I've tried thinning old dry paste with denatured alcohol and the result was that the components popped off the board like popcorn as soon as I heated it up.

ST

On Thu, Nov 7, 2019 at 3:35 AM Charlie Hansen <n0tt1@...> wrote:

Thanks Donald....

So, in a way it's like paint...solvent evaporates and the solids settle
out.

I just wonder what chemical the "medium" is....and if more of the same
were added and mixed would that prolong its life even more?? Now, that's
with evaporation....oxidation is quite another issue.? Any thoughts on
that?

Charlie


On Tue, 5 Nov 2019 18:51:04 -0500 "Donald H Locker"
<dhlocker@...> writes:
> The medium carrying the solids changes viscosity as it ages and
> evaporates and oxidises and/or reduces); the solder balls settle as
>
> gravity exerts its ever-present force; the flux reacts with the
> vehicle
> and solder reducing the fluxing potency and the vehicle viscosity
> and
> solder wettability. There are probably other effects, but those are
> the
> big ones that I've read about.
>
> Donald.
> --
> *Plain Text* email -- it's an accessibility issue
> () no proprietary attachments; no html mail
> /\ <>
>
> On 2019-11-05 6:30 p.m., Charlie Hansen wrote:
> > "> Be aware that the rated shelf life is anywhere from 6 months to
> a
> >> year.? It lasts longer if you keep it refrigerated, especially
> after
> >> breaking the seal."
> >
> > Guys, there's something I always wanted to know about that shelf
> > life....what the heck causes the stuff to go bad?
> >
> > Charlie
> >
> >
> > On Tue, 05 Nov 2019 14:51:58 -0700 "Dwayne Reid"
> <dwayner@...>
> > writes:
> >> Hi there.
> >>
> >> We have been purchasing 63/37 solder paste from Chip Quik? -
> both
> >> direct and via Digikey.? It's available in both syringe and jar
> >> form.
> >>
> >> Be aware that the rated shelf life is anywhere from 6 months to
> a
> >> year.? It lasts longer if you keep it refrigerated, especially
> after
> >>
> >> breaking the seal.
> >>
> >> We normally purchase the Water Soluble flux version - we then
> just
> >> wash the boards under running hot water and blow dry with
> compressed
> >>
> >> air.? This works especially well for the small prototype board
> runs
> >> that we do.
> >>
> >> dwayne
> >>
> >>
> >> At 10:39 AM 11/5/2019, Dave wrote:
> >>> I have plenty of regular solder, and plenty of flux, now I need
> to
> >>
> >>> buy some solder paste for smd stuff. Any recommendations? I
> would
> >>> like some in a jar and also a syringe just to have both. Is
> >> no-clean
> >>> solder better? Also, I just want tin/lead solder if it is still
> >> available.
> >>>
> >>> Thanks,
> >>>
> >>> Dave
> >>
> >>
>
>
>
>