When building a solid wood chest dovetails running the full length seem like a no-brainer to me. They are super strong, resist racking, mechanically advantageous, etc, etc, blah, blah, blah. Most importantly, they look awesome and are fun to build.
I usually cut tails first, I do this because I am better at compensating for an off angle cut in my tails when cutting pins than the other way around. Also, I like being able to cut two boards at the same time. I lay out the spacing using a set of dividers and then use a saddle marker to trace the layout of the tails across the top of the boards and down the front.
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| Stepping Off Tails With Dividers |
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| Waste Marked and Ready to Saw |
I have learned the hard way multiple times that if I don’t color in the waste with a pencil I will cut off the wrong part. Heck, I’ve done it even with the colored in area right there beside me. I usually notice it just as I pluck the waste away from the board. Anyways, I saw with both my left and right hands; I’ve found my mistakes are smaller regardless of which hand I’m sawing with as long as I have a good field of view on my work. Due to the tilt on the saw to cut the dovetails I’ve gone to ambihanderous sawing and it does work better for me. The left is a little slower and binds a little more often than the right but it still works out. Once started the angle of the cut does not change, if it turns out that I’ve missed the mark it is better to finish out an incorrect angle with a straight cut than to try and correct and have a curved cut that finishes in the right place.
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Once done with the sides of the cut with the backsaw I use a fret saw to cut across the baseline. This is where my techniques change based on the scale of the work. On a small box or a drawer I will cut right across the line or very close to it and then clean up with a chisel after. I have found that with larger case construction this doesn’t work as well for me. With thicker materials I seem more likely to have a sloped cut with the fret saw which requires more chisel work.
Due to the scale of the job I minimize the chisel work somewhat by switching to a trim router. I set the trim router to the depth of cut matching the baseline and within a few minutes I have cleaned up a full 22” of joinery. This works particularly well when cleaning up the tails as having two boards paired up to do at the same time is a real time saver and stability enhancer.
With the tails cleaned up I transfer the marks onto the pin board, making sure to mark what the waste is. Then, the process repeats itself until the pins are cleaned up and ready for fitting. I like to mark with a dull knife blade because it leaves an indent where I can set a saw or chisel.
Test fitting is a pretty short process, there are always a few cleanups to be done but if the lines are crisp and I clean right up to them it goes pretty well. On a large case like this I only test fit about 1/3 of the way on each joint. That is enough to find any problems and still allows the joint to come apart though it does take some persuading.
Before assembling the case I wanted to add in a few details on the sides which will be most visible. I decided to add on some supports across the cracks which were previously filled with epoxy. These are likely unnecessary thanks to the epoxy and other case components but they are fun to do. They go by the name of butterfly keys, bow ties, or dovetail keys; no matter what you call them their purpose is to help control cracking and keep boards together. I have found that keeping them to within ½ of the thickness of the boards they are set into is a good idea; otherwise they can do more harm than good.
I start by cutting out a variety of butterflies from thin plywood or cardboard and sliding them around until I like the layout. Once satisfied those cardboard pieces become the templates to trace out on some scrap wood wich will become our inlay. It is best to cut out the butterflies of the wood you will use and then use each butterfly to mark out its own recess. Each one will vary a little and best results come from a case by case approach.
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| Playing Around with the Layout |
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| It's Faint but the Knife Lines Outlining the Excavation are Barely Visible |
I use a knife to scribe around the butterflies and then remove most of the waste (staying away from the line about a 1/16th) with a trim router. Then a bit of chisel work to clean up the recesses and time to test the fit. Just like the joints tested above I only test a little bit of the fit and then remove it, bevel the underside edges and put some glue in the recess. The keys are installed with a mallet and left slightly proud; then routed / sanded flush with the board.
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| Butterflies with Their Mating Recesses |
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| Proud Butterflies |
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| All Four Boards Ready for Assembly |
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