evil_lurker
National Hazard
Posts: 767
Registered: 12-3-2005
Location: United States of Elbonia
Member Is Offline
Mood: On the wagon again.
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Accidently broke my thermometer and adaptor...
Did it while cleaning last week. My hotplate cord caught my distillation head/thermometer adaptor/thermometer and knocked it off the table. My
thermometer broke and just happened to crack the adaptor joint as well.  Poof,
there went about $50.
I ordered replacements from United Glass Tech and they arrived this afternoon.
I decided to upgrade to a screw type with teflon bushing. Its nice but the freaking thermometer won't stay straight when you screw it down.
Is this normal?
It appears that the bottom part of the bushing is good and tight, the top is just about 1-2 millimeters or so too wide. 
I'm thinking I'm going to have do some drilling, and add in another "O" on top to make a bushing for the bushing....
Think that might work?
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Rosco Bodine
Banned
Posts: 6370
Registered: 29-9-2004
Member Is Offline
Mood: analytical
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Teflon tape the thermometer stem to make a tapered
thickness wrapping and then just twist it firmly into
the adapter as a jam fit , friction fit sort of arrangement .
Teflon is soft enough to form fit itself in the opening
and make a secure joint that is moderately pressure
tight and vacuum tight . This also works inside a
10/30 female taper joint . A thermometer stem is ~6mm
so you only need a bit over a .5mm thick wrapping at
the start and then build up the wrap thickness to a bit over 2mm thickness with a spiral wrap about the same
length of 30mm , and presto you have a good substitute for an overpriced and unnecessary ground jointed
thermometer . The spiral wrap only needs to reasonably approximate the shape of the cavity into which it will be firmly inserted with a twist , as it
will form fit itself closely
as the material deforms under pressure . It works the same way with a cylindrical or slightly throated opening
as it does with a tapered joint , just tape wrap the stem
and twist it in .....works like a charm .
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evil_lurker
National Hazard
Posts: 767
Registered: 12-3-2005
Location: United States of Elbonia
Member Is Offline
Mood: On the wagon again.
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Fixed.
Used a 23/64 drill bit and carefully hand reamed the teflon adaptor several millimeters deep (if I had one I'd started out with an 11/32).
Dug around in my O-ring kit and found two black rubber o-rings the same diameter as the viton on the bottom.
The thermometer is lined up pretty good right now.
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