I've been upgrading my soldering mojo lately and have collected an assortment of liquid fluxes.

The Kester 951 and Kester 186 datasheets state shelf lives (1 and 2 years respectively) when stored between 10-25°C (50-77°F).

I store my solder paste in the fridge, which is between 2-5°C (35-40°F).

Is the liquid soldering flux safe in there too? And would keeping it there extend its shelf life?

Also I guess I don't know how I could tell it had gone past its prime. What would be the signs it had "expired", whether or not the shelf life period had elapsed?

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    \$\begingroup\$ This is just to pile-up references. Here's a recent article about handling of solder paste in the industrial shops. \$\endgroup\$ Commented Oct 16, 2015 at 20:05

1 Answer 1


I have a liquid rosin solder flux that I keep in my garage (40F-100F non-controlled temp). It is over 25 years old & it works perfectly even after that much time. I suggest you avoid any solder flux that requires refrigeration.

To answer your question--I doubt it will cause a problem for your flux. To be on the safe side though, I would suggest you consult the manufacture's website or contact them via email/phone--which ever is easiest for you.


Best regards


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