Inks That Eat Sacs

[Uncial]

There are a lot more blogs and sites that catalogue ph ink values since this thread began. It's a bit confusing though as not a single tester seems  to match another and some list iron gal inks as pretty close to battery acid, which is plainly ridiculous. There are a couple here from a while back, but I've never been able to find them again. Inkdependence has a list, there are a few other blogs and sites if you google ink ph values, and reddit has a load too. You can see some basic trends even though none seem to produce the same results. Apart from Havana brown, most Waterman inks are surprisingly acidic. 

 

With such a huge variance of results (some not even remotely close to each other) I don't put much faith in it now I'm afraid. Having had sacs and one vacumatic sac unit turn to literal goo in a drawer, never having seen ink, makes me suspect ink may have nothing whatsoever to do with it. I have a sac pen that belonged to my grandfather. It's had all manner of inks in it down through the decades. To my knowledge he never changed the sac, my father certainly didn't when he used it, and I never have. It's still going strong with no problems, but there are more modern sac pens that I've changed the sacs on more than once in the last five to seven years. But my 'anecdotal' observations will continue to be strongly refuted by some.

[Nellie]

Thank you @Uncial! I've actually concluded that acidic isn't bad, just akaline 😀. And at some point I even thought the more acidic, the better and was getting worried about e.g. the Diamine Syrah that I am still going to put in my other Snorkel because that's close to neutral 😆. 

I used to put anything in my Snorkels - and the sacs seem to have lasted around six years - but seeing as this may well be the PFM's last sac, I want to be as careful as I can bear (eradicable blue ink is out!!). I've once even had a sac fail in that pen right after Binder had put it in, but that was a bad batch of sacs, apparently.

[Shinyblue]

It would be useful if people kept an overview of ink and pen/ink sac combinations that were not a success.

 

My recent bad experience was a Sheaffer Touchdown with an Italian red ink called Parafernalia (not being manufactured anymore). Funnily I use the same ink in an Esterbrook SJ and absolutely no issue - both were filled more or less at the same time.

 

That makes me think about the original post and disregarding all the theories about acidity of the inks. The metal sleeve of Sheaffer Touchdowns and Snorkels might be a factor in the sac not lasting as long as one would expect. Perhaps the ink type, the ink sac itself and the metal combined cause a reaction that creates a melted sac.

[Sholom]

The theory that contact with metal may hasten sac deterioration is  maybe plausible. It is known that copper ions can cause that, and that copper phthalocyanine dyes had to be specially purified before Parker could start using them in its inks back in the 1940s. Stainless steel should not be a problem, nor should aluminum, and I think nickel is unlikely to be but I'm not sure. Brass and bronze have copper in them and any signs of corrosion might be a hazard to latex sacs.

The times I've had sacs decompose on me were either when the ink was mostly dried out in the sac (I ink too many pens at once) or from when there was a suspect batch of sacs running around awhile back.