

It’s thankfully a rare occurrence in my experience, but I am definitely not immune to ink clogs in my fountain pens. Ninety-nine times out of a hundred I am very careful about what ink is in what pen, and monitoring that pen to be sure the ink doesn’t get screwy or constipate the ink feed, or ink reservoir. Careful or not, bad things can happen and leave you with a tough mess to put right. I was telling myself just the other day how lucky I’d been with my pens, despite the occasional use of ‘dangerous’ inks.
What does ‘dangerous’ ink mean exactly? It means those inks which have undissolved pigment that went into the making of the ink along with the dyes, chemicals, surfactants and antibacterial additions. Viscosity can be a fine balance. I mentioned in a blog post a couple of weeks back that the wine inks especially contain solid particles that have the potential of clogging your pen. On buying ink I have been warned several times about the De Atramentis series of wine inks, and their potential for clogging a pen. Another risky ink—and the villain of my story—is Sailor’s Kiwaguro Carbon ink. (kiwaguro can be translated as ‘extremely black’) I have used this particular ink for a long time and never had a problem until this week.
The problem? The Kiwaguro ink contains carbon nanoparticles as well as surfactants. The nanoparticles can be a problem in themselves, but the surfactants suspend the particles in the ink and can affect a fountain pen’s ink feed, producing clogging. No question it’s a strong and beautiful black, but one that should be used with care.
I filled my Pilot Custom 823 with Sailor Kiwaguro ink about two weeks ago, used the pen throughout the next day, and then returned it to my pen rack that night. Normally I remember, but this time I didn’t and so left the pen untouched until two nights ago. When I picked up the pen to use, I could see that there was plenty of ink still in the reservoir, but I wasn’t getting a smooth or wet flow of ink common to the Pilot 823. When I put the pen under a bright light I could see what looked like black gunk adhering to the mouth of the ink feed. I could also see the same gunk stuck to the inside of the barrel.
Using tepid water I flushed the remaining ink out, repeating the action several times to dissolve the solid buildup. I filled the pen with tepid water one more time, then stood it up in a small half-filled glass of water, which I then put into my ultrasonic cleaner. I ran it through about five three minutes cycles, then flushed the water out of the pen once again. There was still a small amount of the gunk visible in the reservoir and near the ink feed, so I again filled the pen with tepid water and left it to stand overnight. That did the trick. When I returned the next day, the pen looked as clean as a whistle.
I refilled the Pilot with Pelikan black ink and now it’s writing like a dream.
