[Mgs] soldering corroded copper

[PaulHunt73]

There is flux and flux.  Soldering flux i.e. in cored solder can only remove 
microscopic layers of oxidisation from basically clean copper, it won't 
remove corrosion.  Acid flux as in a paste typically contains hydrochloric 
acid and may well be able to remove heavier corrosion, but then you have to 
completely remove that flux or it continues to eat away at everything.  Wire 
wool should be able to clean the copper rivets, also the copper tracks but 
you may abrade them away.  In the past I've repaired fractured and burnt 
tracks by wrapping a strand of copper round the component terminal and laid 
it along the track for an inch or so.  Should be easy enough on a 69 vintage 
circuit board, less so today!

PaulH.

----- Original Message ----- 
> Get some Flux, it will eat the corrosion and allow the solder to bond. 
> It's
> a paste when you heat up the area with soldering iron it will clean the
> connection.
> Subject: [Mgs] soldering corroded copper

> Generic question for the metallurgy gifted:  What chemical do you 
> recommend
> for cleaning away copper corrosion so I can solder electrical connections?