”) In order to fit everything in I had to take the new 2hp Grizzly apart and hang the motor/impeller assembly from the wall above the garbage can which now sits in the motor’s rightful place on the mobile base.
I have a number of baker’s racks on casters that I use as project carts. Just steps from the shop area I have a laundry tub with first aid and eyewash station and the bathroom, with large shower, can be accessed directly from the shop as well as from the guest suite. (We have slide bolts on all the doors to prevent accidental encounters!)
My shop isn’t perfect, I don’t expect any shop ever is, and there are a few self inflicted (Read bone-headed!) design flaws, but every time I open the doors in the morning I can’t stop grinning because I can hardly believe it’s really mine.
Sculpted End Table – Project of the Week
This week’s project should look familiar. I had a few requests for “beauty shots” of the final product. So, here you go! Enjoy.
Check it Out!
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