Fast forward to September 12, more than seven weeks after last using the Plumix, and more than three months after first inking it up. I picked up the pen and found that … the ink flowed perfectly and the pen wrote the minute I touched nib to paper.
The Plumix certainly looked neglected, though. Some drops of Cassis Black ink had crept onto the top of the nib, and had been hanging out there, inside the cap, over those two months.
In fact, the ink had actually crept along a little farther: it also had collected on the cap and section threads, above and below. And neither set of threads looked pretty.
Awesome. This promised some drama, finally. Could two months of this have damaged the nib or section threads?
Well, after swiping with a damp paper towel, I could see just how much damage the ink had wrought. Check out the photo below. (Spoiler alert: no damage.)
But look how much the cap threads were damaged by contact with the ink for months. (Oh, again, not at all.)
So, there we go: no damage. No issues. No permanent gunk. No staining. No pitting or corroding of the nib. No crumbling feed. No destroyed or melted threads. No scratched-up plastic. And not even a moment’s hesitation in the ink flow. All after being left unused for almost two months, and inked up for more than three months. No drama at all.
So, I think our experiment has reached the end. I don’t see the point of extending this test. The question has been answered, and we can all see the answer with our own eyes: a modern iron gall ink, for fountain pens, from a trusted ink maker, can sit for more than three months in a pen with a stainless steel nib, without issue. (Gold nibs also are safe, as we already knew.)
Now, of course this doesn’t mean I’m saying, “Leave this ink in your pens, mostly unused, for three months.” No, heck no. I don’t think that’s a good idea — with any ink. I torture-tested this pen to show that this category of iron gall inks is perfectly safe when used normally, with no special precautions. If it passes the three-month, extreme neglect, test, we don’t have to worry keeping it inked up for a month or so between cleanings.
Also note that I’m only talking about (1) an iron gall ink expressly for fountain pens, and (2) from a trusted ink maker.
I define a trusted ink maker as a company that tests its inks to make sure they are safe in fountain pens. Based on my years of experience using iron gall inks, I am confident in iron gall inks from KWZ, Platinum, Pelikan and Rohrer & Klingner. Add Montblanc, Lamy, which have in the past sold iron gall fountain pen inks which in my experience are also excellent and trustworthy.
Finally, these results don’t apply to iron gall inks that are “document inks,” designed for archival document permanence. Iron gall document inks are higher maintenance, and I recommend more caution if using those in fountain pens. This list includes one KWZ ink (Iron Gall Blue Black), and the Registrar’s inks made by various companies.
But that leaves us with a wide world of super safe iron gall inks like Platinum Cassis — the non-archival iron galls from the brands listed above.
So let’s celebrate. Good iron gall inks for fountain pens can be used in any fountain pens, even those with stainless steel nibs, without worry or special precautions. We know this, because we have seen it with our own eyes.