[R-390] Desoldering part 2

[wli]

Standard procedure is to heat and unwrap using needle-noses and dental picks. This puts a lot of stress and torque on the post, and can fracture them, as we have seen.  What I do, is first clip off the wrapped lead of the offending component flush with the post using a real sharp flush wire cutters, whose nose has been filed narrow. Then with a hot 100W narrow tip iron, touching the post momentarily causes that component to literally fall off. It takes only seconds to just heat those portions of the post holding the old lead, and lessens the damage caused by conducted heat to neighboring components like resistors or coils.


Principle is to use a hot enough iron to loosen the solder for removal, and not heat up the entire assembly. 

Reassembly is another matter, since now the entire post and other leads require cleaning and re-tinning, and you should use hemostats or other narrow heat sinks to prevent collateral thermal damage.

At least, that is my routine........    W. Li