I'm still an old-fashioned fan of rubber tubing rather than Tygon
tubing. For normal lab operations, where the tubing carries water
for
cooling, rubber tubing has awlays worked well, is easily connected to
faucet
adapters and glass condensers, and is easily removed at the end of an
experiment. Just get the correct size to fit the
apapters/conncectors
snugly, not too large, not too small with a wall thickness suitable to
the job
at hand. Also, the flexibility of the rubber tubing allows for
better
construction of distillation apparatus, etc.
Tygon tubing can be difficult to connect (for some reason, what's
available
in the lab is not always the correct diameter), can slip off a condenser
if not
pushed on far enough, and can be difficult to remove after as
little as 30
minutes. Also, there is not enough elasticity to Tygon tubing and
softening it
with solvent, to connect it initially, makes the removal more
difficult.
In my 40 years of experience, most of the problems with tubing sticking
to
glassware, where a device is needed to remove it, it was Tygon-type
tubing.
When Tygon, or another chemically resistant tubing is needed for
apparatus,
the best rule is, if it is not removed easily, leave it alone and call
the lab
professional who knows how to safely deal with the problem.
David
____________________________________________________________________
_____
David A.
Katz
Chemist, Educator, Expert Demonstrator, Science Communicator,
and
Consultant
Programs and workshops for teachers,
schools,
museums, and the public
133 N. Desert Stream Dr. * Tucson, AZ
85745-2277 * USA
voice/fax: (520) 624-2207 * email:
dakatz45**At_Symbol_Here**msn.com
Visit my web site:
http://www.chymist.com___________
______________________________________________________________
----- Original Message -----
Sent: Tuesday, November 10,
2009 10:16
AM
Subject: [DCHAS-L] Tool
selection for
removing hoses from glassware
We=92ve been looking hard at our hand injuries
lately and are
focusing on cutting tool and glove selection. One thing in
particular
that we haven=92t been able to come up with a good solution for is a
tool that
works well for removing tubing that has basically seized or =93become
one with=94
the glass connections on condensers, cold fingers, etc. I=92m
sure you=92ve
seen this before and most people reach for their pocket knife or a
razor
blade. It generally ends badly. Either the blade slips or
the
glass breaks and in either situation we end up with stitches.
Anyone
found a tool that works better under these conditions?
Kim
Kimberly
Begley
Jeskie, MPH-OSHM
Operations
Manager
Physical
Sciences
Directorate
Oak Ridge
National
Laboratory
(865)
574-4945