Latex Sacs - Longevity

[Bibliophage]

I realized that the latex sacs in my repair box are about 10 years old. (still in a ziplock bag)

 

My question here is:

 

Should I order some new sacs before repairing some Wearever and Esterbrooks, or are the ones I have likely to be just fine?

 

This came up because I just received an E-Bay lot that needs service. The Parker 21's hold liquid, but are .. deteriorated. One is almost completely black - you can only see through it with a bright light behind it. So I'm going to be ordering some PVC sacs to re-sac the Parkers.

 

(The Parkers will be a separate post. One is a typical Parker 21, but the other is... odd. )

 

 

[txomsy]

Others may give better advice, but from my experience with rubber sacs... they last a lifetime.

[eharriett]

Like txomsy says, others may give better advice, but to me 10 years is probably fine assuming they've been stored properly. They're expected to last at least 10 years in a pen with liquids. I mean, you might be looking at a slightly reduced lifetime of a repair once the sacs are in the pen, but usually if I'm buying one, I will replace it anyway unless the person I buy it from is known to me for good restoration work. If the sac feels good, it probably is.

[Addertooth]

...and ink used is reputed to affect lifespan.

[Bibliophage]

Okay - so the five I have are likely okay, so I don't have to buy additional #16's unless I have more than five pens. (which, I believe I do, as the wearever _also_ use a 16)

 

They've been in the ziplock bag, in a fishing tackle box, for a decade. So they've been in the dark and while not completely climate controlled, not outside. (In a room of the house where we keep the vent shut off, for storage)

[Bibliophage]

Oh - one of the resacs will be an Esterbrook. The original sac is actually in fantastic shape, and you can clearly read the yellow ESTERBROOK printed on the side. I'd just rather replace it and know that the sac is a _bit_ newer than 65 years.

[txomsy]

Me, I wouldn't.

 

If it looks good, I'd first try to fill it with water and watch out for any leaks. If there is none, then I'd just use it. I've got some pens with original sacs dating from the 50's or earlier. It's nicer to enjoy the original sac (from my most shortsighted point of view). I've also got a Parker converter that must be from the mid-80s, that has rested unused since the 90's and still works like new.

 

But it is your pen, and if it makes you feel more comfortable, then, me, I can see no reason for you not to do it.

[eharriett]

My vote is to replace the sac anyway, even if you think it is good. First of all, Esterbrook's sometimes did not use latex, depending on war and other supply shortages, so the material may not be what you think.

 

But second of all, and much more importantly, while I'm not necessarily a subscriber to the theory that some inks aren't good with sacs -- I haven't had problem, myself, and I'm pretty hard on my ink sacs -- I cannot deny the experiences of those who have had the problem. But more to the point, ink today is definitely a lot more --- inky -- than inks of yesteryear. And a sac of that age may not be able to handle any of the modern inks, even the easy ones like Waterman and Pelikan. Change it. Keep the old one as a display piece if you want.

[Ron Z]

The ironic thing is that Esterbrook sacs seem to be tougher than ones used by any other manufacturer. They do fail eventually, but they are one of the few pens in which I find original sacs that are still working.

 

I bought a bunch of pens that came out of the estate of a guy who was a Chemical Engineer for Esterbrook. In the batch of pens were a few with a stamping that said "Project 61." Pure speculation, but given his work, I wonder if Esterbrook was testing a formula for the sac rubber, so they made sacs, put them in a pen, and just used the pens to see how long they lasted.

 

My general practice is to replace sacs when I buy pens. But if you can do it yourself and are OK with the risk of a leak, why not try using the sac for a while and see how long it lasts.

[Bibliophage]

I won't try to repair a Vacumatic, Snorkel, or any of the variety of more complex mechanical fillers, but I feel confident in my ability to warm a pen, pull off a sac, and re-sac (In fact, they're all dismantled right now, other than the Esterbrook with the good sac. That one is apart, but I haven't pulled the sac off of the section) I just hadn't done it because I never had the shellac around. I just finished shellacking a desk, so I have a third of a can of thinned down amber shellac left over.

 

As for a leak? I'm not worried about the _ink_, I just don't want another colour changed celluloid(ish) pen. The ones I have, I should put up for parts for other folks. I wonder if waxing the inside of the barrel would hurt it? (maybe beeswax)

 

Ron - thanks for the information. So you also think my 10 year old, still in the bag sacs are probably fine?

[Ron Z]

Don't wax the inside of the barrel. You don't need to. I was talking with Peter Amis, who owns the Pen Sac Company. Peter says that the modern formulation of the latex used will not harm the color of barrels.

 

Are the sacs OK? Likely, but I don't think that we have any real idea what the life span of the modern material is, so don't hold me to that!

[Bibliophage]

Don't wax the inside of the barrel. You don't need to. I was talking with Peter Amis, who owns the Pen Sac Company. Peter says that the modern formulation of the latex used will not harm the color of barrels.

 

Are the sacs OK? Likely, but I don't think that we have any real idea what the life span of the modern material is, so don't hold me to that!

I was talking about the ink soaking into the celluloid if the sac ruptures. The waxing was just an idle musing.

 

It could be that the pens I have that are seriously discoloured are casein.

[Ray-Vigo]

I would love to see some kind of study as to whether Peter's assertion is true. I heard the late Bert Heiserman (a great guy, miss him and his shop) say the same thing some years ago - that the modern version of the latex sac should not discolor the celluloids that tend to discolor when the sac goes bad. I use the new formulation silicon (non-PVC) sacs in some of my pens. But from a functional standpoint, the latex is a much better sac. The only issue is the concern about discoloration. But if the new latex sacs are color-safe, then they are the way to go. I just haven't seen solid proof in either direction - just what the suppliers and veteran repairmen tell me.

[Bibliophage]

I guess a lot depends on the vulcanization process used on the latex. I assumed that the Pen Sac company was using the same process as the old company did.