Tsunago: The Ultimate Geek Tool

The early roots of a dream.

One of my earliest memories of colored pencils is of the Empire Sunset Dual-Kolors with a different color on each end. Endlessly impressive when I was five years old, bicolor pencils are still at the height of pencil coolness for me. So much so, in fact, that my dream for the past several years has been to be able to make my own. Of course, I can easily buy bicolored pencils (and unlike those nostalgic Dual-Kolors, some contemporary bicolors contain useable pigment), and I do, but I have reasons for wanting to make my own pairings. For example, it would be handy to have a soft and a hard core of a single hue on either end of one stick. Or to simply build a set of water-soluble bicolor pencils, which do not exist commercially – I could carry twice as many colors in the same space.

6/22/19 The Tsunago

Imagine my thrill when I discovered the Tsunago, a Japanese device that joins two pencils together. Most of the marketing information I read about the product promoted it as a way to thriftily use up a pencil stub that is getting too short to hold comfortably by attaching another stub to its back end. But I instantly saw its greater potential: I could join the back ends of two colored pencils, and voila! A bicolor pencil!

After reading more about it, however, I learned that it only worked on standard graphite pencils, not colored, and it was apparently a finicky, high-maintenance bastard anyway. The concept was genius, but the execution less so – especially at a price of more than $30 for the gadget. Discouraged, I put the Tsunago on a back burner – but not the dream.

Fast-forward several months, when I had the opportunity to swap some pencils for a used Tsunago that had thoroughly disappointed its owner. For the price of a few pencils, my dream was rekindled!

Before beginning, I downloaded written instructions and viewed a few YouTube videos, one of which was made by the manufacturer. The instructions were explicit that the device is intended for hexagonal or round pencils 7 to 8mm in diameter (most standard pencils) and with cores of 3mm or less (eliminating most colored pencils). Furthermore, the ideal length for the joined pencils is 18cm or less (the length of a standard new pencil). This means that each pencil to be conjoined should be about 3½ inches long (the fabled “Steinbeck length”).

A few warnings in the instructions made me a bit leery, such as “You may form blisters on your fingers when opening holes in numerous pencils at once.” One video cautioned that the device should be avoided by people with arthritic hands or bad wrists. How bad could it be? Nonetheless, I proceeded with caution.

The concept of the tool is simple: On the tail end of one pencil, drill a hole (the “female” part, in hardware parlance). On the head end of a second pencil, shave off some of the outer wood while leaving a peg made up of the pencil’s graphite core and enough wood around it to support it (the “male” part). Apply a bit of wood glue into the hole, and insert the peg into the hole. Done. Simple, right?

Test 1: Two Blackwing pencils (with ferrules removed)

Before tackling the unadvised colored pencils, I decided to practice on two Blackwing pencils of the recommended barrel shape and size, core diameter and length. However, instead of adjoining one head to the other’s tail, I chose to join them tail to tail, making both ends useable (and frankly, much more practical than simply adding on a slightly longer tail). This meant that I had to first remove the ferrules on the two Blackwings. In addition, the adjoining edges must be flush, so I also had to carefully saw off the ratty end of one Blackwing where the ferrule had been attached. This took more work than I expected; snapping a pencil in half is much easier than cutting it carefully. In fact, after cutting, I had to file off the rough edges.

 

Raw end of Blackwing cut off.

Step 1

Step 1 in progress. I still have a ways to go... the end of the
blue pencil must reach the red line.

The multiple parts of the Tsunago are clearly labeled to guide the sequence. Step 1 is to drill out a hole, and with an actual drill, this step would be fast and easy. Instead, the tool at Step 1 is more like an awl. (It’s dark inside Step 1’s cavity, so I couldn’t photograph it.) You must rotate the pencil carefully (to keep it centered) while also pushing with firm but not excessive pressure (which could splinter the wood). The awl slowly augers away at the graphite and some of the wood. This step must continue until the end of the pencil reaches the red indicator line – about an inch of augering. In the written instructions and the videos I viewed, no one mentions how long this step takes. It took me a good 15 minutes, at least (and I started to understand the warnings about arthritis and bad wrists).

At the end of Step 1, I had a decent-looking hole in one Blackwing.

 

Step 1 hole completed.

For Step 2, I realized it would be easier to shave away the wood on the sharpened point end of the second Blackwing rather than the rough tail end that had been inside the ferrule. To ensure a flush end, the point must be shaved all the way down to the pencil’s collar (where the sharpened part meets the paint). A breeze compared to Step 1, this step took only a few minutes.

Step 2

Step 2: Blackwing peg formed

The tool in Step 3 refines the shaving that was completed in Step 2. Rough fragments of wood are filed away, producing a smooth peg.

 

Step 3: Peg is refined

Step 3

Per the instructions, I first tested the fit by inserting the white Blackwing Pearl’s protrusion into the blue Blackwing 73’s hole by using a firm twisting motion. The joint felt snug and secure, so I proceeded with the final step.

I applied a few drops of wood glue into the hole, using a toothpick to poke the glue down into the channel as much as possible. Then I Tsunago’d the two pencils together. After wiping away the excess glue, I could see that the join wasn’t as clean as I would have liked – the edges of both pencils probably weren’t perfectly flush – but I was happy with my first Frankenpencil attempt. I had a very practical, double-sided Blackwing – one side with the softest MMX core, and the other with a slightly harder Pearl core.

Wood glue conveniently found on the spouse
man's work bench.

Cavity filled with glue.

Not a perfect join, but not bad for a first try.

First completed Frankenpencil! It's the same length as an unsharpened Blackwing.

Encouraged, I decided to attempt the pairing I was most interested in: Two colored pencils. Within the limitations of barrel and core size, most of my colored pencils were eliminated, but two seemed possible. One was a Mitsubishi vermilion/Prussian blue editing pencil (I’ve been using it frequently lately for value studies), which has a core diameter of 3mm. The second was an orange Blick Studio colored pencil, which has a 4mm core – only a bit larger than the recommended maximum (I made a conscious choice to take the risk). Pairing the blue side of the Mitsubishi with the orange Blick would give me an interesting complementary unit for more bicolor studies.

 

Test 2: colored pencils

My first step was to hack off the blue end from the editing pencil. (Yes, I am aware of the deep irony of splitting apart an existing bicolor pencil to experimentally conjoin half to another pencil. But Dr. Frankenstein would not have let irony stop him, and it wasn’t about to stop me.) I wanted to retain as much useable blue core as possible, so I measured against the red indicator line in the Tsunago’s Step 1 chamber, cutting with a full inch of allowance on the vermilion side. I sanded the raw end to make it as flush as possible.

 

The rough hacked end had to be sanded smooth.

I measured the cut carefully so that I would have as
much useable blue core as possible.

Step 1 complete.

Compared to the Blackwing, drilling out the Mitsubishi was slightly easier and took less time, either because the pigment core is softer than graphite or because I had gained experience as a Tsunago driller (probably both). The hole looked clean and precise.

Step 2 with the orange Blick was a different matter. Inserting and twisting the point in the Step 2 sharpener, the point broke off inside almost immediately. After dislodging the broken core, I continued shaving off the wood, but I could see that the blades were cutting the core, too. It suddenly became very clear why a 3mm core is the maximum recommended. I kept shaving away, hoping that a thin veneer of wood would be retained around the core to build a workable peg.

 

The point of the Blick when I began Step 2.

The point broke off almost immediately inside
the Tsunago.

I kept going with Step 2, even though I had a bad feeling about it.

I tried inserting the resulting peg (orange core with fragments of wood around it) into the Mitsubishi’s hole, but after a couple of twists, the protrusion broke off inside. It was a clear, total failure. I fully understood now why it’s critical for the core to be 3mm or smaller – at least a millimeter of wood must support the peg’s core. 

Looking worse after the test insertion.

Total failure.

On the upside, the Mitsubishi’s hole was fine, so at least in theory, two colored pencils could be conjoined if both have cores of 3mm or less. The downside is that I don’t often use colored pencils with cores that small (the editing pencil is a rare exception). In retrospect, I might have been successful if I’d drilled the hole in the orange Blick pencil and made a peg on the Mitsubishi pencil. (Perhaps I’ll save that experiment for the next snowstorm.)

Before I put away the Tsunago, however, I had one more idea: A while back I reviewed the Viking Verso. This unique, innovative pencil has an HB grade graphite core on one end and a 4B grade on the other – a versatile graphite pair for drawing. At the time that I was using it, my Tsunago thoughts were reignited – and now that I owned a Tsunago, it was time to give that idea a try.

For my last Tsunago experiment, I paired a classic Blackwing with the softest core, which is about a 3B or 4B grade, and a Mitsubishi Hi-Uni with an 8B grade. While grades 9B and softer in the Hi-Uni line have extremely thick cores, the 8B’s core is exactly 3mm, so I knew it would qualify for the Tsunago treatment. The Blackwing has a standard writing core of about 2mm.

 

Test 3: graphite cores of different grades

The hardest part about this experiment was the initial prep step: It broke my heart to cut off the Hi-Uni’s gorgeous end cap (ahhh, the sacrifices I make for geeky science), which is one of the most beautiful I’ve ever seen. In fact, I was nearly in tears trying to saw it off, especially when I realized that it’s made of plastic, not varnished paint like the rest of the pencil, and the knife wasn’t going through at all. After making a shallow groove in the cap, I took some pliers to see if it would snap off at the groove, and that’s when the cap popped off. After that, it was easy to cut through the bare wood.

 

Alas, the gorgeous end cap had to go.

Hacked.

Drilling through the Hi-Uni for Step 1 went well, as did shaping the peg on the Blackwing. The Uni-Wing Frankenpencil lives! It’s going to be a useful drawing pencil, too.

Step 1 completed.

Step 2 completed.

Two successful Frankenpencils; one total failure.

Why Use a Tsunago?

If you’ve stayed with me through this long and perhaps tedious review, I owe you some final thoughts to help answer the question, Why would anyone use a Tsunago? If your intention is to save money and reduce pencil waste by using up more of a pencil stub, forget it. Just get yourself a simple, inexpensive pencil extender. If you use a specialized pairing of graphite pencils such as my Uni-Wing experiment, and you travel so light that carrying one stick instead of two is important, those might qualify as legitimate needs for a Tsunago. Be prepared to spend at least an hour putting together your pencil.

Frankly, though, I can think of only one reason to use a Tsunago: to earn absolute, undeniable credibility as a bona fide pencil geek.

Would Darth Maul use a Tsunago?