"mjb920" wrote in message
ups.com...
Slightly off-topic, and maybe stupid, but is it possible to overheat
the copper pipe itself with either propane or MAPP? It seems to
discolor with prolonged heating.

In my experience overheating causes more soldering problems than anything
except lack of cleanliness. For successful soldering: clean both surfaces
thoroughly, flux, heat rapidly just until solder melts thoroughly, apply
solder, cool. A torch flame can easily overheat part of the joint without
the rest being hot enough and practice helps a lot. A good job is usually a
quick job.

Don Young