This Hobby Is Actually Useful!

Brent Hilpert hilpert at cs.ubc.ca
Sat Aug 1 17:49:01 CDT 2015


On 2015-Aug-01, at 2:38 PM, Paul Koning wrote:
>> 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.

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.



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