1 Aug
2015
1 Aug
'15
3:49 p.m.
On 2015-Aug-01, at 2:38 PM, Paul Koning wrote:
As an example, I was trying to solder on the ground-plane of a 1970s (i.e. leaded
everything) Heath digital tuner recently (double-sided ground plane on the PCB).
Old Weller 48W/700F/mag-temp-switch iron was not up to it, would only melt in immediate
proximity to the tip.
On Aug 1,
2015, at 5:24 PM, Robert Jarratt <robert.jarratt at ntlworld.com> wrote:
PS A related question. I struggled somewhat with the Weller Magnastat No. 8
tip, when trying to solder leads to the ground plane, I could not get the
solder to stay molten very long. I was using lead-free solder, its melting
point is much lower than the temperature which a No. 8 tip reaches. The iron
is 50W. Clearly the ground plane was taking heat away, but is it a problem
with the tip not being hot enough, the iron not powerful enough, or perhaps
some operator error?
Politically correct solder is harder to use and has a higher melting point. I asked one
of the professionals at the office about it; her answer was to avoid it unless it was
required for the job. In other words, for hobby use and for anything else that isn?t
sold, stay away from it. Modern components are perfectly happy being soldered with real
solder, even though they are made lead-free.
I followed that advice and was very happy with the outcome.
Meanwhile, 50 watts isn?t all that much when you have a major heat sink. A ground plane
may be enough to give you trouble, but I suspect it?s the use of lead free solder that?s
the real issue.