Reducing Nib Dry-Out With Rubbery Sealant?

[Noihvo]

Some silly US law said the cap had to have enough holes or a big enough hole in it that small children would still be able to breath a bit when they swallowed a fountain pen cap....

 

I'd read a number of posts about that.

It's so stupid, I don't think it's a myth. It sounds something like a ball point using law maker would do.

 

[praxim]

I doubt that the people who put holes in caps of early 20th C pens were jotting design notes with ballpoints dropped through a time warp from decades in the future, nor even fussing much about what children ate so long as they ate everything on their plate.

[Ron Z]

 

Some silly US law said the cap had to have enough holes or a big enough hole in it that small children would still be able to breath a bit when they swallowed a fountain pen cap....

 

Parker Vector. Nope, no vent hole. Bexley Demeter - nope, no vent hole. Pelikan M200 - nope, no vent hole. Some air gets round the cap, but the kid won't get enough air to breathe. No vent hole in the 600, 800 or 1000 series pens either. Kaewco DIA - nope. Kaweco Elite - nope. Kaweco Sport? No vent hole. Parker Big Red RB/ballpoint - nope. Sheaffer Legacy, Sheaffer Connaisseur, Sheaffer Imperial, Sheaffer No Nonsense - no vent hole.

 

Conclusion? I think its safe to say that its a myth.

 

I suspect that the reason that the vent hole is less common on modern pens is that the feed does a much better job of controlling ink flow, so is not needed. The Parker 51 was IMO the pen that turned the corner with its very fine collector and feed. Machined to much closer tolerances than the earlier pens, it demonstrated that good ink control with variations in pressure was possible.

[dumaresq]

Thanks for all the input so far -- I'm proceeding with caution!

Because the pen I'm thinking of performing this on has a wooden cap, I suspect the air is leaking right through the cap walls (even before the threads become a factor). A Smug Dill's water test supports this theory.

Hence my plan to focus on the inner cap (which is intact, no cracks), and seal the air off right there, eliminating all other downstream factors.

Seems like an O-ring, as suggested by Ron Z and Noivho, is also an option. I've ordered a couple of sizes to play around with.

Still, I like the idea of piping a ring of sealant. If it works, it could be a readily transferable method. I am aware that the actual applying of the sealant may be a huge challenge though! And durabality remains to be seen.

Whatever it is, I’ll experiment on a cheap spare pen first. I have a couple with transparent caps – these should be good for showing how the sealant/O-ring engages the pen section when capped.

Does anyone know what might be a good sealant to use for this purpose? There seem to be so many varieties.

(Although Bo Bo pooh-poohs my idea, I know where he's coming from, I have the same doubt myself!!)

[Ron Z]

I would think that any RTV (room temperature vulcanization) silicone rubber would work. It remains flexible even after curing. Give it 48 hours. maybe more, before you try it.

 

If you think that the wood cap is drawing off the water in the ink, I wonder if coating the inside of the cap with spar varnish (used on boats and outdoor furniture) would seal the wood and keep it from absorbing moisture. Use a cotton swab to apply. The varnish would also protect the wood from rotting over time.

[tim77]

Is the inner cap not meeting the section? Can it be removed and re-seated?

Its going to awfully difficult to create an even bead of rubber around the mouth of the inner cap. But it might be possible to re-glue it into the outer cap so that it fits closer over the nib.

[A Smug Dill]

If you think that the wood cap is drawing off the water in the ink, I wonder if coating the inside of the cap with spar varnish (used on boats and outdoor furniture) would seal the wood and keep it from absorbing moisture. Use a cotton swab to apply. The varnish would also protect the wood from rotting over time.

Would beeswax dissolved in mineral or coconut oil work as the varnish?

 

Is the inner cap not meeting the section?

Can't see through the opaque wooden cap to determine that with any confidence.

 

Can it be removed and re-seated?

There seems to be no way to gain purchase on the inner cap to pull it out, at least not without using something like a metal scribe with a sharp point to dig into the plastic and risk significant damage to it.

Edited October 18, 2019 by A Smug Dill

[Ron Z]

 

There seems to be no way to gain purchase on the inner cap to pull it out, at least not without using something like a metal scribe with a sharp point to dig into the plastic and risk significant damage to it.

 

 

Try an inner cap puller.

 

Bees was dissolved in naptha maybe. Mineral oil is too heavy, and I would never use a biological oil like coconut oil in a pen.

[tamiya]

Rather than bringing out the big caulk guns first off... why not try sealing the nib in cap with something temporary to test?

 

I'd chop finger tip off a rubber/nitrile glove perhaps, put that over the nib then cap it for a night/week/month/etc see if it really stops drying out.

 

 

That said, I bought a Platinum Desk Pen earlier this year... came with a cartridge of their fabled Carbon ink so I popped that in & whoops didn't even bother flushing the brand new pen (hey I was overseas travelling!). It flew back with me and I've used it to jot short notes every day or 3, mainly writing on paper labels.

 

Still writing fine today! Starts immediately no drama. 1 cartridge, 10mths later.

Can't see level in cartridge as its black all inside.

 

 

Then again I've got Pilot V-Pens sitting in my pen cup which starts fine every time I try them too.

They've been there since mid 1980s.

[hari317]

 

 

 

 

Can't see through the opaque wooden cap to determine that with any confidence.

 

 

 

mark the level the cap lip makes against the barrel with cap closed fully.

A = measure the length of the section lip from this mark.

B = measure the depth of the inner cap lip from the cap lip.

 

if A is less than B, the inner cap is not touching the section lip in cap closed position.

 

HTH.

[SoulSamurai]

That said, I bought a Platinum Desk Pen earlier this year... came with a cartridge of their fabled Carbon ink so I popped that in & whoops didn't even bother flushing the brand new pen (hey I was overseas travelling!). It flew back with me and I've used it to jot short notes every day or 3, mainly writing on paper labels.

 

Still writing fine today! Starts immediately no drama. 1 cartridge, 10mths later.

Yeah, my Platinum Carbon desk pen with Carbon ink is extremely resistant to drying out. It's one reason why I like Platinum so much.

[tamiya]

Yeah, my Platinum Carbon desk pen with Carbon ink is extremely resistant to drying out. It's one reason why I like Platinum so much.

Why is that? we've got a flock of Platinum Preppies inked up, but those will dry out a full fill in about 4-6wks. Preppy has inner cap, looks like decent seal afaik.

 

Is it the ink? It seems oilier, never fails to impress how fast it dries once written & stays water fast.

 

Truth be told I've been waaaaaiting for it to run out so I can give it a wash. My Platinum Carbon desk pen has a weird musky "wet dog/sneaker foot odour" smell... dunno if it's the ink's solvents or there's some funky biology going on. But it hasn't run out or clogged up, so I don't want to disturb this reliable jotter.

 

Also curious if the cartridge ink is same as bottle... think I bought a pack of extra carts & also acquired bottle of Platinum Carbon. Might back2back bottle fill vs cartridge - I've got a 2nd Desk Pen to match. Want to try Carbon ink in a Pilot Metro perhaps, see if that slows down dry out.

[txomsy]

On a side note, wasn't the early "safety" pens designed this way? I do not mean the ones with retractable nibs (which also sealed) but some safeties where the grip section ended in a rim that was intended to seal with the inner cap when the cap was screwed in. The idea being that this would contain ink spills and avoid the grip being stained when the pen was open.

 

As for the hole, originally, as far as I understand (and I may be wrong --and have often been), was a means of avoiding ink spills, not only due to pressure changes, but also because if the cap seals tightly against the section, when pulling it out you would produce a void that might suck ink and produce a spill. This would avoid the issue. Nowadays, the hole -specially on BICs- is patently wider in some caps to allow respiration in case of swallowing.

 

Finally, as for the idea, I think is worthy but mostly on screw-on caps, There are pens (I remember some chinese ones) that do actually seal tightly the cap against the section/body either snap-on or screw-on, so the idea has merit. There are pens also that keep a humidor on the cap (a water reservoir) to avoid drying. I would expect that a snap-on cap can make a greater void when removed, specially because they snap through some resistance and to overcome that resistance you pull strongly. A screw-in cap would be removed slowlier and allow for air to equilibrate as soon as a "corridor" is created between the threads on unscrewing. But that is only my lay opinion (and as mentioned I am often proven wrong).