Permanent labelling of -150degC metal racks?

[Wendy Ingram]

Hi Wo,

You might like to try what we do here - "dog tags" attached with a short 
length of brass bead chain to the handle of each rack. I haven't tried 
these at -150, but have used them for a long time in -80 freezers so I 
don't think there would be any problem. Our tags are about 3 cm diameter 
circles made of brass and engraved with a big black letter or number.

The great thing with these is they are easy (and reasonably cheap) to 
get as they are used heaps in heavy industry for permanent labelling of 
pipes, valves etc. You can buy sets already pre-engraved (e.g A to Z or 
1 to 20, 1 to 100 etc) from industrial safety shops, and many can also 
do custom engraving of blanks. We get ours from Seton (they are a big 
company in USA and Australia etc, no affiliation), where they are called 
"brass valve tags".

Very easy to see through frost and ice, plus easy to wipe. In my 
experience they go forever.

Cheers,
         Wendy.

-- 
Wendy Ingram, PhD
Senior Research Officer
RCH Cancer Research Laboratory
Phone: +61 7 3636-9211
Fax:   +61 7 3365-5455
Email: w.ingram atatat uq.edu.au

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