Flux shelf life

[Steven GreenhoughParticipant @stevengreenhough56335]

What is the shelf life of Easyflow flux once mixed? I mixed up a small sachet I got off eBay when I tried my hand at silver solderint the other day. It’s been kept in a film cannister type container, with a lid. Will it still be ok after a week or so or will I need fresh?

[Steven GreenhoughParticipant @stevengreenhough56335]

[Michael Cox 1Participant @michaelcox1]

I keep my EasyFlo flux for months. I usually let it dry out and then re-moisten when needed.

Mike

Edited By JasonB on 13/04/2015 09:21:54

[JasonBModerator @jasonb]

Should be OK if its still moist, just add a bit more water if needed.

J

[Gordon WParticipant @gordonw]

In my experience it will last for ever. If it dries out just re-mix.

[Steven GreenhoughParticipant @stevengreenhough56335]

Thanks Jason.

[Steven GreenhoughParticipant @stevengreenhough56335]

And Gordon.

[Steven GreenhoughParticipant @stevengreenhough56335]

And Mike.

[Russell EberhardtParticipant @russelleberhardt48058]

It does undergo a slight change. The active compound, borax, absorbs water into its structure. That change isn't reversed just by drying out, only at higher temperatures. It can still be used but you will find that it foams up more than fresh flux. I still use it with no problems.

Russell

[Speedy Builder5Participant @speedybuilder5]

Good shelf life, but mix it in a glass / plastic pot as it will rust in a 'tin' pot. Dry powder is OK in a 'tin' pot though. Some folks mix it with water, some use meths, some put a drop or two of liquid soap with it.
BobH

[Phil PParticipant @philp]

I mix mine in a plastic 35mm film container, then snap the sealed lid on when finished.

It eventually does dry out but is easily re-mixed with more water.

Phil

[Keith HaleParticipant @keithhale68713]

To prolong the useful life of powder flux …………..

Add a couple of drips of the wifes' washing up liquid to the powder.

Mix to yoghurt consistency with water.

If it dries out in the future (and it will!) you will be able to remix it easily by adding more water. The absence of any detergent makes the re-mixing a bit of a chore.

Keith

[Ian S CParticipant @iansc]

I just mix enough for the job in a plastic bottle cap, if there's any left, it goes in the mix for the next time.

Ian S C

[Steven GreenhoughParticipant @stevengreenhough56335]

I might have another try at the soldering job this afternoon but before I do I’ll add a few drops of detergent. Thanks for all the replies guys.

[Keith HaleParticipant @keithhale68713]

And you will find the flux mixes easier and sticks better to your components.

Keith

[FMESParticipant @fmes]

I haven't tried mixing with detergent as I would have thought there would be a small amount of burnt residue to contaminate the joint.

What I HAVE tried is mixing a few drops of methylated sprit to the flux which I find helps cut any residual oil/grease (fingerprints etc) .

Lofty

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