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Converting a Cartridge Pen into an Eyedropper

Tools you will need:

  • Thumbs
  • Discernment
  • A small flash-light
  • Silicone Grease

Tools you may need:

  • O-ring
  • Lots of paper towels
  • A washing machine

Unlike most of the items in the Repair department, this set of directions is not aimed at returning a pen to a state of previous function, but at making it into something it has never been.  The eyedropper pen is the oldest style of fountain pen filling, and for those who feel limited by the amount of ink available in a cartridge or converter it offers much longer runs between fill-ups.  Since most cartridge pens have relatively complex feeds, the major drawbacks of the filling style are moderated… but not, I caution, entirely abolished.  Even with a deeply complex feed, dribbles can happen.

On the whole, the easiest conversion is to simply apply some silicone grease to the threads of the section.  However, before doing this, a little thought needs to be applied to the candidate pen.  The first step is to unscrew the section, and not remove whatever cartridge or converter you may have left in there.  In fact, if there isn’t one, find an empty and plug it in; you’ll want it in step four.

The second step is to have a good hard look at the section threads.  If the conversion is not to become complex, you hope to find fine threads with a deep cut.  This sort of thread is easily sealed with an application of grease, while coarse, shallow threads tend to leave channels through which ink will flow… into unwelcome places.  There are ways to address this problem if you’re very keen to transform your pen into an eyedropper, but I will leave that matter aside for the moment.

Next, have a good look at the barrel itself.  Some pens have little vent holes in their barrels, and that is not the sort of thing you want to discover by turning it into an ink escape port.  The quickest way to discover these vents, which are usually in either the tail or about half-way along the side, is to pop the open end in your mouth and try to blow gently.  If the pen is going to remain a candidate for conversion, all that should happen is a pressurization; the hiss of escaping air is nature’s way of telling you to leave this pen alone.  It’s not impossible to press on that this point, filling the vent with some kind of caulk, but that’s a less reversible process and one I don’t want to get involved with.  Your conscience may guide you in this.

Both made by Sheaffer, but only the one on the left should be an eyedropper; too much metal on the other.

Now, why did I want a cartridge in the section?  Look upon it.  Look inside the barrel (which is easier with a small light source).  Is there any exposed metal?  This is generally a stop sign for the whole enterprise.  There are some bits of metal which are meant to come in contact with ink, but with a cartridge in place, they will be concealed.  Metal which is not meant to touch ink, like the aluminum section-collar of a Waterman C/F or the brass liner of a Sheaffer Agio, will rapidly pit and degrade if left in contact.  The point of the exercise is not to dissolve the pen, so if you find this as an objection to the conversion, abandon it.

If your candidate pen has overcome these hurdles, then you need only apply a reasonable amount of silicone grease to the threads and pursue the directions for eyedropper filling.  All set to write for the next month!

There are those pens that snagged the hurdle at the second step, the ones with questionable threads; it is still possible for to render them into an eyedropper pen.  You will, however, have to track down an o-ring which can act as a gasket.  The ring must not interfere with the cap’s settling into its proper place, nor should it put a great deal of outward pressure on the barrel, since that can lead to cracking; very bad news when the barrel is awash in ink.  The ideal candidate for this treatment will have an an unthreaded portion of the section above the threads, and the threads will be higher than the face of the bit with no threads, and the best will have enough room for two o-rings.  Silicone grease will still need to be applied to ensure the seal, so don’t ignore it; some on the threads will still help reduce the amount of ink the ring has to resist, so don’t ignore them either.


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