Flux storage for extended periods - Page 1
Forum section: electronics / general

author: GingerGeek
author_rank: Newbie
timestamp: September 14, 2025, 08:19:39 am
content: Hi to anyone who may have clicked on this very boring postI Just wanted to ask how people store their flux for long periods of time.Back in the days when I ran my repair company I used Inventech AMTECH NC-559-xx purchased from a listed distributor. Due to the cost and the volume it was stored in refrigeration.These days I am just starting back into hobby level engineering. Since the wife is not keen on flux in with the milk and butter I wanted to know what others do to store flux that might be sitting around for a while... mini fridge? thrown in a draw?

author: Traceless
author_rank: Frequent Contributor
timestamp: September 14, 2025, 11:37:51 am
content: I store it on the shelf inside a sealed food container similar tothis. No refrigeration. Also should note the flux is of course not directly inside the container. I buy syringes and store them in that box.

author: Psi
author_rank: Super Contributor
timestamp: September 14, 2025, 11:41:49 am
content: I store the big container in the fridge in the same box as the solder paste and glues, but I have a smaller syringe of flux that is kept at the work bench at room temp. I refill it from the fridge from time to time.

author: GingerGeek
author_rank: Newbie
timestamp: September 14, 2025, 07:06:41 pm
content: Well I was thinking about one of these ...

author: wifikebab
author_rank: Contributor
timestamp: September 15, 2025, 07:59:54 am
content: Quote from: Psi on September 14, 2025, 11:41:49 amJust curious, what sorts of glues are you storing in your fridge? Wondering if I'm not storing things the way I should. Matter of fact, I've just been keeping my SMD291NL at room temperature 24/7.

author: Berni
author_rank: Super Contributor
timestamp: September 15, 2025, 08:20:09 am
content: A lot of these cheap peltier based mini coolers are so inefficient that they don't reach 5°C and are not even regulated, they just run full power.Here we keep the paste in a tuperware container inside a mini fridge. Not sure how much refrigeration extends the life of solder paste, we still end up changing it out around once a year. I think flux evaporation from being exposed to air in an open container is a bigger factor.As for flux, we don't keep it refrigerated, seams to hold up fine, tho some do turn into a more brown color over time. Seams to still work fine.

author: Smokey
author_rank: Super Contributor
timestamp: September 15, 2025, 08:24:56 am
content: A silicon steel toroid can store up to about 2T, which is a lot of flux! That's my vote.Seriously though, I don't refrigerate my tube of tacky flux and it's been good for over a year now. Solder paste on the other hand, even the stuff they claim you don't have to refrigerate, always goes in the back of the fridge. I just had some dry out, and it messed up my assembly plans.

author: Psi
author_rank: Super Contributor
timestamp: September 21, 2025, 12:17:37 pm
content: Quote from: wifikebab on September 15, 2025, 07:59:54 amCyanoacrylate glues mostly, they tends to last longer in the fridge.You're much less likely to go to use it and find it has all set in the container if it's stored in the fridge.My fridge storage mainly exists for solder paste, but I keep other stuff there too, since in general colder temps are usually better for storing most things.

author: Obsidianxenon
author_rank: Contributor
timestamp: September 23, 2025, 03:59:46 am
content: Not sure what kind of flux you have, but I store my rosin flux in a drawer. If you have one of those syringe-style fluxes, you'd probably also be right to store it in a drawer. If you have active flux (the corrosive stuff), you should look into getting some different stuff.If you have a lot of flux, then you should store the majority of it in the fridge, along with solder paste.

author: MathWizard
author_rank: Super Contributor
timestamp: October 01, 2025, 03:36:35 am
content: I bought some SMD solder paste years ago, I think I used it once. I'm pretty sure people keep that stuff in a fridge. So I wonder what state mine is in after years of sitting in a box. It was in a little jar with screw on cover though.What about sunlight, does that damage any flux ?? And how much does any flux react with oxygen over time, say like if the cover was left off it ??I use MG chemicals RA flux, it's pretty strong, but can leave a conductive residue. I also cheap waxy rosin stuff. I keep the lids on them, and they do just fine on the shelf.

author: Psi
author_rank: Super Contributor
timestamp: October 01, 2025, 04:29:23 am
content: Quote from: MathWizard on October 01, 2025, 03:36:35 amI only use RMA flux, seems to work well enough, never had an issues where i wanted stronger flux. RA kind of scares me a bit.