how to keep sac supple for longer?

Hi all,

Found a Sheaffer 350 from the bottom of my drawer - haven't touched the pen for
2 years and I picked it up and try lifting the lever to see if the sac is still
working - well it wasn't. I remember quite clearly that I replaced the sac a
little less than 3 years ago. Now, I have not been very careful with this
particular Sheaffer and I didn't rinse it out before I put it away - was it why
the sac went cracked so soon? I also have other questions:

(1) how long do sacs normally last?

(2) what are the things I can do to make the sacs remain supple for longer?

Cheers,
Ada

Ada Ma wrote:

Found a Sheaffer 350 from the bottom of my drawer - haven't touched
the pen for 2 years and I picked it up and try lifting the lever to
see if the sac is still working - well it wasn't. I remember quite
clearly that I replaced the sac a little less than 3 years ago.
Now, I have not been very careful with this particular Sheaffer
and I didn't rinse it out before I put it away - was it why the
sac went cracked so soon? I also have other questions:

(1) how long do sacs normally last?

(2) what are the things I can do to make the sacs remain supple
for longer?

Hi Ada,
I'm wondering if the sac was one of the defective ones from Woodbin? A
few years ago, the company produced a batch of sacs from bad rubber.
Those sacs went kapoot very quickly. I don't know what would make an
otherwise well-made sac go bad so quickly (good sac should last 10
years or more). Can't imagine leaving the pen filled with ink (although
not a good idea for other reasons) would make the sac go bad. -- B

On 31-Jan-2005, "BL" wrote:

Ada Ma wrote:

Found a Sheaffer 350 from the bottom of my drawer - haven't touched
the pen for 2 years and I picked it up and try lifting the lever to
see if the sac is still working - well it wasn't.
SNIIP
Hi Ada,
I'm wondering if the sac was one of the defective ones from Woodbin? A
few years ago, the company produced a batch of sacs from bad rubber.

I have a nice little Parker True Blue that had one of these defective sacs.
They do not fail like an old sac does; instead, they turn to goo in the
barrel. Apparently something was left out of the mix and those sacs didn't
cure properly. They are a bear to clean up.

Back to Ada's pen: How did the sac fail? Turn to goo or become dried-out
and brittle? If dried-out and less than 10-15 years old, I'm at a loss for
what could cause that.


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L wrote:

On 31-Jan-2005, "BL" wrote:


Ada Ma wrote:


Found a Sheaffer 350 from the bottom of my drawer - haven't touched
the pen for 2 years and I picked it up and try lifting the lever to
see if the sac is still working - well it wasn't.

SNIIP

Hi Ada,
I'm wondering if the sac was one of the defective ones from Woodbin? A
few years ago, the company produced a batch of sacs from bad rubber.


I have a nice little Parker True Blue that had one of these defective sacs.
They do not fail like an old sac does; instead, they turn to goo in the
barrel. Apparently something was left out of the mix and those sacs didn't
cure properly. They are a bear to clean up.

Back to Ada's pen: How did the sac fail? Turn to goo or become dried-out
and brittle? If dried-out and less than 10-15 years old, I'm at a loss for
what could cause that.



Well, the sac didn't go to goo. It became sort of dried out - but it's not
totally brittle, the broken sac is still springy at places. I have no idea why
it happened. I think - I can be wrong - I bought the sac a few years ago
(2001?) from the London Pen Show. Last night I managed to pull out most of the
remains using the tweezers I normally use to pluck my brow and replaced it with
another sac from the same batch as I don't have anything else. The good thing
about these sacs though, is that the opening is so tight that I don't need to
use any glue to keep it on the section (is that part called section?) If I had
a better pair of tweezers (those pointy ones) the whole sac-replacing process
would take less than 5 minutes because no glue drying is needed.

One more question - the new sac I put in is sort of flat, possibly because it's
been sitting around for some time. Would the ink capacity be limited because of
the sac's flatness? If so, do I need to give the sac a bit of pulling
exercises, or may be even blow it up like a balloon, before I fit it on the section?

Ada Ma wrote:
... I don't need to use any glue to keep it on the section
(is that part called section?)

nipple

If I had a better pair of tweezers (those pointy ones) the
whole sac-replacing process would take less than 5 minutes
because no glue drying is needed.

I'd still use a little shellac to prevent the sac from pulling off.

One more question - the new sac I put in is sort of flat, possibly
because it's been sitting around for some time. Would the ink
capacity be limited because of the sac's flatness? If so, do
I need to give the sac a bit of pulling exercises, or may be even
blow it up like a balloon, before I fit it on the section?

Those sacs just don't sound right to me. I think they're defective. Why
would a lightweight piece of pliable rubber flatten out like that?
Sounds like the rubber is breaking down. Bet this new one will fail in
no time *flat* too. Don't bother blowing the thing up unless you can
get the whole operation on a dig movie camera and post a link here...
I'd pay to see that one. Good luck, Ada. Want me to send you some
good sacs? -- B

"BL"

I'd still use a little shellac to prevent the sac from pulling off.


Some of us use clear fingernail polish also...

Those sacs just don't sound right to me. I think they're defective. Why would
a lightweight piece of pliable rubber flatten out like that? Sounds like the
rubber is breaking down. Bet this new one will fail in
no time *flat* too.

I could not agree more, though this does not sound like the Woodside sac's, it
does not seem worth the time and effort to use these, and I would follow up
that recommendation to get new sac's.

You are right, if the sack is a neck type, it should fit tight enough not to
need shellac or nail polish. One of the main problems with these sacks is
that the oils in whoever fitted it's hand attacks the rubber in the sack
(not absolutely sure about this, it might be that it is attacking the
sulphur in the latex) and causing it to go hard.

All the experts say to put the sack in french chalk (I think they mean
talcum powder?) after you buy them to prevent this. You just put a tiny
amount in the bag or box where it is being stored and shake it around a bit.

Maria Ripanykhazova wrote:
You are right, if the sack is a neck type, it should fit tight enough
not to
need shellac or nail polish.

Regardless of the type of sac (neck type or straight sac), a little
shellac or nail polish provides a huge amount of insurance at an iddy
biddy bit of cost against seepage/dislodging.

One of the main problems with these sacks is that the oils in whoever
fitted it's hand attacks the rubber in the sack (not absolutely sure
about this, it might be that it is attacking the sulphur in the
latex)
and causing it to go hard.

This is an interesting theory, Maria, but I've never heard or read
about this before. Where can we find more information about this (oils
in human hands causing rubber sacs to ossify)?

All the experts say to put the sack in french chalk (I think they
mean
talcum powder?) after you buy them to prevent this. You just put a
tiny
amount in the bag or box where it is being stored and shake it around
a
bit.

Talcum powder is used to help the sac slip into the barrel and past the
filling mechanism without twisting or getting hung up. I've never heard
of it being used to prevent ossification. Who are these experts who are
recommending storing sacs in talcum powder to prevent the oils in human
hands from attacking the rubber? --- B

On Fri, 4 Feb 2005 15:16:36 -0500, "Maria Ripanykhazova"
news.rnc.com wrote:

....
All the experts say to put the sack in french chalk (I think they mean
talcum powder?) after you buy them to prevent this. You just put a tiny
amount in the bag or box where it is being stored and shake it around a bit.

Isn't talc in powder form considered a substance that should be
avoided? http://www.preventcancer.com/consume...etics/talc.htm

BL wrote:

Those sacs just don't sound right to me. I think they're defective. Why
would a lightweight piece of pliable rubber flatten out like that?
Sounds like the rubber is breaking down. Bet this new one will fail in
no time *flat* too. Don't bother blowing the thing up unless you can
get the whole operation on a dig movie camera and post a link here...
I'd pay to see that one. Good luck, Ada. Want me to send you some
good sacs? -- B


Apologies for my slow reply - didn't check aspp for a few days. I haven't got a
movie camera so I would have to say no to me performing some stunt show and
posting it on the web! What's your store's url on the web and how much do
you sell your sacs for?