From: "J.C.Wren" <jcwren(a)jcwren.com>
I have recently acquired a couple of build PC boards
that are not
solder
masked. There is some oxidation, ranging from minimal
to mild (mild being
the not quite green, but a very hard oxide, as if the tin had reacted with
something else). Anyone got any good ideas on cleaning these? I'd like
something non-submersible, since one of the boards contains keyswitches.
I have plenty of experience cleaning unbuilt boards. Normally, I'd
just
hit them with some super fine steel wool, or buff them
with 20lb paper.
And
I've repaired boards, but usually to get them
working, not to restore their
aesthetic appeal.
I've considered using a baking soda solution and a stiff bristle
brush.
This should neutralize any corrisive elements, and the
baking soda might be
abrasive enough to remove the oxides without damaging the board. It would
wash off easily enough with water, and I could protect the switches during
that process.
Hi
Baking soda assumes that it is acid that caused the corrosion.
If it was caused by leakage from NiCads, you'll need to use
something like vinegar to neutralize it.
You might try getting a fiber glass brush from a welding shop.
These are sometimes used to clean aluminum.
Sometimes it isn't the copper that is oxidized. They put a
layer of nickel between the copper and solder on most PC boards.
It may be nickel oxides ( bluish green ).
If there is any kind of salts ( neutral ) you'll still have
electrolytic corrosion. You need to make sure that it is well
cleaned before you are done, regardless of what you use.
Dwight
Anyone got any ideas or standard procedures for this kind of thing?
--JOhn