On Dec 1, 15:28, Marvin Johnston wrote:
>
> Pete Turnbull wrote:
> >
> > > For quite a while, I had a small bottle of Acid Flux that was
> > basically
> > > Muriatic Acid, and it worked like a charm.
> >
> > Actually, it was probably mostly zinc chloride, made by dissoving
> > granular zinc (or old battery cases) in hydrochloric acid. Known
here
> > as Bakers Fluid. The raw acid would be too strong, and lose its
> > efficacy too quickly.
>
> No, it was Muriatic Acid according to the label. I went looking for
it
> after I ran out (it lasted about 10 years) and when I couldn't find
it,
> I bought the Muriatic Acid.
I'm surprised -- but I'm sure you're right.
> My understanding is that Muriatic Acid is
> 33% strength Hydrochloric Acid.
Sounds about right. Concentrated pure hydrochloric acid is about 36%
w/v; left exposed to air it fumes and gradually loses HCl; common
concentrated acid is 32%-33%. Muriatic acid is a technical (well,
industrial, really) grade and contains impurities as well as being
subject to loss. Be careful with it; apart from its corrosive nature,
you know you're not supposed to store it in proximity to certain other
things, such as ammonia, bleach, etc?
> I used quite a bit of it for cleaning
> tin-lead plating when I still owned the printed circuit shop. To head
> off comments I've heard before, tin-lead gets plated (NOT solder),
and
> the tin-lead later in the process gets fused to form the solder
alloy.
*I* won't argue with that description :-)
--
Pete Peter Turnbull
Network Manager
University of York
Received on Mon Dec 01 2003 - 19:44:11 GMT