Acid Core Solder

[Neil Morrison]

The whitish coating is just the plating. I suspect this has been
stored somewhere damp.
You can't solder to corroded 'anything' - soldering is 90% cleaning
and 10% heating.

Get a solder sucking iron from Radio Shack, and suck off as much
solder as you can.
Clean the lands, try a wire soldering brush, also from Radio Shack,
and rosin flux.
Then wet the lands. Once you have a solder coating the rest should be
OK.

If you truly, truly are convinced about the acid core solder, I would
soak the board in clean water with baking soda dissolved in it. Let
it sit there for an hour, say, then let it drip dry for a couple of
days. You'd be surprised how much that helps - I used it on a tea
soaked portable CD player, and I know of it being used on pocket
radios dropped in the ocean.

Regards,

Neil

----- Original Message -----
From: "Richard H. Arland" <rarland at EARTHLINK.NET>


> ....
> Nothing appeared to be broken or mangled, however, there was a
peculiar
> whitish coating on all the mild steel hardware. Apparently the unit
had
> some stainless steel nuts and lock washers which were not affected,
but
> all the mild steel inside the VTVM had this weird whitish coating.
The
> coating would rub off slightly when touched.
> ....
>
> In almost 40 years of building kits and playing the BA restoral
game, I
> have never come across this particular phenomenon. I am thinking
that
> this meter may have been constructed using acid core solder. Anyone
out
> there in BA land ever encountered something similar to this:
whitish
> power residue and the inability to resolder PC pads?
>
> 73 Rich K7SZ

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