On 1/13/2006 at 4:58 PM Dwight Elvey wrote:
I'm not sure, not being an expert, but your
problem
sounds like an issue of the flux not holding up to the
temperature.
You should check with the manufacture of the solder
to find what they recommend. Also, sometimes welding
supplies will have some info as well.
Checked with the manufacturer's web site and they say it's good for
solders, including lead-free) with liquidus below 700F (371C). I think the
problem is more like this:
Sn95Sb05 alloy flow temp: 232-240C
Sn65Pb35 alloy flow temp: 183-247C
The Sn65Pb35 alloy is the eutectic alloy; i.e. there's no plastic range to
speak of; it's either solid or it's liquid. Compare an 8C range with a 64C
range and it's immediately apparent why the lead-based solder works better.
At least that's what I think. If I were soldering connections on a PCB,
there would be no problem, but when working with large sheet metal joints,
maintaining uniform heating is very difficult.
Still, there are lots of new alloys out there, and one might be just the
ticket if I can find it.
Cheers,
Chuck