Thanks for the answers, everyone
I've been cleaning and rinsing my pen each Sunday before switching to a different one. This works without problems, but one: I can't get the ESSRI out of the convertors. Even soaking in warm water doesn't help, so I tried the least aggressive version of Steradent. (That's the stuff used to clean dentures / false teeth.) I disassemble the convertor, and soak it in a cup of warm water that has a quarter tablet of Steradent in it. Within half an hour, the convertors are clean.
Obviously, I rinse them liberally with clear water.
Now, I only hope the insides of the pen don't have the same problems as the convertors....
Many thanks for keeping us up to date as things progress. Your attention to detail is admirable, and gives a sound basis for evaluation and comment.
I have no idea why the converters are not coming clean. (?) They'd be the last place the ink would dry-out, so I rather doubt that what's left after a clean-up would be anything iron based. I've not noticed such behaviour in converters or ink windows of piston fillers. If you take a very slender swab, then very gentley introduce it into the ink tank of the converter, will the residue wipe free?
Other than Steraclean, did you use any chemicals stronger than a very dilute acetic acid rinse in the clean-up? As mentioned by Member pharmacist, (ESSRI IR Post № 271), the acetic acid rinse should be done prior to using other clean-up chemistry.
__ Edit to add: When you take the pens out of rotation do you leave them disassembled? It is my personal practice cap them, but without the converter attached to the section.
Edited by Sandy1, 15 June 2014 - 23:06.