8 Apr
2002
8 Apr
'02
9:10 a.m.
This reminds
me, these acoustic couplers may need some periodic
maintenance, such as putting some talcum powder on the rubber pieces
that hold the telephone handset.
I've also seen it recommended for refrigerator door gaskets.
What talcum would do to protect rubberized plastic from
deteriorating is a mystery to me. Are we talking about
actual latex in any of these situations? I think not.
I would guess these rubbers harden or goo-ify over time
due to something other than lack of talc, such as long-term
exposure to UV or ozone or absorption of volatiles from
other plastics.
I have an old Anderson-Jacobsen 300 baud modem in a wooden
box that needs a new home, I think... 
8 Apr
8 Apr
10:50 a.m.
Ahh, then my Anderson Jacobson Model A 242A is likely to be
the third generation model. It is interesting to note that
along with the changes in model technology, the handsets on
telephones have changed enough over the years that few will
even still fit properly into the old acoustic couplers any
longer.
--tom
At 10:10 AM 4/8/02 -0400, you wrote:
The wooden ones are the original, 1st generation AJ's, IIRC...
I have the second-generation plastic shell that assembles
with an aluminum "waistband" and allenhead screws. The
third generation used thinner plastic clamshells and no
waistband, just some tapered Philips-head screws. The
3rd generation was also limited to 300 baud, while my
2nd generation could do 450 & 600 using the 300 standard
(Bell 101?).
-dq
-Douglas Hurst Quebbeman (DougQ at ixnayamspayIgLou.com) [Call me "Doug"]
Surgically excise the pig-latin from my e-mail address in order to reply
"The large print giveth, and the small print taketh away." -Tom Waits
This
reminds me, these acoustic couplers may need some periodic
maintenance, such as putting some talcum powder on the rubber pieces
that hold the telephone handset.
I've also seen it recommended for refrigerator door gaskets.
What talcum would do to protect rubberized plastic from
deteriorating is a mystery to me. Are we talking about
actual latex in any of these situations? I think not.
I would guess these rubbers harden or goo-ify over time
due to something other than lack of talc, such as long-term
exposure to UV or ozone or absorption of volatiles from
other plastics.
I have an old Anderson-Jacobsen 300 baud modem in a wooden
box that needs a new home, I think... 
1:27 p.m.
Soft latex-rubber (non vulcanized) is very sensitive to free H2
(hydrogen-gas) that is avialble in the atmosphere at very low
concentration (~0.01% by volume)
Remember the partyballoons that loose their festive appearance
after a few days? H2 is the culprit!
By applying talcum or "non corosive" fat/oil the rubber will effectively
be isolated from the H2 in the atmosphere, Oil, however, is not very
handy if you want to use the rubber for pulleys or drivebands. Talcum
can be used if applied sparingly, while maintaining a comfortable level
of friction
I've fixed shriveled-up pulleys from cassette-recorders by submerging
them in arachide-oil for a few hours. Removing the surplus oil (repeatedly)
with a mild detergent or alcohol, and applying a bit talcum for preventive
maintenance. It's important to let the rubber sweat out the oil for a few days
and remove the surplus oil again if needed, before putting the rubber back
to active use (oil sticks to tapes and those will be eaten by the recorder
or the tapedrive).
Sipke de Wal
--------------------------------------------------------------
http://xgistor.ath.cx
--------------------------------------------------------------
What talcum
would do to protect rubberized plastic from
deteriorating is a mystery to me. Are we talking about
actual latex in any of these situations? I think not.
8312
days inactive
8312
days old
2 comments
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dquebbeman＠acm.org -
sipke＠wxs.nl -
uban＠ubanproductions.com