Thermal Bath Fluid for Julabo FP 50


I acquired a used Julabo FP 50 but it didn’t come with any thermal bath liquid. Curious if I can use 200 proof ethanol or acetone or should I get the Julabo C5 Thermal Bath Liquid ($1,000 for 10L)? It smells like it has acetone inside.


hopefully it was denatured alcohol. so ethanol with iso and MEK.

Denatured ethanol or Isopropanol are way less likely to eat plastics and elastomers than acetone (but it could certainly be acetone). I doubt either EtOH or Iso has the heat transfer capacity of the Jubalo C5 fluid, but as Jubalo don’t actually list that in the specs (?!?), I’m only guessing…

Another advantage to running the fancy stuff is you can actually run above rm temp if you desire. that may not matter for your current application, but keep it in mind when you might want to run above OR below rm temp.

C5 lists 110C which means you could (for instance) bake out the jacketed material columns on your CLS, and still run them at -50C. or however cold that wee thing can keep your column(s). might only be -30C. if you’ve got something different on your solvent tank, then the FP50 might be able to keep a couple of 5lb columns at -40C most days.


Definitely use the bath fluid, there is a graphite bearing in these bad boys, I ran a 75/25 ethylene glycol, water mix and though the German headquarters approve this, the techs let me know about that graphite bearing.

Graphite hates water. Saved me loads of trouble long term, and probably repair money and that silicone bath oil is virtually indestructible and should (if properly taken care of) never have to be changed. Give Julabo a call and ask them for what approved cleaning fluid can be ran through it. I bet that smell is from someone trying to clean out whatever they were using as bath fluid to heat and cool.

Fixing chilers

Any recommendation on what could be used for the solvent tank? We will likely purchase one of these fp-50 to accompany our PX1.