[R-390] Desoldering part 2

[Charles Steinmetz]

W. Li wrote:

>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.

The turret terminals are so fragile, and such a pain to replace (if 
you can even find replacements), that cutting the leads before 
desoldering is mandatory.  Even if you don't know the part is bad, 
cut the lead.  If afterwards it is too short to reattach, replace the 
part even if it's still good.

Cutting leads before desoldering is also very useful generally in 
both point-to-point and PCB construction.

If possible, it is helpful to unmount the terminal from the chassis 
before unsoldering.  That way, you can't put any force on the fragile 
insulator while you are wrestling with the wires.

When working in close quarters, use scraps of glass-epoxy circuit 
board material (or similar fireproof insulating sheets) to isolate 
the joint you are working on so you don't accidentally burn other 
wires and parts with your soldering or desoldering iron.

Finally, troubleshoot with your meters and your brain, not with your 
soldering iron, and this issue will not come up so often.

"Oblique" or "angled head" cutters are extremely useful for reaching 
into close quarters and clipping leads in both point-to-point and PCB 
construction.  For example:

<http://www.micro-tools.com/store/P-32728/Flush-Oblique-Front-Cutter.aspx>

<http://www.micro-tools.com/store/P-45821/Esd-Safe-Flush-Cut-Cutters-45.aspx>


Best regards,

Charles