Joined: Sun Aug 03, 2003
2:02 pm Posts: 451 Location: Erie, PA
This afternoon I was doing some
soldering of copper plumbing (moving the washing
machine connections in the basement) and ran into
an unexpected situation where the propane torch
was not able to deliver enough heat because of the
large amount of copper fittings in the immediate
area. I was using the standard Pb-Free plumbing
solder (SnSb5), which has a melting temperature
of around 235 °C.
It just wasn't going to
work. I pulled out the MAPP/Oxygen torch, but alas
the Ox bottle was empty. What to do?
fortunately I have a good stash of the good old
60/40 PbSn solder, which has a melting temperature
of around 188 °C. That's 45 degrees lower - pretty
It worked. The solder flowed
readily into the joints using the propane torch,
and as a bonus, the comforting signature shiny finish
resulted. Lead-free solders are dull when cool...
the way we used to know to spot a cold solder joint.
Since the downstream flow goes only to a washing
machine, I am not concerned about the lead content
(not that I would be anyway, since the 1950s vintage
house is filled with it).
So, this is a good
reminder for anyone else facing a similar situation
whether with a plumbing project or with an electrical/electronic
project that is difficult or impossible to solder
due to not being able to transfer enough heat.