Chamfers are a mainstay of the Arts & Crafts style. Chamfers are often used to soften the ends of through tenons and are used extensively in contemporary pieces, and through out original Arts & Crafts casework including Stickley’s Harvey Ellis designed number 700 bookcase and Morris Chairs.
I cut my chamfers after milling is complete and my stock is prepared for finishing. This may seem out of order, but you don’t want to cut your chamfers first and then prepare the boards for finishing, because this sequence may put your chamfers out of symmetrical alignment.
If you haven’t cut chamfers before, or it’s been a while, it’s not a bad idea to cut a few extra pieces of stock for warm-up practice. I recommend you do this with the same material you’ll ultimately cut your final chamfers on because if you practice on poplar and then move to quarter-sawn oak, you’re going to experience a big difference in the amount of force necessary to use the block plane.
I begin by using a marking gauge to lay out the chamfers. In these images I am applying a 3/16” chamfers to boards that will be used in a picture frame. The boards are 3 ¼” W x 1” thick. I lay out lines on the faces, edges, and four sides of the end grain. I lay in deep strike lines for several reasons. This allows me to easily highlight them with a pencil, which aids in hitting my target when roughing out the chamfers on the disc sander. They also provide feedback when I’m fine-tuning my chamfers to ensure that they are symmetrical. The other thing I like about using the marking lines is they say, “I was hand-cut!”
I’m now ready to cut my chamfers, and I do this in two steps. In the first step, I use a disc-sander to rough out the basic shape of the chamfers. This serves three purposes. First, it establishes an exact 45 degrees angle to ensure sharp, symmetrical chamfers. Second, it creates a reference plane to register my block plane when completing the chamfers. Third, it removes the bulk of the material, which would take much longer if done by hand.
The first step is to use my combination square to set up the sanding jig at 45 degrees on my disc-sander table. I use a 20” 1.5 HP disc-sander with a 100 grit wheel. A delicate touch allows me to quickly rough out my chamfers.
If you’re inexperienced, this setup can quickly remove too much material and ruin your stock. If you lack finesse or experience, you can still precisely control how much material is removed by slowing the removal rate. Do this by hand-spinning the wheel. Without turning the sander on, spin the wheel a couple times by hand and then introduce the stock to the wheel. The stock removal rate will be much slower and you’ll be better able to control how much material is removed.
Stop removing the material just shy of the layout lines, leaving just enough material for three or four passes on each chamfer face with a block plane.
The hallmark of a great through tenon is ensuring the complex end-grain patterns of quarter-sawn white oak pop out when finished. I have found the best way to get this effect is to finish the chamfers by using a sharp block plane and making a slicing cut.
However, balancing even a small block plane on such a small surface can be challenging, particularly on the short edges. Here’s how I do it. I start by securing the stock in my workbench’s tail vise at a comfortable working height. Then, holding the plane in my dominant hand (I’m right-handed), I register the plane’s toe on the chamfer. I stabilize the back of the plane so that I can push through the cut.
Next, I wrap my other hand around the stock and assume a grip that allows me to register my index finger on the base of the block plane’s toe section. This hand allows me to augment the stabilizing force on the plane and maintain the proper balance on the reference surface as I push the plane across the chamfer.
Now push through the cut. I make three or four cuts using this technique. I know I’m done when the layout lines are barely visible or gone. To preview the edges, you can wipe on mineral spirits to simulate an oil finish. Do not slice-cut the ends of your stock at this time unless you’ve completed all length sensitive processing of the pieces.
That’s it! Your chamfers are now complete.
Three ways to check your chamfers:
Depending on the available visual references, the human eye can sense a line that is as little as 1/32” out of square. To ensure my chamfers will pass muster, I use several techniques to see if they’re as I intended.
- The simplest check is a visual inspection to confirm that the layout lines are connected. If so, it is very likely 45 degrees.
- Another way to check is to measure. In our case, both sides of the chamfer should be 3/16” from their reference face.
- But the surest way is to measure with the 45 degree portion of your combination square handle.
How Sharp is Sharp?
Much has been written about sharpening processes, techniques, and hardware. While an in-depth discussion of these topics is beyond the scope of this post, I do want to share a few thoughts on sharpening as it pertains to cutting chamfers.
Cutting chamfers is primarily cutting end-grain, and cutting end-grain is the standard I share with my students regarding how you know when something is sharp enough. Shaving the hair on the back of my hand, or seeing if I can dig an edge into my fingernail, or cutting paper are all impressive feats, but they are not functional. I’m not preparing to shave hair, trim fingernails or cut paper. I’m preparing tools to work with wood. Thus, if I’m working with quarter-sawn white oak, I know my chisels and plane irons are up to the task if I can cut quarter-sawn white oak end-grain, in a controlled fashion.
There are multiple processes, techniques, and hardware that can be employed to get a reasonably sharp edge, but I find the way to get extremely sharp edges is to go through my normal sharpening process, and then go through the additional step of honing with a very fine stone. I do this with a 30,000 grit Shapton water stone. A translucent Arkansas stone or diamond paste could also serve this purpose.