I have a 1964 Pilot Capless in superb condition, except for one thing--I cannot get ink to flow from the cartridge to the nib. I've thoroughly cleaned it, with good long soakings in an ultrasonic bath, interspersed with alcohol rinses... it seems that I can no longer get trace ink to leak from the nib assembly. The feed part underneath the nib is mostly clear now, as if it were new.

But I attach a full ink cartridge to the feed nipple, and there's just no go. I've even squeezed the cartridge a bit, but that doesn't seem to get any flow going. I do get very small blotches of ink residue appearing on tissue paper, but it is clearly from the previous ink. I'm not sure how the feed opening is supposed to look, but within the "tube" is a solid mass. I'm not sure if this is normal, but it looks like it is made of firm plastic, rather than dried ink.

I'm starting to wonder if this pen may have had a dose of India ink at some point in its life. Could that stuff solidify to the point of not breaking down by hot water or alcohol?

Any suggestions on another solvent to try? Thanks...

If you've tried ammonia, try kooh-i-noor. It'll take care of it if it is a clog, especially if you add some to your sonic cleaner. It'll clean india ink. Prolly the best place to get it is your local art store.

Thanks for your tip, Pete. I also heard back from Carmen Rivera, the undisputed historian of the Pilot Capless pen. She advised: