Iroshizuku Kon Peki and Latex Sacs

[Matth13]

I had restored a Sheaffer’s PFM within the last year and fitted it with a brand new latex sac. Over the last year I used it with only one ink, Kon Peki. Last week I noticed it wasn’t filling so I disassembled and the latex sac was partially dissolved! Sort of gooey and stretchy. Has anyone else experienced issues with this ink in latex sacs?

 

 

[mizgeorge]

From memory, Kon Peki is a very alkaline ink, and these generally aren't recommended for latex sacced pens.

 

There are various charts on here where people have measured the exact figures, and I recall KP as coming in around 9.5. I don't generally go above 7 for anything in latex, as well as avoiding any cleaning product that contains ammonia. 

 

You might find this interesting:

 

 

[JakobS]

I have had it happen with Chiku-rin in an Esterbrook J. I honestly should of known better, but wanted to try out the ink. I agree that alkaline inks should be avoided with latex sacs. In the hey day of latex sac usage alkalinity, not acidity was the main issue with sac degradation.  When Sheaffer first introduced their line of inks, they found it to be too alkaline, and changed the formula to what is more familiar to us as their very safe Skrip line....

[Paul-in-SF]

1 hour ago, mizgeorge said:

From memory, Kon Peki is a very alkaline ink, and these generally aren't recommended for latex sacced pens.

So does it (or do any of the other very alkaline inks) come with a warning label? Of course not, somehow vintage pen users are just supposed to know that a) alkaline inks are bad for latex sacs, and b) which inks are alkaline. Is there some compelling reason or benefit for inks to be alkaline in the first place? (I've never heard of this before, but I don't spend a lot of time in the ink forums.)

 

What about silicone or PVC sacs, are they immune to this effect? 

 

(Asking anyone, not just mizgeorge. If I sound angry, it's not at anyone here, unless they work for an ink company that sells these inks without a warning.)

 

(I'm not really angry, just a little SMH.)

[JakobS]

 

    

8 minutes ago, Paul-in-SF said:

So does it (or do any of the other very alkaline inks) come with a warning label? Of course not, somehow vintage pen users are just supposed to know that a) alkaline inks are bad for latex sacs, and b) which inks are alkaline. Is there some compelling reason or benefit for inks to be alkaline in the first place? (I've never heard of this before, but I don't spend a lot of time in the ink forums.)

 

What about silicone or PVC sacs, are they immune to this effect? 

 

(Asking anyone, not just mizgeorge. If I sound angry, it's not at anyone here, unless they work for an ink company that sells these inks without a warning.)

 

(I'm not really angry, just a little SMH.)

 

    The simple historic answer is that inks that were made in western countries that used latex sacs the most tend to make more acidic inks, while eastern countries where latex sac usage was not present in vintage pens, and only very little in modern pens (entry level Pilots, Hero's etc.)  tended to make alkaline inks. This has become a greater issue in modern times as the availability of inks from around the world are relatively easy to acquire. The combination of these inks often becoming fads with other FP fads, such as making these the "inks to have" along with other fads such as "flexible nibs are the best" has given rise to mixing western vintage latex sacced pens with eastern made ink.  I don't know if the companies making alkaline inks are aware of this to a great degree, because their biggest segment of users are based where they have traditionally sold their inks in areas absent latex sacs, and are also predominantly using modern pens that lack a latex sac no matter the geographic area. 

[Paul-in-SF]

Of course that makes perfect sense. I'm still smacking my head a little though. 

[A Smug Dill]

6 hours ago, Paul-in-SF said:

So does it (or do any of the other very alkaline inks) come with a warning label?

 

I find that a preposterous suggestion. It's not like alkaline inks are more hazardous to the health and/or physical safety of users than is either expected or acceptable of writing inks. If it's likely to cause chemical burns on (prolonged?) contact with human skin, then sure, one can reasonably argue a warning label ought to be required. However, even if an ink is apt to discolour the PVD layer or cause pitting of the metal on a nib (however old or new, ‘cheap‘ or precious), or permanently stain the walls of ink reservoirs (whether they are ink cartridges, converters, sacs, or the inside of a piston-filled demonstrators' barrels), or degrade celluloid, or ruin pristine white porcelain basins or expensive quartz countertops on prolonged contact, I don't think there is either a requirement or reasonable expectation that there would be warning labels to advise of such. If anything, it's up to the interested (prospective) user to ask for the Safety Data Sheet from the ink manufacturer or its official distributor, consider the information (presented in however user-friendly or unfriendly a manner) therein, and apply it to his/her own use cases to make a judgment call about suitability.

 

6 hours ago, Paul-in-SF said:

Of course not, somehow vintage pen users are just supposed to know that a) alkaline inks are bad for latex sacs,

 

Nobody else, perhaps except the manufacturers of those vintage pens and/or latex sacs, has an implicit or shared responsibility for educating edge case users on caring for and protecting their writing instruments and private property.

[arcfide]

1 hour ago, Paul-in-SF said:

Of course that makes perfect sense. I'm still smacking my head a little though. 

 

Don't forget that it's not just Latex sacs. It's *extremely* hard for an ink company making inks for their pens, which they test in their pens, to justify the extreme monetary expenditure of certifying their inks' behavior in pens that are no longer even manufactured, and not supported by any major pen company (in general). Pen makers recommend that you use their ink in their pens for just such reasons, and have for pretty much as long as I was able to look up. It's a simple matter of logistics. Some makers, such as Platinum, do have FAQ warnings about some features of their inks, but not relating to Latex Sacs. It's imply so far off their radar that it would be, frankly, very, very weird if they did have such warnings. Afterall, there are some inks that will corrode some plastics or at least, interact poorly with some plastics on some pens, and the same can occur with certain other combinations of pen materials and inks. It's especially more common with boutique inks that are not part of a standard maker's line. One could argue that Pilot's Iroshizuku inks skirt the line of "boutique" inks. Most boutique inks are expected to be higher maintenance, less forgiving, and have some strange edge cases where the pen maker simply can't guarantee behavior. That's the price paid in order to produce the more desirable behaviors that people want. 

 

As for why a maker might go for an alkaline ink, this could at least in part be due to a desire to reduce acidity on the page, due to concerns about excess acid causing issues with longevity. However, I have also heard some hints that the more alkaline ink formulations permit certain properties to be more readily obtained, I think related to flow and possibly durability on the page. Why and exactly what properties you get from this isn't really clear, but Japanese inks seem to, on the whole, be significantly wetter than European inks. It's not clear whether that's a result of their using alkalinity or not. However, on the whole most of the European inks I have seen tend to be drier, and even the really wet inks tend to be, with some clear exceptions, a little drier than the corresponding counterparts. Of course, that's not really saying much. But it's possible that it's easier to get better flow with alkaline compositions. 

 

Likewise, some inks that Japan puts out, such as Kon-peki, are remarkably durable all things considered, and it's not clear how much of that is enabled by alkalinity. I'm sure it's technically possible to achieve something similar in the other direction, but I wonder if there are some trade-offs there, given the general patterns. 

 

Basically, very few pen companies rely on Latex sacs anymore, that I'm aware of, and most inks aren't made to cater to vintage pens. That's not what the market wants. 

[A Smug Dill]

23 minutes ago, arcfide said:

Basically, very few pen companies rely on Latex sacs anymore, that I'm aware of, and most inks aren't made to cater to vintage pens. That's not what the market wants. 

 

🙏🏼  Thank you very much for pointing that out!

[Paul-in-SF]

What I was smacking my head about, really, is not that inks aren't made with the latex sac market in mind, but about the information. The ink mfrs could, of course, be making their ph indexes known, which they don't apparently. Again, not their target market, and if ph is irrelevant to every aspect of fountain pens other than latex sacs, fair enough. 

 

And of course it's no-one's responsibility to provide general information. I was just a bit gob-smacked to find this fairly important fact dropped into a thread. "Wait, what? Holy cow, how did I not know that? How did that not come up before in anything I've read?" That sort of thing. Of course, I'm grateful to mizgeorge for mentioning it. It makes me wonder if I'm the only one who didn't already know. 

 

Assuming I'm not the only one, I wonder if it wouldn't be worthwhile to put a quick mention of ink ph issues as a sticky in, say, Repair Q&A and Inky Thoughts. Since there isn't a forum dedicated solely to "vintage pens with latex sacs" those seem likely spots for the information. Just a thought. 

[arcfide]

11 hours ago, Paul-in-SF said:

What I was smacking my head about, really, is not that inks aren't made with the latex sac market in mind, but about the information. The ink mfrs could, of course, be making their ph indexes known, which they don't apparently. Again, not their target market, and if ph is irrelevant to every aspect of fountain pens other than latex sacs, fair enough. 

 

And of course it's no-one's responsibility to provide general information. I was just a bit gob-smacked to find this fairly important fact dropped into a thread. "Wait, what? Holy cow, how did I not know that? How did that not come up before in anything I've read?" That sort of thing. Of course, I'm grateful to mizgeorge for mentioning it. It makes me wonder if I'm the only one who didn't already know. 

 

Assuming I'm not the only one, I wonder if it wouldn't be worthwhile to put a quick mention of ink ph issues as a sticky in, say, Repair Q&A and Inky Thoughts. Since there isn't a forum dedicated solely to "vintage pens with latex sacs" those seem likely spots for the information. Just a thought. 

 

I think partly the question of pH in this context is a little overblown. Yes, the pH appears to matter, but I think I've read somewhere that it isn't necessarily just a matter of pH, or even that pH is an inherent element. As far as I understand it, a lot of it has to do with the dye concentration, with heavily saturated dye-based inks being more likely to negatively affect Latex sacs and other pen parts, even if those inks are not particularly alkaline. Apparently there are some inks that are super saturated that will also ruin sacs but that are not particularly alkaline. I don't recall at the moment where I read this though. 

 

In short, pH *is* talked about by the ink makers. I believe I've seen officially FAQ documents or information from Sailor, Platinum, and Pilot that have talked about the pH of their inks, as well as Herbin and Noodler's. So, it's not hidden information, per se, but it's also not a big advertising point, either, except for neutral-pH inks. If your inks aren't neutral-pH, it tends to be a marketing issue to put that on the bottle, even if it probably doesn't matter. Makers who do have neutral-pH have a tendency to market that fact a little more prominently, IME. 

 

There have been articles from various respected authorities in the pen world on the "myth of ink pH" and the like, pointing to the saturation level as being more critical to the health of pens. 

 

I think maybe one reason that people don't talk as much about the latex sac thing is that it *is* a little bit of an old hat topic at this point, because Richard Binder's "Good, Bad, Ugly" article on inks discussed it many years ago and that's often one of the "first" ink pages that people see. There's plenty of room to disagree with Richard's article on some points, but on the whole it's a good starting point:

 

Inks: Good, Bad, and Ugly (richardspens.com)

 

I think this article is readily linked throughout FPN. 

 

So, in short, putting pH levels on the bottles wouldn't necessarily get you information that isn't already available from the maker through their other standard channels, but it also wouldn't necessarily give you the green light to use an ink either, because pH isn't the only way to destroy a latex sac with widely available ink. 

[A Smug Dill]

4 hours ago, arcfide said:

In short, pH *is* talked about by the ink makers.

 

Colorverse also publishes the pH value of its inks, but I'm glad it doesn't — and I don't think an ink manufacturer selling to a broad market should — make any statements in relation, or couch that information as having any relevance, to whether it's safe for ‘your’ pens, ‘vintage’ pens, or any particular pens it doesn't produce and offer commercially.

[Karmachanic]

Hmm. It seems that CC pens allow one to be quite reckless in ones choice of ink.

[A Smug Dill]

7 minutes ago, Karmachanic said:

It seems that CC pens allow one to be quite reckless in ones choice of ink.

 

The ‘right’ attitude towards pens as mere tools, and sacs and converters as consumable and replaceable parts, allows one to be quite ‘reckless’ in one's choice of ink for enjoyment of what one owns.

[Karmachanic]

Yes dear.

 

 

[JakobS]

4 hours ago, A Smug Dill said:

 

The ‘right’ attitude towards pens as mere tools, and sacs and converters as consumable and replaceable parts, allows one to be quite ‘reckless’ in one's choice of ink for enjoyment of what one owns.

 
Historically, latex sacs have the expectation of being as consumable or replaceable as a car engine would be. Before the early 2000’s when more saturated and alkaline inks became available in the West, FP users and pen repair people rarely had latex sacs fail before a decade plus of use. Esterbrook sacs were known to last 20-30+ years, compared from a month to a couple years when using saturated or alkaline inks. The majority of vintage sacced fountain pens have friction fit sections that need to have heat applied to open, and are not meant to be opened as often as these sac failures will cause.  The wear and tear from repeated opening, and heat on the section will cause it to lose its friction fit overtime. The pen barrel will also have an increased likelihood of warping overtime from the repeated application of heat. So if you are looking at a fountain pen as a tool to write with, as you would a car as a tool to reliably drive somewhere, you don’t want to have to replace its engine every couple months or years to do so. Neither ever were made with the expectation to do so. That’s probably the main reason it took Sheaffer four years after its first attempt at ink to produce Skrip, they knew they had to get it right the second time, because FP users and pen manufacturer's expectations would not allow them a third chance.

   Now should modern ink manufacturers be held to an expectation that they should know and caution about this issue? Wouldn’t that be something, but I’m a too jaded to believe anything other than a corporation only exists to make a profit for their shareholders, and nothing else, so I depend upon my own research to ferret out what I need to know. Being around this community for over a decade also allows me to pick up on trends and how they started, so caution signals pop up when a new ink comes along as the new flavor of the month.

  It has been a few years since alkaline and saturated inks have been connected to sac failure so it’s not that new, nor difficult to read about.