Bad Sac In A Snorkel

[Goncharov]

Something odd happened when I tried to flush one of my snorkel pens yesterday. It blew bubbles when I went to fill it with distilled water, but no water came out afterward. After a couple tries, I realized that the pen just wasn’t filling. I unscrewed the barrel, and saw some blue ink on the spring and sac protector. A bit more ink had pooled in the section.

 

The little bits of the ink sac that I could see looked rather odd, so I removed the sac protector.

This is what was waiting inside:

 

http://www.oblomovonline.com/images/snorkel/badsac.jpg

 

 

Those shiny bits (and the black dots on the paper) aren’t ink; they are sticky liquefied rubber.

 

I immediately looked inside all of my snorkel pens; happily, the rest seem normal. I disassembled, cleaned, and resac’d this pen today, and it’s now writing normally.

 

I purchased this pen (as restored) at the end of March. In the four months that I’ve owned it, it has been inked with black Parker Quink, Mont Blanc Royal Blue, and Waterman Florida Blue. I flushed with distilled water between inks.

 

 

What causes this?

Was it a fluke, or are the rest of my snorkels ticking time bombs?

Is there anything I should be doing?

[Ron Z]

There have been bad sacs from one vendor in the past, and this may be one of them. The super flexible sacs sold to use in snorkel, TD and PFM pens seem to be vulnerable. The typical failure mode is meltdown like this, often where the rubber comes in contact with metal.

 

It's also possible that whomever restored the pen used something other powder instead of pure talc to coat the sac.

[jbb]

There have been bad sacs from one vendor in the past, and this may be one of them. The super flexible sacs sold to use in snorkel, TD and PFM pens seem to be vulnerable. The typical failure mode is meltdown like this, often where the rubber comes in contact with metal.

 

It's also possible that whomever restored the pen used something other powder instead of pure talc to coat the sac.

Where do you recommend I buy the sacs and seals to repair a snorkel?

[Goncharov]

 

Where do you recommend I buy the sacs and seals to repair a snorkel?

 

To date, I have bought sacs and seals from two sellers: Pendemonium, and Vintagepens' ebay store. So far, so good.

There are plenty of other sources, of course.

 

I do not know the origin of the sac in the picture.

[Ernst Bitterman]

My default source for snorkel seals is http://martinspens51.com/. Not discounting the others, just adding a data point.

[psfred]

I had several Snorkels do this, the first batch I restored. The sacs died in the drawer, unused. I discovered the problem when I could not get one of them to write for more than a page or two with Noodler's Ottoman Azure, and when I took it apart again the sac was melted. Since I was positive that I had replaced the sac upon getting the pen, I checked all of the Snorkels I've restored and 5 or so of them were rotted.

 

I don't remember where I got the sacs, but I think they were the 14 1/2 thin wall ones, either from Pendemonium or Giovanni, but I'm far from certain on that. Other pens I restored at the same time, including an Imperial TD using a sac I bought a the same time (#15) are fine.

 

I did use baby powder on a couple before I got some talc, but those are still OK.

 

Also had one (and only one) Parker "51" diaphram turn to goo -- of the eight or so others I did about the same time, none are a problem.

 

I suspect a failure in the sac itself, not the ink.

 

Peter

[Goncharov]

I found another failed sac in one of my snorkels today. It was pretty much an exact replay of the last time. This one did have a bit more ink roaming free in the barrel; happily, none of it escaped.

 

I do have one rubber sac left, but I’m hesitant to install it.

 

Has anyone ever tried a silicone sac in a snorkel?

Is there any reason why a #14 silicone sac wouldn’t work?

[viclip]

Silicone sacs are noticeably stiffer than rubber sacs. Odds are the silicones won't compress as readily on the downstroke & thus will take in less ink. Recall that the original rubber sacs used by Sheaffer in Touchdowns & Snorkels, were the thin-wall variety i.e. with the 1/2 numbering. While there may be some debate about how much more ink a thin-wall rubber sac will suck up as compared to a regular rubber sac, nevertheless don't be surprised if the silicone sac results in an appreciable decrease in ink capacity.

[Ernst Bitterman]

I've put silicone in a couple of TDs because I was concerned with the clarity of the ink window, and found that the fill was reduced to about 60% of that a regular latex sac would take. Given the similarity of operating principle, you'd probably see the same reduction in a Snorkel, but given the teeny little amount of ink a Snorkel takes in regularly, you must ask yourself whether saving a sac replacement in a decade or two is worth the increased frequency of filling.