How Much Ink Will A Feed Hold By Itself?

July 11, 2015

The persistence of an apparently empty fountain pen can be an amazing thing. This is not a new thought around here; it's been mentioned fairly frequently, and I've certainly run into enough examples on my own. The other day I unscrewed a Platinum 3776 to see how much ink was left in the converter. Nothing but stains. I turned it nib up to see if any ink would run back into the converter; nothing. And yet I still got another four pages out of it, in a journal only slightly smaller than an A5 size, before it skipped and sputtered to a halt.

No mystery, of course. Like a sponge, a fountain pen feed can absorb quite a bit of ink. What I wonder, though, is if anyone has tried to measure the actual capacity of different feeds. Some desultory Googling failed to produce an immediate answer, so I thought I'd ask here.

It's just idle curiosity, so I'm not motivated to disassemble any pens that work perfectly well to do this sort of testing. I imagine that one method would be to remove a feed completely from the pen, immerse it for a minute or two in a measured amount of ink, remove it, and then measure the ink that was left. Does anyone know of any such studies, by this or other methods?

Incidentally, I can think of two opposite reactions to these pens that just keep on going and going and...

This is great! I can finish taking notes in this meeting without having to borrow somebody's chewed up ballpoint.
Darn it! I want to fill another pen, but I committed to writing with this one until it's dry.

July 11, 2015

I usually get a bit over a page (8" x 11") from most of my pens.

July 11, 2015

The P 51 goes forever it seems. The collector really holds a lot. Much more than many pens -especially modern pens. And an aerometric holds a good amount anyway. Can't speak to a vac.

July 11, 2015

How odd... Just this morning, I found a way to measure this. I filled a Platinum President converter with a syringe (filling only the clear part of the converter, so that there wouldn't be any spillover when I inserted the converter into the pen), and then inserted it into the pen. I then held the nib over the ink bottle, and turned the converter knob until a drop of ink came out of the nib. To my surprise, the clear area of the converter was now only about half full. I don't know how much the clear area holds, but you could easily find out using water in the syringe. If you have the tools, try it. Hope this helps.

July 11, 2015

It will depend on the pen, meaning that it depends on how fine the nib is, how fine the ink channels are, how fine the collector fins are. The finer the fins, the more there are, and the more ink it will retain. From testing pens with flow issues, I find that a balky pen will write a page to a page and a half of loops before the feed is emptied.

July 11, 2015

Hi,

I found it varies considerably, and is greatly dependent on the complexity and size of the collector.

On the lower end we have the rather abbreviated ~~feeds~~ collectors of screw-out assemblies, such as the Estie, Pelikan M-series, and the TWSBI 5nn series.

On the upper end, pens such as the Waterman Carene have a massive collector. It is such that several fill+flush cycles of the converter piston are required to fully flood that pen - the first draw of ink often returns nothing to the converter, which at first made me think the converter was not seated.

If one is profoundly curious to determine just how much ink a c/c pen will hold when the reservoir is empty, I suggest weighing the pen without the reservoir before and after filling: the difference in mass will translate to the amount of ink in the pen feed+collector: ~1 gram per milliliter.

One of my exercises in blonde optimism was to charge a Parker 61 with a capillary filler with PR DC Supershow Blue (very high dye-load) then just keep dipping the capillary filler into water to dilute the ink and keep it writing, albeit at lower Value as things progressed. About 70 A4s at 'reasonable/readable' appearance came from that pen+ink combo. Which lead me adopt the 61 as my travel pen - no need to carry an ink vial for short jaunts.

Bye,

S1

Borrowed photo of the Carene feed+collector:

Edited July 11, 2015 by Sandy1

July 11, 2015

How odd... Just this morning, I found a way to measure this. I filled a Platinum President converter with a syringe (filling only the clear part of the converter, so that there wouldn't be any spillover when I inserted the converter into the pen), and then inserted it into the pen. I then held the nib over the ink bottle, and turned the converter knob until a drop of ink came out of the nib. To my surprise, the clear area of the converter was now only about half full. I don't know how much the clear area holds, but you could easily find out using water in the syringe. If you have the tools, try it. Hope this helps.

That indeed might work. The next time I use a converter filler I may try it. Thank you.

Possible refinement. Fill an ink vial, the kind with a conical depression at the bottom, with a measured amount of ink, using a syringe with as fine gradations as possible. Fill the converter from that. Using your method, expel that single drop of ink back into the vial. Now remove the converter from the pen, and expel all the ink in it back into the vial. Remove the ink from the vial with the syringe, and see how much less is in it now. That must be the amount that is sitting in the feed.

Yes, the next time I fill a converter pen, I must be certain to try this.

Hi,

I found it varies considerably, and is greatly dependent on the complexity and size of the collector.

On the lower end we have the rather abbreviated feeds of screw-out assemblies, such as the Estie, Pelikan M-series, and the TWSBI 5nn series.

On the upper end, pens such as the Waterman Carene have a massive collector. It is such that several fill+flush cycles of the converter piston are required to fully flood that pen - the first draw of ink often returns nothing to the converter, which at first made me think the converter was not seated.

If one is profoundly curious to determine just how much ink a c/c pen will hold when the reservoir is empty, I suggest weighing the pen without the reservoir before and after filling: the difference in mass will translate to the amount of ink in the pen feed+collector: ~1 gram per milliliter.

One of my exercises in blonde optimism was to charge a Parker 61 with a capillary filler with PR DC Supershow Blue (very high dye-load) then just keep dipping the capillary filler into water to dilute the ink and keep it writing, albeit at lower Value as things progressed. About 70 A4s at 'reasonable/readable' appearance came from that pen+ink combo. Which lead me adopt the 61 as my travel pen - no need to carry an ink vial for short jaunts.

Bye,
S1

I hadn't quite talked myself into a 61 with a capillary filler yet, as I wasn't sure if such a filling system would be practical. You've given me a reason why it might be. Hmm.

July 11, 2015

If one is profoundly curious to determine just how much ink a c/c pen will hold when the reservoir is empty, I suggest weighing the pen without the reservoir before and after filling: the difference in mass will translate to the amount of ink in the pen feed+collector: ~1 gram per milliliter.

Good advice on weighing the pen to know how much ink there is. Just weighed my Vanishing Point nib unit with a Con 20 converter. Since I can't see the ink level, I now know it weighs 6.2 grams empty, and 7.3 grams full.

Edited July 12, 2015 by Tasmith