What Liquefied This Sac?

April 30, 2014

There was an 'event" with poor sacs which all did that. I bought 50 or so and am still stumbling across them as I rotate old pens into my circulation. Nothing to do with inks on this issue. I dont recall who I bought the sacs from, but it was all over the internet at the time (ca 10 years ago if I recall correctly)

July 5, 2015

I would like to note here that, after over two years, I have failed to prove anything. None of the current samples in Noodler's Blue have deteriorated after a year as did the first (solitary) sample. I would like to have re-designed the experiment in light of Ron's criticism, but I was not willing to make the considerable effort, given what I believe to be the absolute requirement of using fragments of the same sac (not two sacs ostensibly from the same batch) in both the treatment and control runs.

With Snorkel-fillers in particular, owing to the risks and effort required to change the sac, I think the Woodbin "silicone" sacs are a good idea, apparently without the gas permeability suffered by the pure silicone sacs. I have a Woodbin "silicone" sac on one of my TD's as well, though I worry about the possible long-term effects on the sac nipple.

July 6, 2015

With Snorkel-fillers in particular, owing to the risks and effort required to change the sac, I think the Woodbin "silicone" sacs are a good idea, apparently without the gas permeability suffered by the pure silicone sacs. I have a Woodbin "silicone" sac on one of my TD's as well, though I worry about the possible long-term effects on the sac nipple.

I agree. I quite using latex sacs in any Sheaffer pneumatic filler two or three years ago. No exceptions. I tried the Vintage Pen silicone sacs, and had maybe half a dozen pens come back. The Woodbin sacs are THE item to use on the Sheaffers. I would question any pen mechanic who does not use them because the risk of damage to the internal parts (springs in snorkels especially) when the sac fails is too great.

July 7, 2015

I agree. I quite using latex sacs in any Sheaffer pneumatic filler two or three years ago. No exceptions. I tried the Vintage Pen silicone sacs, and had maybe half a dozen pens come back. The Woodbin sacs are THE item to use on the Sheaffers. I would question any pen mechanic who does not use them because the risk of damage to the internal parts (springs in snorkels especially) when the sac fails is too great.

Hi Ron, I tried a silicon sac on a thin model snorkel and I can't get it to fill. I can't even feel a trace of air when I depress the plunger with the snorkel close to my top lip. I have two theories, the reason for changing to silicon was that the latex sac went gooey and left a terrible sticky mess in the sac guard. Perhaps I haven't cleaned the sac guard sufficiently (tried hard using a small barrel brush etc) and the silicon sac is sticking to it. Second theory is that silicon is thicker than latex and doesn't have the same collapsible qualities when filling. My silicon sac didn't come directly from Woodbin, perhaps I should try some as per your recommendation.

Edited July 7, 2015 by adyf

July 7, 2015

I used the silicone sacs from Vintage Pens, and the pens filled just fine. The reason that I quit using them is the air permeability issue.. They're not the cause of your problem.

I wouldn't expect you to be able to feel the air at the end of the snorkel tube. I would suspect that the issue is an air leak somewhere. Do you hear a "chiff" at the back end when you push the plunger down? Do you get bubbles out of the snorkel tube and nowhere else when the pen is immersed in a glass of water? Check those things first.

There is the chance that goo may be in the sac guard, and if stuck it could pinch or buckle the sac. Use naphtha, or mineral spirits, or even WD-40 (yuck, I hate the smell) to soften and remove the goo with a cotton swab. Then clean well with alcohol if you used anything other than naphtha.

Richard Binder and I had a rather large bag of OEM latex sacs from the Sheaffer service center. I can assure you, they were not thin walled or super flexible, but regular sacs. The pens filled just fine. There is more than enough air pressure to squeeze the sac. A thin walled or super flexible sac may not fill as well because it can't pop back to shape and pull the ink in as easily.

July 7, 2015

I used the silicone sacs from Vintage Pens, and the pens filled just fine. The reason that I quit using them is the air permeability issue.. They're not the cause of your problem.

I wouldn't expect you to be able to feel the air at the end of the snorkel tube. I would suspect that the issue is an air leak somewhere. Do you hear a "chiff" at the back end when you push the plunger down? Do you get bubbles out of the snorkel tube and nowhere else when the pen is immersed in a glass of water? Check those things first.

There is the chance that goo may be in the sac guard, and if stuck it could pinch or buckle the sac. Use naphtha, or mineral spirits, or even WD-40 (yuck, I hate the smell) to soften and remove the goo with a cotton swab. Then clean well with alcohol if you used anything other than naphtha.

Richard Binder and I had a rather large bag of OEM latex sacs from the Sheaffer service center. I can assure you, they were not thin walled or super flexible, but regular sacs. The pens filled just fine. There is more than enough air pressure to squeeze the sac. A thin walled or super flexible sac may not fill as well because it can't pop back to shape and pull the ink in as easily.

Thanks Ron, I'll try and acquire some naphtha.

July 7, 2015

I used the silicone sacs from Vintage Pens, and the pens filled just fine. The reason that I quit using them is the air permeability issue.. They're not the cause of your problem.

I wouldn't expect you to be able to feel the air at the end of the snorkel tube. I would suspect that the issue is an air leak somewhere. Do you hear a "chiff" at the back end when you push the plunger down? Do you get bubbles out of the snorkel tube and nowhere else when the pen is immersed in a glass of water? Check those things first.

There is the chance that goo may be in the sac guard, and if stuck it could pinch or buckle the sac. Use naphtha, or mineral spirits, or even WD-40 (yuck, I hate the smell) to soften and remove the goo with a cotton swab. Then clean well with alcohol if you used anything other than naphtha.

Richard Binder and I had a rather large bag of OEM latex sacs from the Sheaffer service center. I can assure you, they were not thin walled or super flexible, but regular sacs. The pens filled just fine. There is more than enough air pressure to squeeze the sac. A thin walled or super flexible sac may not fill as well because it can't pop back to shape and pull the ink in as easily.

So, the silicone sacs from Vintagepens are the ones to use on Touchdown fillers?

I like the Touchdown fillers, but not the Snorkels, and I have some old Cadets and Imperials that will probably need overhaul soon. The last time I resacked some of the Touchdowns I read that silicone was too stiff for the Touchdown to compress it, so I used the latex. Well, it's good to know the latest opinion. Will the silicone sacs last longer than latex?

Also, what to use on lever-filling Cadets? I bought two of these a few years ago NOS. Presumably they will need resac soon.

July 7, 2015

So, the silicone sacs from Vintagepens are the ones to use on Touchdown fillers?

Vintagepens is the source for pure silicone sacs. Woodbin is the source for "silicone" sacs. The latter aren't really silicone, but they do have their applications. I guess the thinking is that they are PVC. In particular, for Snorkels and TD fillers, Ron is recommending the Woodbin "silicone" sacs. I use the Vintagepens pure silicone sacs for pens that are at risk for discoloration and which are worth trying to preserve.

Ron's write-up on the subject

David Nishimura's Summary

Edited July 7, 2015 by mhosea

July 11, 2015

Thanks Ron, I'll try and acquire some naphtha.

Turned out to be a blocked snorkel tube and nothing to do with the sac........

Apart from snorkels, would silicone sacs be ok on other pens such as the CS58 and Esterbrooks? I do like the option of using more saturated inks with vintage pens occasionally and I'd like to start using silicone sacs where possible/advisable.

Edited July 11, 2015 by adyf

July 11, 2015

That's a decision that you need to make. All three types of sac (latex, silicone and "silicone" i.e. PVC) have their strengths and weaknesses. Take a look here for more information.