Matt et al,
I was thinking in terms of using it to "plate" a circuit board to
protect against corrosion, i.e., not having to go the Tinnit route.
So far, I haven't done much surface mount work other than SOT-23
packages, but I recently got a bunch of SOIC-8 devices to use. I
didn't really have any thing against Tinnit, kind of a hassle with the
heating and all, although my wife swears that it scored her stainless
steel sink!
After reading the posts on the plumbers' paste, I also bought some
"Oatey Instant Solder" paste to at least keep for my plumbing
emergency repair kit. It's lead-free solder and active flux. the
ingredients listed are Zinc Chloride, Tin, Copper and Bismuth. It has
the stated precaution to avoid contact with skin. Presumeably, this
is the "plumbers' paste" that's been talked about here in the group,
or something similar.
In a previous response, Stephan (I think, or maybe Myc) last week
addressed my question regarding the typical use of acid flux instead
of rosin flux for plumbing. He made the point of saying that the
board had just been exposed to a lot of acid (Ferric Chloride). On
the Elecraft web site, they caution against using even any flux that
is advertised as being "water cleanup" due to some residual effect and
subsequent reactions with the electronics components.
I guess my question is, what's left behind after isopropanol cleanup
in the use of these pastes (Radio Shack or Oatey plumbing paste), and
is it mixed in with the solder layer such that corrosion will occur
after soldering the components with 63-37 tin-lead rosin-based solder?
Regards,
Ted
--- In
Homebrew_PCBs@yahoogroups.com, "matt clement"
<buckeyes1997@...> wrote:
>
> I have used the RS solder paste. I think they call it bearing
> paste. It works okay for larger items, but tends to ball up alot.
> The little balls of solder then go all over the board and find homes
> where you dont want them (ie between IC pins). It was easy to work
> with but the size of the solder "balls" in the paste are too large
> to do fine surface mount stuff with. The real surface mount paste
> that we use has a much much finer solder ball diameter in the flux.
> I hope that made helps.
>
> Matt
>
>
>
>
> --- In Homebrew_PCBs@yahoogroups.com, "kilocycles" <kilocycles@>
> wrote:
> >
> > Yeah, well I bought the heat gun primarily because I was tired of
> > charring my heat shrink over wire connections (and burning my
> fingers
> > with a butane lighter). That, and the fact that my pro painter
> wife
> > can use it for stripping. Paint, that is.
> >
> > As long as nothing is left behind but solder after cleaning the
> board,
> > the plumbers' paste sounds ok...I'll certainly give it try.
> >
> > Changing the subject ever so slightly, I bought a tube of Radio
> Shack
> > solder paste, and they don't say exactly what it's supposed to be
> used
> > for. I've been told it's not suitable for use as an SMD paste;
> it's
> > about 1/10 the price. I was thinking of trying it first to make
> the
> > solder joints in copper boxes used a compartments in my ham radio
> > projects. Any experience with the Radio Shack stuff?
> >
> > Ted
> >
> > --- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
> > <stefan_trethan@> wrote:
> > >
> > > It's washed off after tinning so the acid flux is not a problem
> > (remember
> > > the board was immersed in a pretty nasty etchant not long ago).
> > >
> > >
> > > If you buy a heatgun, you really want a temperature controlled
> one
> > (closed
> > > loop). I had a cheap one, and now a good steinel with temperature
> > display,
> > > and the difference is stunning. Costs like 10 times as much
> though,
> > but
> > > is about 100 times as useful..
> > > For PCB tinning alone you might get away with the cheap one,
> since
> > you are
> > > not using different nozzle attachments and you can work out a
> suitable
> > > distance once and then stick with it.
> > >
> > > ST
> > >
> > >
> > > On Tue, 09 May 2006 03:21:30 +0200, kilocycles <kilocycles@>
> > > wrote:
> > >
> > > > Myc,
> > > >
> > > > What's in that plumbers' paste? Nothing that will react with
> the
> > > >
> > > > electronic connections (like acid flux copper pipe solder) I
> presume?
> > > >
> > > >
> > > > I bought a 1500 Watt heat gun on sale at Harbor Freight for
> $12, and I
> > > >
> > > > think that might get it hot enough.
> > ---snip---
> >
>