[TowerTalk] solder

[Andy]

On Mon, Jan 11, 2010 at 1:42 PM, Craig Clark <jcclark at radiusnorth.net> wrote:
> "Hello to all on TT. I have a roll of old solder. the label states made in
> england. Alloy Sn 50 ersin muliticore 5 core solder. non-corrosive flux.

Ersin Multicore (made in England) was a very nice solder for
electronics, quite popular in its day, before RoHS came along.

I don't know much about the 50-50 blend.  It apparently makes the
solder solidify more slowly as it cools, which is (was) advantageous
in plumbing.  That probably makes cold solder joints more likely if
you're not careful.

> ... Im
> just not sure if it contains lead which is bad.

I'm pretty sure it contains lead.

So does the Kester 63-37, the 60-40 and most "electronic grade solders".

Lead-free solder does have problems with whisker growth (similar to
dendrites but not the same), leading to short circuits.  I think this
is why lead-free solder is not used in high reliability applications
like satellites and the military.  This was discovered decades ago,
before lead was added to electronic solders (and effectively fixed the
problem).

Lead was taken out of plumbing solder long ago because it does leach
through the joint into the water.  For a long time they didn't think
it could, but measurements showed otherwise.

Andy